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Rapid evaluation is critical after trauma and with symptoms such as weakness, headache, and dizziness, which is why CT is the modality of choice in these scenarios. Exceptional image quality is key to optimize diagnosis, and lower dose imaging minimizes risk to the patient.

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Issue Number 26/May 2010International Edition

On account of certain regional limitations of sales rights and service availability, we cannot guarantee that all products included in this brochure are available through the Siemens sales organization worldwide. Availability and packaging may vary by country and is subject to change without prior notice. Some/All of the features and products described herein may not be available in the United States.

The information in this document contains general technical descriptions of specifications and options as well as standard and optional features which do not always have to be present in individual cases.

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Cover Story The Best of Both Worlds in Neuro ImagingPage 6

News Best Balance Between Image Quality and Reduced DosePage 18

Business More for Less in MonacoPage 28

Clinical ResultsSOMATOM Defi nition AS+: CT Perfusion With Extended Coverage for Acute Ischemic StrokePage 50

Science CT in Pediatrics: Easier and Safer With the FlashPage 62

Somatom_26_Umschlag_INT.indd 1 07.05.10 10:32

“Neuro BestContrast allows radiologists to better visualize subtle edemas as well as subtle signs of stroke, and to better delineate the cortical margin.”

David S. Enterline, MD, Duke University Medical Center in Durham, North Carolina, USA

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Responsible for Contents: André Hartung

Editorial Board: Andreas BlahaHelge BohnAndreas FischerThomas Flohr, PhDJulia HoelscherKlaudija IvkovicAxel LorzPeter SeitzStefan Ulzheimer, PhDAlexander Zimmermann

Authors of this IssueH. Alkadhi, MD, Institute of Diagnostic Radiology, University Hospital Zurich, Zurich, Switzerland

F. Bamberg, MD, Department of Clinical Radiology, University of Munich, Campus Großhadern, Munich, Germany

R. W. Bauer, MD, Department of Diagnostic and Interventional Radiology, Clinic of the Goethe University, Frankfurt, Germany

Note in accordance with § 33 Para.1 of the German Federal Data Protection Law: Despatch is made using an address file which is maintained with the aid of an automated data processing system.SOMATOM Sessions with a total circulation of 35,000 copies is sent free of charge to Siemens Computed Tomography customers, qualified physicians and radiology departments throughout the world. It includes reports in the English language on Computed Tomography: diagnostic and therapeutic methods and their applica-tion as well as results and experience gained with corresponding systems and solutions. It introduces from case to case new principles and procedures and dis-cusses their clinical potential.The statements and views of the authors in the individual contributions do not necessarily reflect the opinion of the publisher.The information presented in these articles and case reports is for illustration only and is not intended to be relied upon by the reader for instruction as to the prac-tice of medicine. Any health care practitioner reading this information is remind-ed that they must use their own learning, training and expertise in dealing with their individual patients. This material does not substitute for that duty and is not intended by Siemens Medical Solutions to be used for any purpose in that regard.

A. Becker, MD, Department of Clinical Radiology, University of Munich, Campus Großhadern, Munich, Germany

C. R. Becker, MD, Department of Clinical Radiology, University of Munich, Campus Großhadern, Munich, Germany

G. Feuchtner, MD, Institute of Diagnostic Radiolo-gy, University Hospital Zurich, Zurich, Switzerland

M. Fischer, MD, Institute of Diagnostic Radiology, University Hospital Zurich, Zurich, Switzerland

R. Goetti, MD, Institute of Diagnostic Radiology, University Hospital Zurich, Zurich, Switzerland

W. Heindel, MD, Department of Clinical Radiology, University Hospital, Münster, Germany

J. M. Kerl, MD, Department of Diagnostic and Interventional Radiology, Clinic of the Goethe University, Frankfurt, Germany

M. Lell, MD, Department of Radiology and the Imaging Science Institute (ISI), University of Erlangen-Nuremberg, Erlangen, Germany

S. Leschka, MD, Institute of Diagnostic Radiology, University Hospital Zurich, Zurich, Switzerland

K. Lin, MD, Department of Radiology, New York University Langone Medical Center, New York, NY, USA

A. H. Mahnken, MD, RWTH Aachen University Hospital, Aachen, Germany

Y. Mizutani, MD, Department of Radiology, Sakakibara Heart Institute, Tokyo, Japan

K. Nikolaou, MD, Department of Clinical Radiology, University of Munich, Campus Großhadern, Munich, Germany

J.-F. Paul, MD, Centre Chirurgical Marie Lannelongue, Le Plessis-Robinson, France

A. Plass, MD, Clinic of Cardiovascular Surgery, University Hospital Zurich, Zurich, Switzerland

B. Policeni, MD, Radiology Faculty, Neuroradiology, University of Iowa Hospitals and Clinics, Iowa City, Iowa, USA

H. Scheffel, MD, Institute of Diagnostic Radiology, University Hospital Zurich, Zurich, Switzerland

F. Schoth, MD, RWTH Aachen University Hospital, Aachen, Germany

F. Schwarz, MD, Department of Clinical Radiology, University of Munich, Campus Großhadern, Munich, Germany

H. Seifarth, MD, Department of Clinical Radiology, University Hospital, Münster, Germany

K. Takada, MD, Department of Radiology, Sakakibara Heart Institute, Tokyo, Japan

T. J. Vogl, MD, Department of Diagnostic and Interventional Radiology, Clinic of the Goethe Uni-versity, Frankfurt, Germany

P. Weisser, MD, Department of Diagnostic and In-terventional Radiology, Clinic of the Goethe University, Frankfurt, Germany

M. Wieser, MD, Clinic of Cardiovascular Surgery, University Hospital Zurich, Zurich, Switzerland

C. Wyss, MD, Cardiology Division, University Hospital Zurich, Zurich, Switzerland

Sameh Fahmy, freelance medical and technology journalist Tony DeLisa, freelance authorWiebke Kathmann, PhD, freelance scientific journalistHildegard Kaulen, PhD, freelance scientific journalistOliver Klaffke, freelance scientific journalistAnnette Tuffs, MD, medical journalist

Peter Aulbach; Karin Barthel; Andreas Blaha; Steven Bell; Ivo Driesser; Kerstin Fellenzer; Tomoko Fujihara; Jan Freund; Tanja Gassert; Toshihide Itoh; Christiane Koch, Rami Kusama; Marion Meusel; Jakub Mochon; Katharina Otani, PhD; Kerstin Putzer; Heike Theessen; Peter Seitz; Ste-fan Ulzheimer PhD; Fernando Vega-Higuera; Stefan Wünsch, PhD; all Siemens Healthcare

Photo Credits: Greg Morris, Yohanne Lamoulére/Agentur Focus, Harald Krieg, Thorsten Rother

Production: Norbert Moser, Siemens AG, Medical Solutions

Design and Editorial Consulting: Independent Medien-Design, Munich, GermanyIn cooperation with Primafila AG, Zurich, Switzerland; Managing Editor: Christa Löberbauer; Photo Editor: Susanne Nips; Layout: Claudia Diem, Mathias Frisch; All at: Widenmayerstraße 16, 80538 Munich, Germany

The drugs and doses mentioned herein are consistent with the approval labeling for uses and/or indications of the drug. The treating physician bears the sole responsibility for the diagnosis and treatment of patients, including drugs and doses prescribed in connection with such use. The Operating Instructions must always be strictly followed when operating the CT System. The sources for the technical data are the corresponding data sheets. Results may vary.Partial reproduction in printed form of individual contributions is permitted, pro-vided the customary bibliographical data such as author’s name and title of the contribution as well as year, issue number and pages of SOMATOM Sessions are named, but the editors request that two copies be sent to them. The written consent of the authors and publisher is required for the complete reprinting of an article.We welcome your questions and comments about the editorial content of SOMATOM Sessions. Manuscripts as well as suggestions, proposals and informa-tion are always welcome; they are carefully examined and submitted to the edito-rial board for attention. SOMATOM Sessions is not responsible for loss, damage, or any other injury to unsolicited manuscripts or other materials. We reserve the right to edit for clarity, accuracy, and space. Include your name, address, and phone number and send to the editors, address above.

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Publisher:Siemens AGHealthcare SectorBusiness Unit Computed TomographySiemensstraße 1, 91301 Forchheim, Germany

Monika Demuth, PhD ([email protected])

Stefan Wünsch, PhD([email protected])

SOMATOM Sessions · May 2010 · www.siemens.com/healthcare-magazine 77

Imprint

2 SOMATOM Sessions · May 2010 · www.siemens.com/healthcare-magazine

Editorial

“Our new neurological software combined with the SOMATOM Defi nition line of scanners repre-sents a quantum leap in speed, low dose and diagnostic accuracy.”

Sami Atiya, PhD, Chief Executive Officer, Business Unit Computed Tomography, Siemens Healthcare, Forchheim, Germany

Cover Page: With Volume Perfusion CT Neuro fused with carotid CT Angiography the perfusion status of the brain tissue can be observed. Courtesy of University Hospital Göttingen, Germany.

Chief Editors:

SOMATOM Sessions is also available on the internet: www.siemens.com/SOMATOMWorld


Editorial

Dear Reader, Imagine an emergency room only a few short years ago: in the middle of the night, a 55-year-old, unconscious patient is wheeled in. All neurologic observations indicate stroke. But how severe? Is it an occlusion or a hemorrhage and where is it located? All crucial questions that demand fast answers! The physician on duty could request a head CT examination that could possibly involve two scans at 15 to 30 mSv radiation dose. The physician would then begin with extensive post-processing – possibly using a PACS Workstation before the CT results could provide life the necessary clinical infor-mation required. Not a very pleasant alternative for the physicians or the patient.

Now imagine the same situation in a modern emergency room equipped with Siemens cutting-edge technology such as SOMATOM Definition Flash scanner – that scans faster than all other CT scanners on the market – with latest neuro imaging software and syngo.via software that “post-process on-the-fly” Within minutes, the physician would have access to the head scan results with all post-processing completed at lowest possible dose, including non-enhanced CT for exclusion of hemorrhage, com-plete vascular status plus functional information.

With syngo.via, Siemens’ new work-place software, all time consuming pre- and post-processing steps are eliminated and all diagnostic infor-mation – including information from other modalities such as MR, MI and PET – are available in almost real time. Best possible image quality is pro-vided with sophisticated “signal boost” technologies or image-optimizing techniques resulting in definitive grey and white tissue differentiation in neuro imaging. Excellent image quality and fast processes are bene-ficial for both physicians and patients as they are preconditions for highest diagnostic accuracy and, at the same time, low dose safety for the patient.

In all patient groups, including difficult obese and pediatric patients, as well as emergency room situations, safety is strongly linked to ALARA (As Low As Reasonably Achievable) radiation ex-posure. In the past, especially in acute clinical cases, lowering the radiation exposure when utilizing CT for diagnosis was not the primary focus. In stroke cases, “minutes equaled mind” and for accident victims, minutes could mean life or death. Today, thanks to Siemens’ significant leadership in bringing low dose CT into clinical routine, image quality is not necessarily tied to a slower diagnosis path and higher dose expo-

André Hartung, Vice President

Marketing and SalesBusiness Unit CT,

Siemens Healthcare

André Hartung


sure. CT is steadily moving into the first line of emergency and stroke imaging mainly because of the wide diagnostic spectrum, speed and diagnostic pre-cision. Providing all the advantages in CT imaging aligned with measures to minimize the radiation exposure has always been one of Siemens key goals. Therefore we have recently introduced new technical developments like IRIS to reduce radiation exposure to the lowest level in the CT industry. In functional imaging, e.g. for CT brain perfusion, the dose can be reduced by up to 50 % with 4D Noise Reduction, without compro-mising image quality. And our Adaptive Dose Shield completely eliminates pre- and post-spiral radiation that cannot be utilized for image reconstruction. These are only a few examples from dozens of additional large and small improvements developed by our dedicated employees to make the radiologist’s life easier and the patient’s healthcare better. You will find many of these reported in this, and in future editions of SOMATOM Sessions.

Good reading,Sincerely

* syngo.via can be used as a standalone device or together with a variety of syngo.via based software options, which are medical devices in their own rights..


Content

Cover Story

6 The Best of Both Worlds in Neuro Imaging

News

16 Affordable Performance in 16- and 64-slice CT

18 Best Balance Between Image Quality and Reduced Dose

19 IRIS Now Extended to SOMATOM Definition AS 20 and SOMATOM Definition AS 40

20 syngo CT 2010B Now Available: New Software Version for the SOMATOM Definition AS Launched

20 Worldwide Dose Counter 21 syngo.via Workstation Face-off

Sessions 22 syngo.via CT Speedometer 24 International CT Image Contest –

Highest Image Quality at Lowest Dose

Cover Story

Content

6 Exciting advances in computed tomography (CT) examination methods, including low dose protocols, technical innovations such as whole brain CT Perfusion, Dual Energy or Neuro Best Contrast applications and groundbreaking radiological research have drama-tically changed the diagnostic approach for reading physicians by enabling new indications and improved timing in the examination of patients with acute neurological deseases. SOMATOM Sessions discussed with five experienced physicians how CT can routinely be used as the key diagnostic modality in neuro imaging before the start of appropriate treatment.

24International CT Image Contest at Lowest Dose

6 The Best of Both Worlds

Somatom_26_Inhalt_INT.indd Abs2:4 07.05.10 10:10


Content

Oncology 46 3D Guided RF Ablation and CT

Perfusion – a New Combination for Monitoring of Treatment Response

48 SOMATOM Definition Flash: Routine Re-staging of Oesophageal Carcinoma Utilizing IRIS Technology

Neurology50 SOMATOM Definition AS+: CT Perfu-

sion With Extended Coverage for Acute Ischemic Stroke

52 Vasospasm After Subarachnoid Hemorrhage: Volume Perfusion CT Neuro

Acute Care 56 Dual Energy Scanning: Diagnosis

of Ruptured Cocaine Capsule 58 Progressive Kidney Hematoma

Post-interventional Biopsy 60 SOMATOM Definition Dual Source

High Pitch vs. Routine Pitch Scanning in a Pediatric Lung Low Dose Examination

Business

28 More for Less in Monaco 30 New Feature: Neuro Image Quality

Surpasses all Expectations

Clinical Results

Cardio-Vascular 32 Adenosine Myocardial Stress

Imaging Using SOMATOM Definition Flash

34 SOMATOM Definition Flash: Visualization of the Adamkiewicz Artery by IV-CTA in Dual Power Mode

36 Dynamic Myocardial Stress Perfusion 38 Pre-operative Exclusion of Coronary

Artery Stenosis With Less Than 1 mSv Dose

40 Utilizing Ultra Low Dose of 0.05 mSv for Premature Baby With Congenital Heart Disease

42 SOMATOM Definition Flash: Pediatric Patient Without Sedation and Breath-Holding

44 SOMATOM Definition Flash: Dual Energy Coronary CT Angiography for Evaluation of Chest Pain After RCA Revascularization

Science

62 CT in Pediatrics: Easier and Safer With the Flash

64 Study Finds Atherosclerosis in 3,500 Year old Egyptian Mummies

65 Independent Validation of Perfusion Evaluation Software

66 Reduced Procedure Time and Radia-tion Dose in Interventional CT Work-flow

68 Scientific Validation of the SOMATOM Definition Flash

Life

70 Behind the Scenes: CT Scan Protocols 72 First syngo.via Hands-on Workshops

at ECR 2010 72 Upcoming Events & Congresses 73 Training Website for Knowledge

Improvement 73 Free Trial Licenses for Neuro Imaging 74 Frequently Asked Questions 74 Dual Energy CT: Learning From the

Experts 75 Clinical Workshops 2010 76 Siemens Healthcare – Customer

Magazines 77 Imprint

64 Study Finds Atherosclerosis in 3,500 Year old Egyptian Mummies

– Highest Image Quality 52 Vasospasm After Subarachnoid Hemorrhage: Volume Perfusion CT Neuro


Coverstory




Coverstory

Exciting advances in computed tomo-graphy (CT) examination methods, in-cluding low dose protocols, technical innovations such as whole brain CT Perfusion, Neuro BestContrast or Dual Energy applications and groundbreaking radiological research have dramatically changed the diagnostic approach for reading physicians by enabling new indi-cations and improved timing in the ex-amination of patients with acute neuro-logical deseases. CT is routinely used as the key diagnostic modality in neuro imaging before the start of appropriate treatment to detect or exclude intracra-nial hemorrhage, either traumatic or non-traumatic, or to detect other causes of acute onset of neurological disease, such as stroke, intracerebral tumors, or hematoma. Rapid evaluation is critical after trauma and with symptoms such as weakness, headache, and dizziness, which is why CT is the modality of choice in these scenarios. Exceptional image quality is key to opti-mize diagnosis, and lower dose imaging helps to minimize the risk to the patient.It is often said that the price of improved image quality with CT is increased radia-tion dose, but Siemens has shown that high quality, low dose imaging is possi-ble in even the most challenging neuro-radiology applications. Whole brain CT

The Best of Both Worlds in Neuro ImagingExceptional Image Quality Meets Lowest Dose in Neuroradiology

At Duke University Medical Center in Durham, North Carolina, USA and elsewhere, Siemens equipment is helping radiologists combine exceptional image quality in neuro imaging with innovative dose-reducing features to maximize diagnostic confi dence.

By Sameh Fahmy

Perfusion imaging with Siemens’ unique Adaptive 4D Spiral and the use of CT Angiography from the aortic arch to the cranium are further expanding possibili-ties, increasing the diagnostic confidence of neurologists and potentially enabling more appropriate treatment decisions.“By providing really good image quality, we are able to improve the efficiency of care,” says David S. Enterline, MD, Asso-ciate Professor of Radiology and Division Chief of Neuroradiology at Duke Uni-versity Medical Center in Durham, North Carolina, USA. “And through dose sav-ings, we can minimize the risk to pa-tients.”

Neuro BestContrastAlthough newer techniques are revolu-tionizing stroke assessment, the gold standard for the initial diagnosis of stroke and intracranial hemorrhage is still non-contrast imaging of the brain. Siemens has always placed emphasis on providing the highest image quality on all of their scanners for this challenging application. Now, Siemens has taken image quality to the next level. Last year, Duke became the first hospital in the United States to install Siemens’ Neuro BestContrast, an application that dramatically increases gray/white matter differentiation in non-contrast head CT

“Neuro BestContrast allows radiologists to better visualize the gray/white mat-ter interface to see subtle edema and signs of stroke, and to better delineate the cortical margin.”

David S. Enterline, MD, Division Chief Neuroradiology, Duke University Medical Center in Durham, North Carolina, USA


“I think Neuro BestContrast and IRIS work perfectly with each other and have additive value in reducing dose.”Christoph Becker, MD, Professor of Radiology and Section Chief of CT and PET/CT

at Munich University Hospital, Munich, Germany

Coverstory


exams using the SOMATOM Definition line of scanners. Enterline says that Neuro BestContrast allows radiologists to better visualize subtle edemas as well as subtle signs of stroke, and to better delineate the cortical margin, adding, “My colleagues and I uniformly feel that with better image quality, our comfort level and our ability to make diagnoses are significantly increased.” The improved image quality experienced by Enterline and his colleagues at Duke is also evidenced by clinical data and the

experience of radiologists in Europe. In a blinded study whose results were pre-sented at the 2009 scientific assembly and annual meeting of the Radiological Society of North America, neuroradiolo-gists preferred Neuro BestContrast data sets in 97 % of cases.1 Other readers, who viewed the Neuro BestContrast data set side-by-side with the traditional images, also rated image quality better in more than 90 % of the cases and lesion conspicuity higher in more than 50 % of the cases.

1A 1B 1C

1 Comparing conventional head CT imaging (Fig. 1A) with the new IRIS technology (Fig. 1B) shows decreased image noise. Combining IRIS with Neuro BestContrast technology provides very high image quality with decreased noise by utilizing reduced radiation dose (Fig. 1C).

At the University Hospital in Göttingen, Germany, Peter Schramm, MD, Deputy Head of the Department of Neuro-radiology, was able to compare images acquired before and after the implemen-tation of Neuro BestContrast in a patient with head trauma whose hospitalization coincided with the hospital’s transition to the new software. “We were able to perform an exact comparison intra-individually, and in that case it was really impressive to see the improvement that came along with Neuro BestContrast,”



Coverstory

Schramm says. “The delineation of the edema and the margins of the edema were definitely better visualized using Neuro BestContrast, and the same ap-plies to the changes that occur in acute stroke.”Neuro BestContrast improves non-con-trast head images by taking advantage of the fact that clinically important infor-mation from CT scans is contained in me-dium and low frequencies, while high fre-quencies are dominated by image noise. The software processes high-frequency data differently than the low-to-medium frequency data, resulting in improved tissue contrast without the amplification of image noise.Enterline says the use of Neuro BestCon-trast has the potential to reduce radiation dose as well. His preliminary data has documented a 15 to 20 % improvement in gray/white matter differentiation that can allow for image acquisition at a lower dose than is currently used. “Our institu-tion has traditionally fought for lower dose,” he says, “and I think this will now allow us to further reduce our dose.”

IRISNeuro BestContrast can be combined with another new Siemens technology known as Iterative Reconstruction in Image Space (IRIS) to reduce dose and improve image quality even further. “I think they work perfectly with each other and have additive value,” says Christoph Becker, MD, Professor of Radi-ology and Section Chief of Computed Tomography and PET/CT at Ludwig-Maxi-milians-University in Munich, Germany.Iterative reconstruction uses a correction loop to improve image quality in several steps, or iterations. The idea was first introduced in the 1970s, but the com-puting power and time required for the reconstruction made it impractical for use in clinical settings. An alternative known as statistical image reconstruction reduced the time associated with itera-tive reconstruction but produced a tex-ture that radiologists found unaccept-able. With IRIS, Siemens took a different approach. The algorithm takes all of the data, which contains fine details as well as significant amounts of noise, com-

of dense structures such as bone and calcium, making it easier to visualize or rule out subarachnoid hemorrhage. Preliminary data from Becker show that IRIS reduces dose by 25 % in head CT exams yet achieves the same level of noise as filtered back projection, the tra-ditional method for image reconstruc-tion. Becker notes that clinicians can also choose to use the same dose as fil-tered back projection yet deliver signifi-cantly better image quality using IRIS.In the United States, Ridgeview Medical

bines it in a master image and cleans it up in the fast-processing image space rather than in the slow-processing raw data area. The result is that high spatial resolution is preserved and noise is re-duced – without disrupting workflow.Becker says the combination of Neuro BestContrast and IRIS, which is available on the SOMATOM Definition line of scanners, allows him and his colleagues to better differentiate the basal ganglia and to see subtle signs of stroke. He adds that IRIS also reduces the blooming

Iterative Reconstruction in Image Space (IRIS)

Strong artifact and dose reductionWell-established image impressionFast reconstruction in image space

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Image data Image data reconrecon

Image correction

2 IRIS takes all of the data, which contains fine details as well as significant amounts of noise, combines it in a master image and cleans it up in the fast-processing image space rather than in the slow-processing raw data area. The result is that that high spatial resolu-tion is preserved and noise is reduced – without disrupting workflow.

2


“With the improve-ment in radiation dose using IRIS, the image quality is not changed, so we just switched right over to it.”

David Gross, MD, Chief of Radiology

Ridgeview Medical Center, Waconia,

Minnesota, USA

Coverstory


Center in Waconia, Minnesota, USA in-stalled IRIS on its SOMATOM Definition AS 40-slice CT and its Definition AS+ 128-slice scanner early in 2010. Chief of Radiology, David Gross, MD, directly compared images produced using IRIS with traditional filtered back projection images and then enthusiastically adopt-ed IRIS. “After two or three days, we decided that there’s no sense in even comparing anymore,” Gross says. “With the improvement in radiation dose, the image quality is not changed, so we just switched right over to it.”Neuro BestContrast and IRIS build upon other Siemens innovations in neuro imaging that maximize diagnostic confi-dence. The “Posterior Fossa Optimization” algorithm, which was introduced in 2001 and is implemented in all SOMATOM Sensation and Definition scanners, significantly reduces streaks and dark bands, known as Hounsfield Bars, to allow for better resolution with less artifact. Siemens’ z-Sharp Technology provides routine isotropic resolution of 0.33 mm, one of the industry’s highest, enabling the visualization of small anatomical details such as fine vascular structures. For ultra-high-resolution bone imaging for inner ear structures, Siemens’ z-UHR Technology provides 0.24 isotro-pic resolution.

Perfusion CT and CTAWhile non-contrast head CT exams are still important for excluding intracranial

“Dynamic CT Perfusion imaging, which can be acquired immediately after the non-contrast head CT while the patient is still in the scanner, allows improved detection of acute stroke, which has been substantiated in several studies.”2, 4

Ke Lin, MD, Assistant Professor of Radiology, Department of Radiology, New York University

Langone Medical Center, New York, USA

hemorrhage and ischemic stroke mimics, the use of perfusion CT imaging is in-creasingly being adopted. “Dynamic CT Perfusion imaging, which can be acquired immediately after the non-contrast head

CT while the patient is still in the scanner, allows improved detection of acute stroke, which has been substantiated in several studies,” says Ke Lin, MD, Assis-tant Professor of Radiology at New York University Langone Medical Center in New York City, USA. In a study of 100 patients presenting to the emergency department within three hours of stroke onset, Lin and his colleagues found that CT Perfusion provided significantly im-proved sensitivity and accuracy in acute stroke detection over non-contrast CT. Specifically, the researchers found that CT Perfusion revealed 64.6% of acute infarctions compared to 26.2 % for non-contrast CT. CT Perfusion also had an ac-curacy of 76 % compared to an accuracy of 52 % for non-contrast CT.2

Lin and his colleagues obtained CT Per-fusion data from a z-direction coverage of 24 mm centered at the mid-basal ganglia which maximizes the visualiza-tion of the middle cerebral artery terri-tory. Still, the researchers noted that they missed ten infarcts that were out-side of this volume of coverage. The ad-vent of whole brain CT Perfusion using Siemens’ unique Adaptive 4D Spiral, how-ever, further increases the value of CT Perfusion by expanding the scan range. The revolutionary scan mode, which is available on the SOMATOM Definition line of scanners, overcomes the limita-tions of a static detector design by ap-plying a continuously repeated bi-direc-tional table movement that smoothly



3 Perfusion CT imaging is in-creasingly be-ing adopted in daily routine. This function overcomes the limitations of a static detector design, which provides full brain coverage, and the poten-tial for improve-ment in diag-nostic accuracy for acute stroke.

3

Coverstory

a smooth, fast, and user-friendly work-flow. A number of steps are automated, including motion correction, bone seg-mentation, arterial input function deter-mination, and vascular pixel elimination. The software allows for simultaneous visualization of functional parametric maps of cerebral blood flow, cerebral blood volume, time to peak, mean tran-sit time and other clinically important information. With the click of a button, clinicians can toggle between axial, sagittal and coronal reformations.Lin and his colleagues acquire the CT Perfusion data for the whole brain in just 45 seconds. Next, CT Angiography data from the aortic arch through the whole brain, a scan range of typically more than 30 cm, is acquired in a couple of seconds to deliver valuable infor-mation about the feeding vessels that are not covered by the initial perfusion scan. Post-processing takes an additional three to five minutes. In total, when time for interpretation is accounted for, the use of CT Perfusion and CT Angio-

moves the patient in and out of the gantry over the desired scan range. Lin has recently switched to a SOMATOM Definition AS+ Scanner with all the advantages of full brain coverage. “With the increased coverage, we now expect further improvement in acute stroke detection accuracy, as well as the full delineation of the ischemic penumbra and the infarct core,” Lin says.The stroke imaging workflow at NYU Langone Medical Center also includes a CT Angiography immediately following the CT Perfusion exam to evaluate clot location, clot burden, and collateral re-cruitment. Lin adds that the information is also used for planning interventional procedures such as mechanical throm-bectomy.Lin says the fast image acquisition of the SOMATOM Definition AS+ 128-slice scanner, combined with the rapid post-processing of the Siemens syngo Volume Perfusion CT Neuro software, allows reading physicians to arrive quickly at an appropriate treatment decision through

graphy adds approximately 10 minutes to the acute stroke workflow. “That’s not a lot of time considering that the addi-tional information provided by the CT Perfusion and the CT Angiography may have very important implications for the patient’s treatment and management,” Lin says.

Reducing Dose in CT PerfusionLin recognizes that, while the use of CT Perfusion is moving from academic medical centers to community hospitals, some barriers to its widespread adoption remain. Chief among them is a concern about the radiation dose associated with the acquisition of CT Perfusion and CT Angiography data. The use of Siemens 4D Noise Reduction, however, can re-duce the radiation noise of dynamic CT Perfusion. The reconstruction technique treats the static anatomical information differently from the dynamically chang-ing perfusion information that results from the in and outflow of the contrast agent. By sampling multiple passes over


Coverstory


4 With Volume Perfusion CT (VPCT) fused with carotid CTA the perfusion status of the brain tissue can be re-vealed. This patient presented after onset of stroke and underwent lysis therapy. The follow-up examination showed a complete revascularization of the previously hypoperfused area.Courtesy of Uni-versity Hospital Göt-tingen, Germany.

the same volume it allows for the reduc-tion of image noise. So the initial scan can be performed with a lower tube current, thus saving dose. The result is that radiation dose is reduced by up to 50 % while retaining equivalent diagnostic information. Although such dose-saving features can benefit patients, Lin cautions that the issue of dose must be kept in context during an acute stroke. “The acute criti-cal ischemic event that could kill the patient takes priority over the slight in-crease in radiation dose that is imparted to the patient in order to arrive at a more accurate diagnosis, a clearer understanding of the patient’s patho-physiology, and a broader understand-ing of the acute event,” he emphasizes.Lin points out that only 2 % of acute stroke patients receive intravenous tissue plasminogen activator (tPA), the only U.S. Food and Drug Administration approved drug for acute stroke. He says this low rate is largely because of the restrictive three-hour time window in which the drug is approved for use. An additional factor is that an unknown time of onset, which occurs in up to 25 % of acute stroke patients, disqualifies patients from receiving the drug.In Europe, the University of Göttingen, Germany has established stroke units where patients are examined in an elon-gated time window of 4.5 hours after the onset of stroke, based on results from the Third European Cooperative Acute Stroke Study3 (ECASS III), so that more patients can benefit from tPA treatment.Rather than making treatment decisions based on the clock, the use of perfusion CT and CT Angiography can help deliver truly personalized medicine for acute stroke patients. The adage “time is brain” still applies, Lin says, but technology can enable a new paradigm that says that “physiology is brain.”“The rallying cry of ‘physiology is brain’ is really a summation of the proposal to use a patient’s own pathophysiology, his own cerebral hemodynamics, to deter-mine whether he still has significant amounts of salvageable tissue at risk and therefore should be a candidate for acute stroke therapy within the confines

5 With Dual Energy (DE) Bone Removal vascular structures can quickly be sepa-rated from the bones even in difficult areas such as the base of the skull. This clearly proves the clinical benefit of DE for clinical routine. Courtesy of University Hospital Munich, Campus Großhadern, Germany.

4

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Coverstory

“We were able to perform an exact com-parison intra-individually, and in that case it was really impressive to see the improvement that came along with Neuro BestContrast.”

Peter Schramm, MD, Deputy Head of the Department of Neuroradiology,

University of Göttingen, Germany

of the safety profile of the various treat-ments,” Lin says.

A Range of Neuro Imaging OptionsOf course, the use of CT in neuroradio-logy is not limited to patients with acute stroke. syngo Volume Perfusion CT Neuro software provides a rapid and automated evaluation of brain tumors that enhances the ability to grade tumors, plan biopsies, and monitor therapy. The use of MRI to image brain tumors is well established, but Schramm notes that the use of CT Perfusion can be advantageous in some cases. Intra-cerebral lymphomas, for instance, can be difficult to differentiate using MRI but can be easily identified using perfusion CT. “My prognosis is that CT will gain even more ground in the coming years, and this is due to the fact that it is broadly available, less expensive than MRI, and, in many cases, offers better spatial resolution,” he says. Another tool that significantly improves workflow and diagnostic confidence in the assessment of vascular structures of the head and neck is syngo.via* CT Neuro DSA (Digital Subtraction Angio-graphy), which automates the removal of bone from images, even in difficult areas such as the base of the skull. The very robust technique uses a non-con-trast, low-dose scan that is acquired be-fore the actual CT Angiography and is then used to automatically remove all the bone structures in the scanned re-gion. On Dual Source CT scanners such

as the SOMATOM Definition and Definition Flash “syngo Dual Energy Direct Angio” offers a similar technique which permits direct removal of bone using only one scan. It uses the fact that two X-ray sources running simulta-

neously at different energies can acquire two data sets with different attenuation levels.“DSA is susceptible to any motion that occurs between the exams,” Becker points out, “whereas with Dual Energy there are never any motion artifacts when we extract the bone from the dataset.” The scan speed of up to 45,8 cm per second and the temporal resolution of 75 milliseconds that is possible with the SOMATOM Definition Flash can be particularly helpful in scanning the carotid arteries, Becker says, since they quickly fill with contrast media. He says the high-pitch Flash mode makes it easy to accurately time the scan so that pure arterial phase can be achieved without venous overlay that can impair visualization. Additionally, the information from dynamic CTAs using the Adaptive 4D Spiral technology offers new insights in cerebral hemo-dynamics to evaluate endoleaks, Takayasu disease, or complex hemodynamics of dural arteriovenous fistula. Becker adds that Siemens’ latest imaging software, syngo.via*, speeds workflow by allowing him and his colleagues to access and share data from anywhere** within the network.

As Low as Reasonably Achievable“In developing advances that aim to im-prove the diagnostic confidence of phy-sicians and patient outcomes, Siemens is committed to reducing radiation dose to the lowest possible level following the

“Siemens is commit-ted to reducing radiation dose to the lowest possible level. Innovations such as IRIS are evidence of this commitment as is X-CARE”

Sami Atiya, PhD, Chief Executive

Officer, Business Unit Computed

Tomography, Siemens Healthcare,

Forchheim, Germany.

syngo.via can be used as a standalone device or together with a variety of syngo.via based software options, which are medical devices in their own rights.Prerequisites include: internet connection to clinical network, DICOM compliance, meeting of minimum hardware requirements, and adherence to local data security regulations.

***

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4D NoiseReduction

Up to 50 % dose reduction

2008

Adaptive Dose Shield


2007

Selective Photon Shield

No dose penalty

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80 kVAttenuation B

Selective Photon Shield

Dose Shield

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7 Siemens has been a pioneer in creating a host of innovative technical features that significantly reduce radiation exposure in CT scans. Using these features may result in variant values of dose reduction.


6 X-CARE is especially important in CT for protecting dose sensitive tissue, e.g. the lenses of the eyes (Fig. 6A). To further reduce the radiation dose for the lenses, additional safety devices like an eye protector (Fig. 6B) can be used.

6A 6B

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Iterative Reconstruction in Image Space (IRIS)


2009

Neuro BestContrast

oUp t 30 % dose reduction

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o

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1 Diehn F, et al. – RSNA 2009 presentation SSE23-

03: A Preliminary Study of Novel Post-processing

Tool: Multi-Band Filtration of Noncontrast Head

CTs.

2 Lin K, et. al. – Cerebrovascular Diseases 2009;

28:72-79

3 Hacke W, et al. – NEJM 2008;359 (13) 1317-1329

4 Thomandl B, et al. – RadioGraphics, 23:565-592

‘as low as reasonably achievable’ (ALARA) principle. Innovations such as IRIS are evidence of this commitment, as is Siemens X-CARE”, says Sami Atiya, PhD, Chief Executive Officer, Business Unit Computed Tomography, Siemens Healthcare in Forchheim, Germany. The application protects sensitive organs by lowering the tube current during the portion of the rotation in which the area of concern would otherwise be near the X-ray source. Enterline, at Duke University Medical Center in Durham, USA, points out that X-CARE is especially important for protecting the lenses of the eyes, which are particularly radiosensitive. He says the technology has allowed him and his colleagues to reduce dose to the lens up to 30 % in preliminary data without a reduction in image quality. They routinely use X-CARE in their practice.Another technology that minimizes dose to patients is the Siemens Adaptive Dose Shield, available on the SOMATOM

Definition AS and Definition Flash scan-ners. With traditional spiral CT exams, patients are exposed to unnecessary radiation at the beginning and the end of the exam. The Adaptive Dose Shield automatically moves collimators into place to block this unnecessary exposure, thereby reducing dose by up to 25 %. Becker notes that the proportion of over-beaming is especially significant over small scan ranges, so pediatric patients and those requiring head CT exams stand to gain the most.Becker and his colleagues further reduce radiation dose with Siemens CARE Dose4D, which provides real-time mo-dulation of dose, based on patient size and the anatomy being imaged. “I totally insist on using it,” Becker says. “We don’t switch this option on and off – we use it for every CT scan.”Concerns about radiation dose have moved from the medical journals and conference halls into the mainstream

news media. Enterline and others say that, as a result, patients increasingly ask about the potential consequences of their exposure to medical imaging. Discussing the risks and benefits asso-ciated with CT imaging with patients helps reassure them, Enterline says, and so does having technology that minimizes dose. “It’s our responsibility to do what we can to minimize dose and to make sure that the studies are appropriate,” he adds. “It’s the right thing to do for patients.”

Sameh Fahmy is an award-winning freelance medical and technology journalist based in Athens, Georgia, USA



News

Affordable Performance in 16- and 64-slice CTAt the European Congress of Radiology in March 2010, Siemens introduced new 16- and 64-slice systems to the market: The SOMATOM Emotion Excel Edition and the SOMATOM Defi nition AS Excel Edition.

By Jan Freund, Steven Bell and Rami Kusama, Business Unit CT, Siemens Healthcare, Forchheim, Germany

The new Excel Editions from Siemens are especially cost-effective versions of the SOMATOM Emotion 16-slice and SOMATOM Definition AS 64-slice scan-ners. The Excel Edition is the result of Siemens’ commitment to developments that bring new technology to more people through reducing the costs of these innovations. These new additions to the Emotion and Definition AS fami-lies offer customers access to 16-slice and 64-slice Siemens technology in scanners that include many of the ad-vantages that existing Emotion and Definition AS customers know, at a significantly more advantageous price.On the one side, the SOMATOM Emotion Excel Edition is especially designed to make it easier for small and medium-sized hospitals and practices to enter the world of 16-slice computed tomography. It continues the success story of the Emotion platform that remains the most popular CT in the world. The success of the SOMATOM Emotion platform to date has been due to superb image quality, a simplified and efficient workflow, and the ability to save money over the life of the CT system. To date, there are around 7000 systems installed worldwide. The 16-slice SOMATOM Emotion Excel Edition builds on the prior success of this imaging platform to bring these advantages to more customers and patients. It offers the smallest focal-spot size and a high number of effective

The new Excel Editions from Siemens are especially affordable versions of the SOMATOM Emotion 16-slice and SOMATOM Definition AS 64-slice scanners.



News

www.siemens.com/somatom-emotion

www.siemens.com/somatom-definition-as

detector channels for increased image clarity and resolution. It continues Siemens’ focus on dose reduction with the exclusive CARE Dose4D algorithm offering dose reduction of up to 68 % in routine scanning. Customers will also continue to benefit from the easy-to-use syngo user interface that Siemens customers across all imaging modalities are familiar with. On the other side, the SOMATOM Definition AS Excel Edition introduces a high-end, yet affordable 64-slice work-horse for both everyday clinical routine and advanced imaging. It will broaden the portfolio of the SOMATOM Definition AS family and continue its legacy as the world´s first adaptive scanner. Its unique-

ness is the unprecedented adaptability to any patient and any clinical question, making it an expert in virtually any clinical field. With the introduction of the SOMATOM Definition AS Excel Edition, Siemens continues to lead the world of innovation by making two ends meet: bring outstanding imaging tech-nology and advanced clinical applica-tions to budget-minded customers.The SOMATOM Definition AS Excel Edition addresses the growing market for entry-level 64-slice scanners. Especially this segment is currently facing a very strong trend towards commoditization, demanding a reliable, cost-efficient 64-slice system to realize high through-put in everyday clinical routine. For this,

the scanner offers the highest degree of flexibility with its 78 cm gantry and a table load capacity of up to 300 kg thus avoiding delays and patient exclusions.Combined with the industry’s highest sub-mm resolution and coverage speed in its segement, a rotation speed of 0.33 seconds and unique applications like 3D-guided CT interventions, the SOMATOM Definition AS Excel Edition delivers state-of-the-art CT imaging and can cope with literally every need in clinical routine. At the same time, it sets stan-dards in patient safety by providing a unique composition of dose protection features like CARE Dose4D, the innova-tive Adaptive Dose Shield, which avoidsunnecessary overradition in every spiral scan, or IRIS – the Iterative Reconstruc-tion in Image Space which allows a dose reduction of up to 60 %. With its onsite upgradeability to the standard AS 64-slice and AS+ 128-slice configura-tions and with the smallest footprint in its segment, the new Edition is the ideal system for customers that are both performance and budget-minded.Finally, together with syngo.via* – Siemens’ new imaging software – the SOMATOM Definition AS Excel Edition grants access to a whole new world of workflow improvement. By moving from post-processing of image data to having it pre-processed and ready to review, it sets new standards in ease-of-use and thus clinical efficiency. The SOMATOM Emotion Excel Edition was released on the first of April 2010 and the SOMATOM Definition AS Excel Edition on the first of May. For more information about the new Excel Editions, the local Siemens representative can be contacted.

* syngo.via can be used as a standalone device or together with a variety of syngo.via based software options, which are medical devices in their own rights.


Best Balance Between Image Quality and Reduced DoseIterative Reconstruction in Image Space (IRIS) provides individual choices and benefi ts for all patients.

By Annette Tuffs, MD

It is a difficult choice for physicians to decide what benefits the patient most, the highest resolution with best image quality and diagnostic confidence – or the lowest radiation level to reduce the long-term risks for their patients.Modern CT technology like IRIS cannot entirely overcome this dilemma, of course, but it provides flexible solutions that allow choices for the individual patient according to age, condition, suspected pathology and the specific CT investigation being performed, thereby permitting the reading physician to carefully weigh the benefits of highest possible resolution against the advan-tages of minimized radiation exposure.

IRIS – A Success StoryThe peak of these impressive develop-ments is IRIS, which stands for Iterative Reconstruction in Image Space. It had its debut at the 2009 RSNA meeting in Chicago and has proven to be another Siemens success story in substantially reducing radiation dose. It is based upon “iterative reconstruction,” a method first developed in the 1970s to reduce noise in CT images. Iterative reconstruction includes a “cor-rection loop,” in which images are repeat-edly calculated by assumptions. The image becomes softer in homogenous tissue regions while, at the same time, high-contrast tissue boundaries are main-tained. Image resolution and image noise are no longer closely inter-dependant. However, this process required a lot of

time and enormous computing capacity and therefore – before IRIS – was not feasible for use in clinical routine. Now, Siemens engineers and scientists have optimized the process and developed IRIS, where time and computing capacity are no longer an issue.“We are enthusiastic about this innova-tive method in CT scanning, that´s why we use it in our greatly improved daily routine,” says Professor Joseph Schoepf, MD, whose Department of Radiology at the Medical University of South Carolina, Charleston, USA, was one of the first to gain clinical experience with IRIS. His department has been using IRIS on a routine basis since autumn 2009 for about 15 patients per day.

All Patients Benefi tSeveral university hospitals, in Germany and abroad, have already been able to gather extensive clinical experience with IRIS. One of them is the University Hospital, Erlangen in Germany, where Michael Lell, MD, Senior Physician at the Radiology Institute, has been involved in studies concerning the potential of IRIS in reducing radiation dosage. In one of his studies, that he will submit for publica-tion in the next months, more than 70 patients have been evaluated with and without IRIS. The radiologists in Erlangen were looking specifically at the abdo-men. “As a preliminary result, we can say that we were able to achieve a 50 % dosage reduction while maintaining high standards of image quality,” Lell

recounts. Which patients will benefit most from the use of IRIS? “All patients should have the benefit,” says Lell, “and therefore we changed all our protocols to include IRIS.” However, there are spe-cific patient groups that should benefit even more, for instance children, since they demand the smallest possible dose because of long-term, higher potential radiation risks and, at the same time, have smaller body structures, which are more difficult to visualize in CT scanning procedures. Lell specifically mentions the group of children and juvenile patients with muco-viscidosis, an unstable condition that can require frequent CT scans. He is optimistic that, with the ongoing fine-tuning of IRIS, further dose reductions will be possible and he is confident that the magic thresh-old of up to 70 % reductions can be reached.

Special Object: Cardiovascular StentAnother group of patients that especially benefit from IRIS is the increasing num-ber of obese patients of both genders and all ages. Even when the smaller of these morbidly obese patients are able to squeeze through the CT gantries, the resulting images are often substandard, sometimes strikingly so. “The diagnostic results can be greatly improved with IRIS in obese patients,” says Schoepf. His hospital mainly cares for patients with either digestive disease or cardiovascular disease. His special

1 Since autumn 2009 in the University Hospitals Munich and Erlangen-Nuremberg all CT scan protocols have been changed to use IRIS in clinical routine.


News

1


Because at Siemens dose reduction has continued to be given top priority, assur-ing both patients and medical personnel the best in medical care with the least possible risk, the availiability of IRIS with the SOMATOM Definition, SOMATOM Definition Flash, and SOMATOM Definition AS+ and AS 64, will be ex-tended to the SOMATOM Definition AS 40, as well as AS 20. Now all scanners from the SOMATOM Definition family* will benefit from excellent diagnostic image quality with levels of dose lower than ever before. With IRIS, Siemens’ smart approach to iterative reconstruc-tion, up to 60% additional dose reduction can be achieved in a wide range of daily routine CT applications.Dose reduction with CT has been limited by the currently used filtered back projec-tion reconstruction algorithm. When using this conventional reconstruction of acquired raw data, a trade-off between spatial resolution and image noise has to be considered. Higher spatial resolution

IRIS Now Extended to SOMATOM Defi nition AS 20 and SOMATOM Defi nition AS 40By Rami Kusama, Business Unit CT, Siemens Healthcare, Forchheim, Germany

increases the ability to see the smallest detail; however, it is directly correlated with increased image noise. In an iterative reconstruction, a correc-tion loop is introduced into the image generation process. To avoid long recon-struction times, IRIS first applies a raw data reconstruction only once. During this initial raw data reconstruction, a so-called and newly developed master volume is generated that contains the full amount of raw data information, but at the expense of significant image noise. During the following iterative correc-tions, the image noise is removed with-out degrading image sharpness. The new technique results in increased im-age quality or dose savings of up to 60 % for a wide range of clinical applications.90 day, free trial licenses for IRIS are now also available. The local sales representative can be contacted for details.

*requires syngo CT 2010A or syngo CT 2010B

Up to 60 % dose reduction Image quality improvement Fast recon in image space Well-established image impression 90 day, free trial license

interest is testing IRIS in patients with heart stents that are supposed to keep the coronary arteries open.“Coronary stents are the Achilles’ heels of radiological heart diagnostics,” says Schoepf. With IRIS, it is easier to detect whether there is a true obliteration of the stent or the so-called, “beam harden-ing,” that only simulates closure of the stent. Preliminary results of a study at the Medical University of South Carolina have already shown that IRIS will help to make this important distinction, that has a major impact on therapeutic deci-sions and results.

Searching for Small Liver MetastasesAnother important area with far-reaching therapeutic consequences is the imaging

of the liver, especially when searching for small metastases of malignant tumors elsewhere in the body. “With IRIS, we have a much better chance of finding these lesions,” says Schoepf.Konstantin Nikolaou, MD, Prof. of Radiology, Associate Chair of the Depart-ment of Radiology, Munich University Hospital, Germany, also agrees that all patients can profit from the use of IRIS, some of them more than others. Since last autumn, he and his colleagues have changed all the protocols to use IRIS. By April 2010, more than 3.000 patients of all ages and conditions profited from improved IRIS image quality or dose reduction. Overall dose reductions in all body regions of about 30 % were achieved, and current scientific studies at the University of Munich are designed

to prove this effect. “IRIS has improved our daily routine because of higher im-age quality or lower dose.” The Munich radiologists are currently running studies where the diagnostic results from IRIS images are compared with conventional images, and their recent finding have shown that an experienced radiologist can easily adjust to the new kind of image impressions. “A trained eye can benefit from the IRIS specific images – the improved spatial image resolution in high contrast areas, with less noise in the low contrast areas.”

Annette Tuffs, MD, is a medical journalist based in Heidelberg, Germany. The former medical editor of the daily Die Welt has been contributing to the Lancet and the British Medical Journal since 1990.

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Iterative Reconstuction in Image Space (IRIS)

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syngo CT 2010B Now Available: New Software Version for the SOMATOM Defi nition AS LaunchedBy Jan Freund, Business Unit CT, Siemens Healthcare, Forchheim, Germany

The new syngo software version, CT 2010B, for SOMATOM Definition AS scanners, was released in April 2010. It makes IRIS (Iterative Reconstruction in Image Space) available to SOMATOM Definition AS customers. With IRIS, a

dose reduction of up to 60% is possible without compromising image quality. In addition, native head-image quality can be significantly improved with Neuro BestContrast without an increase in dose. By separating low and high fre-

quency data, it specificly optimizes the tissue contrast without amplifying the image noise, resulting in an improve-ment of signal to noise ratio of up to 30 %. In dynamic studies, such as CT Perfusion images, noise can be signifi-cantly reduced. As a result, radiation dose can be lowered without compro-mising image quality. The Adaptive Signal Boost optimizes lower signals, e.g. when low dose or obese protocols are used. Neuro BestContrast, 4D Noise Reduction and the Adaptive Signal Boost will be available free of charge. CARE Contrast II synchronizes CT scan and contrast media injection. With its open interface technology, it is ready for future applications. The syngo CT 2010B will be delivered with all new systems beginning in May 2010 and as a field roll-out to the complete installed base of the SOMATOM Definition AS.

With the SOMATOM Definition Flash, coronary CTAs become routinely available at dose levels below 1 mSv. Now every-body can check dose values for them-selves, in daily routine, worldwide, and in almost real-time. Being able to image the coronary arteries with a radiation dose of below 1 mSv is impressive in itself, but it becomes even more impressive when this happens everyday, all around the globe and not just in a few specialized cases. That’s why Siemens decided to make av-erage doses of Flash Spiral Cardio scans –

Worldwide Dose CounterBy Peter Seitz, Business Unit CT, Siemens Healthcare, Forchheim, Germany

www.siemens.com/low-dose

View on the Siemens Healthcare dose counter homepage.

analysis that is sent from SOMATOM Definition Flash installations worldwide. In addition latest news and further infor-mation are available on Siemens Low Dose CT.

our all-new high-pitch mode for scan speeds up to 458 mm/s – publicly avail-able. With this ultrafast scanning, the SOMATOM Definition Flash acquires the entire heart in only around 270 ms, re-ducing radiation exposure to the mini-mum, all the while maintaining the excel-lent image quality that previously was only possible at much higher dose levels. At www.siemens.com/low-dose anyone can observe the current average dose on the installed base. This value is updated every 30 minutes by statistical data

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News

syngo.via Workstation Face-off SessionsBy Karin Barthel, Business Unit CT, Siemens Healthcare, Forchheim, Germany

At RSNA 2009, Siemens Healthcare introduced their new imaging software, syngo.via,* a client-server based soft-ware solution which allows to display most used applications across various im-aging modalities – dedicated not only to general radiology but tailored to specific clinical fields such as oncology, neurology, vascular imaging and cardiology as well. Since then, syngo.via has participated at 2 major face-offs. At a face-off, several industry vendors enter the arena to dem-onstrate cases live on their respective workplaces, permitting the audience to make an immediate, direct comparison of the software versions and results.First, syngo.via met the challenge at the 6th International MDCT Symposium 2010 in Garmisch-Partenkirchen, Germany, where about 1.600 CT experts were reg-istered. Thomas Mang, MD, from the Uni-versity Hospital in Vienna demonstrated the cases for Siemens. The first was a vascular case where an aneurysm needed to be evaluated. With syngo.via, Mang could fulfill all tasks ahead of time in out-standing clinical quality. Only 2 minutes were required since many steps, like table removal, bone removal, naming of vessels, curved MPRs and orthogonal views, were automatically calculated by syngo.CT Vascular Analysis.** The second case was an oncology case in which multiple liver lesions had to be measured. The auto-matic synchronization of datasets, the propagation of previous results and the unique Findings Navigator helped to speed up the workflow tremendously. The contouring algorithm worked per-fectly and measured reliably, even for the very complex liver lesions that, in compari-son to the surrounding tissue, showed very similar density.

The second competition was the work-station face-off at the ECR in March 2010 in Vienna, Austria. There, 3 cases where demonstrated by Marco Das, MD, from the University Hospital in Maastricht, The Netherlands. The first case was a vascular case whereby a high-grade stenosis in the common carotid artery needed to be quantified and an occlusion in the MCA segment had to be displayed. The case was completed with syngo.via with only a few steps. Due to all the automated tools, Das only had to click into the areas of interest and could show the results. The second case was a brain perfusion in which the MTT, CBF and CBV parameters had to be measured. Here it was only necessary to open the syngo Volume Perfusion CT Neuro application to accept the results and to place a ROI into the in-farction. Everything else was automati-cally calculated by the system. All in all, this took only 45 seconds.The third case was a PET/CT case in which the assessment of response to treatment between 3 time-points had to be done with an volumetric assessment according to RECIST, WHO and volume, including percentual change between examina-tions as well as an metabolic SUV assess-ment based on PET data. With the Find-ings Navigator it was very simple to jump from finding to finding. And the compari-son of findings was easy to use since all images such as CT, PET, Fused and MIP images were displayed next to each other. Due to the dedicated lung, liver and lymph algorithms, all kinds of le-sions, no matter if large or small were contoured and measured precisely. These results showed that syngo.via currently will be an industry standard for state-of-the-art imaging solution.

With syngo.via, a vascular case, demonstrated during the face-off in Vienna, was completed with only a few steps due to automated tools.

“I saw the syngo.via face-off in Garmisch and was very impressed. So, when I was asked to demonstrate it in Vienna, I agreed immediately. Although the software was new for me, it was easy to learn and I was proud to demonstrate it at the ECR.”

Marco Das, MD, Maastricht University Medical Center, The Netherlands

“Due to the automated features within syngo.via, manual preparation of cases is no longer necessary. Now, a radiologist can start working where he wants to start, with reading the case.”

Thomas Mang, MD, AKH, Vienna, Austria

syngo.via can be used as a standalone device or together with a variety of syngo.via based software options, which are medical devices in their own rights.The information about this product is being provided for planning purposes. The product is pending 510 (k) review, and is not yet commercially available in the U.S.

***


News

syngo.via CT SpeedometerIn November 2009, Siemens Healthcare introduced syngo.via, a new client-server based imaging solution concept to improve quality of patient care, to cut costs for healthcare and to help hospitals and practices optimize their workfl ows.

By Karin Barthel, Business Unit CT, Siemens Healthcare, Forchheim, Germany

syngo.via* is a new imaging software that supports the physician’s diagnostic work with indication-specific workflows, layouts, and tools. Unlike typical radiolog-ical workplace setups – often equipped with multiple, isolated workstations – syngo.via is a server-based imaging soft-ware that can be seamlessly integrated in PACS or RIS-based working scenarios, accessible from any** PC within a clinical network. To give an overview of the many oppor-tunities for saving time in CT, an easy to use tool has now been created: the syngo.via CT Speedometer. The CT Speed-ometer shows exactly how utilizing syngo.via can save time during the whole workflow, from patient registration over reading the cases up to distributing the report. Many time-consuming steps which previously had to be done manually can now be avoided.The following illustrates just a few of the time-saving features that are quickly locat-ed and explained with the CT Speedometer:

will also be created automatically (Fig. 1A).Summary: There is no need to prepare the data set before being able to read the case.

One Click Stenosis – Measurement Straight AwayIn cardiac evaluations, three reference points are automatically placed before, in and after a stenosis by syngo.CT Coronary Analysis.*** The entire vessel lumen can be controlled with a dedicated profile curve displayed next to the vessel. By accepting the measurement, the results – including the images – are documented in the Findings Navigator (Fig. 1B).Summary: There is no need to go through the entire case manually.

Multimodality Oncology – Holistic Oncology Imaging Because syngo.via provides multimodality imaging, it can provide additional and

Image Prefetching – Up-to-date imaging HistoryAs soon as the patient is registered or data arrives, syngo.via automatically initiates a query in all connected archives (e.g. PACS) for previous exams or reports. Any reasonable previous examinations of a patient from CT, MR, AX or other moda-lities are prefetched. Thus, a com-plete imaging history is available before the physician starts reading the case. Summary: Manual, time-consuming querying and loading data is history with syngo.via.

Preprocessing – Reading can be Started Faster Than Ever BeforeFor example, as soon as a vascular case arrives at the server, syngo.via automati-cally starts to preprocess the data set. In this case, the table removal, bone removal and the labeling of main vessels will be automatically done by syngo.CT Vascular Analysis.*** Curved MPR reformations and orthogonal views of the main vessels

syngo.via can be used as a standalone device or together with a variety of syngo.via based software options, which are medical devices in their own rights. Prerequisites includes: internet connection to clinical network, DICOM compliance, meeting of minimum hardware requirements, and adherence to local data security regulations.The syngo.CT Vascular Analysis and syngo.CT Coronary Analysis options are pending 510(k) review and are not yet commercially available in the U.S.

***

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potentially decisive diagnostic information in oncology cases. Any image data, in addition to CT, from PET, MRI or ultra-sound available for the patient, can easily be integrated into the oncology reading layout with drag and drop (Fig. 1C). Summary: There is no need to switch between different data-sets or interfaces.

Lesion Picking – One Click SynchronizationIn Neuro Cases, syngo.via offers a one-click aneurysm evaluation. By simply clicking on the finding, e.g., in the VRT view, the same finding will be centered in the axial, coronal and sagittal views, and the other way round (Fig. 1D).Summary: No manual update of corre-sponding windows is necessary.

Findings Navigator – Reproducible ResultsWhile reading the patient, findings and measurements can be created, for example, the grade of stenoses or

The speedometer shows exactly how much time can be saved with syngo.via. www.siemens.com/ct-speedometer

lengths of aneurysms. These are auto-matically saved in the Findings Navigator. Whenever a user opens a case, the last findings are still there. By clicking on a finding, the image will again be displayed as it was before the last save. Summary: No difficult reproduction of old measurements is necessary.

“With syngo.via, I can cut the time for my cardio-vascular diagnosis from 25 minutes to only 4 minutes.”

Stéphane Rusek, PhD, Centre Cardio-Thoracique de Monaco, Monaco

“In an acute care case, e.g. a whole body scan with multiple fi ndings – syngo.via can save up to 23 minutes to diagnosis.”

Marco Das, MD, University Hospital, Maastricht, The Netherlands

“When reading an oncology follow-up examination such as a PET/CT which demonstrates multiple foci of cancer, comparison with prior appearance is essential to report response of therapy, syngo.via can reduce this total interpretation time by 65 %.”

James Busch, MD, Specialty Networks, USA

“Due to the automatic pre-processing of syngo.via a substracted case of CT Neuro DSA can be seen imme-diately instead of waiting up to 5–12 min post-processing time with a traditional CT Neuro DSA software.”

Jacques Kirsch, MD, Department of Radiology, Hospital Notre-Dame, Tournai, Belgium

Reporting – Complete Summary Automatically

Finally, when the reading physician is ready to close a case, a summary including all image findings and measurements will be created and saved to the PACS system. Work can be finished with a few easy clicks. There is no need to fax or mail results.

1 Time saving opportunities with syngo.via:

In preprocessing alone, up to 7 min can be saved (1A). In cardiac evalua-tion, one-click stenosis measurement (1B) saves an additional 4 min. This also applies to multimodality onco-logy reading (1C), and with CT Neuro DSA aneurysm evaluation (1D), up to 1 min can be saved (results may vary; data on file).

More time saving features can be found in the CT Speedometer. www.siemens.com/ct-speedometer

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International CT Image Contest – Highest Image Quality at Lowest DoseBy Rami Kusama, Business Unit CT, Siemens Healthcare, Forchheim, Germany

Excellent image quality is an essential requirement in computed tomography (CT). At the same time, the patient’s radiation exposure should be kept as low as possible. Siemens wants to motivate its users to utilize all dose reduction features available on their CT scanners to the full extent and share their experi-

1 Winner in Cardiac Moderate Atherosclerosis (SOMATOM Definition Flash / 0.97 mSv dose), Yuko Utanohara, MD and co-authors: Nobuo Iguchi, MD, PhD; Kenji Horie; Tatsunori Niwa; Sakakibara Heart Institute, JapanHistory:A 68-year-old female, non-smoker, with a 3-year history of hyperlipid-emia, shortness of breath and chest tightness on exertion was referred for detailed examination to our de-partment after heart murmur was detected for the first time.Diagnosis:The coronary arteries showed moderate atherosclerosis on CT.

Jury statement: “This case study is not only aestheti-

cally pleasing, but in addition, it demonstrates that supreme diag-nostic accuracy can be achieved at very low doses, with unambiguous visualization of the coronary artery lumen up to the very distal seg-ments of the coronary artery tree.”

ences with other users. For this reason, Siemens initiated the International CT Image Contest from October 1, 2009 to February 1, 2010 asking physicians from around the world to send in their work to compete for the best image quality at the lowest possible radiation dose. Around 300 low dose cases from more

than 30 countries were submitted and were evaluated by a jury of internation-ally renowned professors.

The JuryProfessor Stephan Achenbach University of Erlangen, GermanyProfessor Dominik Fleischmann

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Stanford University Medical Center, USAProfessor Elliot K. Fishman Johns Hopkins University Hospital, USAProfessor Yutaka ImaiTokai University School of Medicine, JapanProfessor Zengyu Jin Peking Medical Union College, ChinaProfessor Borut Marincek University Hospital Zurich, SwitzerlandProfessor Maximilian Reiser Ludwig-Maximilians-University Munich, GermanyProfessor Uwe Joseph Schoepf Medical University of South Carolina, USA

ParticipationImages could be submitted online on a contest website by users of the SOMATOM Definition, SOMATOM Defini-tion AS, as well as SOMATOM Definition

<<bitte überall mit Dosis-Tacho>><<bitte überall mit Dosis-Tacho>>

2 Winner in Neuro Perfusion after Occluded Stent (SOMATOM Definition AS / 7.55 mSv dose), Robert McGregor, MD; Bound-ary Trails Health Centre; CanadaHistory:Carotid CTA and perfusion imaging was obtained in a 55-year-old female post SILK stent for right internal carot-id aneurysm. Diagnosis:CTA revealed occlusion of the stented right internal carotid artery. Perfusion imaging demonstrated decreased CBF, increased MTT, but maintained CBV, indicating a large perfusion defect without significant infarction.

Winner in public voting: Interrupted Aortic Arch (SOMATOM Definition/ 0.45 mSv dose), Pannee Visrutaratna, MD, Maharaj Nokorn Chiangmai Hospital, Thailand

History: A five-month old girl has suffered from tachypnea, poor feeding, and poor weight gain since she was one month old.

Diagnosis: Interrupted Aortic Arch. The arch interruption occurs distal to the origin of the left subclavian artery. The descending thoracic aorta is supplied by a large patent ductus arteriosus.

Flash, in the categories of: cardiac, neuro, abdomen and pelvis, vascular, thorax, as well as Dual Energy. Every internet viewer could select their “favorite image” in a public voting.

Winner AnnouncementThe winner announcement took place at the ECR 2010 in Vienna during the Bayer Schering Pharma and Siemens Healthcare joint Satellite Symposium. Winning images (Figs. 1–6) were ex-hibited at the Grand CT Image Gallery. For those who could not attend the ECR, the winners were announced at the same time on the contest website and via press release.

Jury statement: “The case nicely presents the potential

of comprehensive stroke assessment by CT Perfusion. CT Perfusion may suffer from image noise with unsharp margins of the infarcted territory. In this example, the margins of the infarct are clearly displayed allowing determination of the extent of the infarction precisely.”

2

www.siemens.com/Image-ContestThe free contest poster can be ordered at: www.siemens.com/ct-poster


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4 Winner in Vascular Child Aortic Transposition (SOMATOM Definition Flash / 0.25 mSv dose), Gregory Nicaise, MD and co-author: Philippe Ever-arts, MD, Centre Hospitalier de Jolimont, BelgiumHistory:A 2-year-old child with chronic dyspnea and pulmonary infection was presented for a CT examination.Diagnosis:Aortic transposition, left bronchial stenosis, atelectasy, pulmonary clarity and air trap-ping were detected.

3 Winner in Abdomen and Pelvis Cancer of Pancreas (SOMATOM Definition / 6.34 mSv dose), Prof. Dan Han, MD and Yu-Hui Chen, MD; Hospital of Kun-ming Medical College; P.R. ChinaHistory:A 59-year-old male had experienced up-per abdominal pain for four years. A mass in the head and neck of pancreas was identified in both Ultrasound and MRI. Diagnosis:The advanced cancer of pancreas resulted in a significant narrowing in the portal vein and the collateral circulation was established.

Jury statement: “This CTA shows the encasement of the

portal vein / SMV confl uence making the patient unresectable. The case with the highest image quality is the one that pro-vides the most information content for the radiologist and the referring physician. This case fulfi lls these criteria completely at a very low radiation dose.”

Jury statement: “This case demonstrates excellent image

quality achieved at ultra-low dose permit-ting a comprehensive and accurate diag-nosis in a complex congenital heart de-fect.”

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5 Winner in Thorax Flash ECG Thorax (SOMATOM Definition Flash / 0.82 mSv dose), Petter Quick; CMIV Linköping University; SwedenHistory:A 47-year-old woman was presented to the CT-department with unspecific chest pain.Diagnosis:The CT examination showed no pathology and could successfully rule out coronary disease, pulmonary embolism as well as lung tumor.

6 Winner in Dual Energy Carotid and Circle of Willis (SOMATOM Definition Flash / 1.12 mSv dose), João Carlos Costa, MD, Diagnóstico por Imagem, Lda, PortugalHistory:A healthy 75-year-old female was presented to the CT-department with a family history of carotid artery stenosis.Diagnosis:Small atherosclerotic plaques in the emergence of braquiocephalic trunk and left carotid artery were identified.

Jury statement: “This case represented everything that

chest CT can be – a high quality, volume data set that can provide information for vascular imaging as well as the lung parenchyma. High quality imaging re-quires the right scanner, the right proto-cols and the right execution of these protocols. This image tells that story very nicely.”

Jury statement: “This case illustrates the power of Dual

Energy CT for tissue differentiation. In a single image and at tremendously low doses, all tissue layers in the human body can be simultaneously and intuitively displayed and provide the anatomic con-text of the target structure, the carotid circulation.”

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Business

Stéphane Rusek, PhD, is convinced that syngo.via radically transforms the use of CT even for his colleagues, turning it into an all’round tool for all doctors: (from left to right) Filippo Civaia, MD, Philippe Rossi, MD, Stéphane Rusek, PhD, Laura Iacuzio, MD.

Only a few meters up from the harbor, yet still within sight of the multi-million-dollar fleet resting in the sun, is located Monaco’s Centre Cardio-Thoracique where Stéphane Rusek, PhD, head of the hospital’s IT department, is trying to extract as much diagnostic information as he can for as little cost and time as possible.Rusek’s goal is to boost the productivity of radiologists and cardiologists by using computed tomography (CT) images to diagnose cardiac cases. And syngo.via,* Siemens’ groundbreaking imaging software, he’s convinced, is the answer. syngo.via has the capacity to help medical professionals use CT images more easily and efficiently, thus freeing

such examinations delivered around 50 images; nowadays they generate thousands – far too many for anyone to handle promptly and effectively.Rusek is convinced that syngo.via radi-cally transforms the use of CT, turning it into an useful tool for all doctors. “We are on the brink of a boom in cardio-vascular CT that will see it become standard and routinely used in every hospital,” he says. And the time seems ripe. Health authorities around the world appear increasingly willing to fund cardiac CT. They have been fun-ded in the USA since early 2010, and, in Europe, German health authorities are now looking into authorizing payment for cardiac related examinations. The

up more time for actual diagnosis.Stéphane Rusek is personally responsible for implementing Siemens’ latest break-through in image processing at the Monaco clinic. “A new era in image pro-cessing and CT diagnosis has dawned,” he says. “What the iPhone did for mobile computing, syngo.via is doing for CT. It offers a user-friendly interface that gets the most out of the technology without users even being aware of the sophis-ticated software responsible, let alone having to learn to manipulate it.” syngo.via has been specifically designed to free medical professionals from the burden of having to process the vast amount of images made available by today’s CT examinations. Ten years ago,

More for Less in MonacoAt Monaco’s Centre Cardio-Thoracique, Siemens’ latest groundbreaking image-processing software, syngo.via, is boosting the productivity of the cardio-vascular team.

By Oliver Klaffke


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certain result will be to make such exams more widely available.“The enormous benefit of the cardio-vascular applications in syngo.via is that they save time,” says Rusek. “Cardiologists no longer need to carry out tasks that can be done faster and better by software.” Preparing scans for diagnosis can be extremely time-consuming, especially in cardiac cases. For example, manually deleting the bony rib cage from images and high-lighting the arteries takes a lot of effort. In Monaco, before syngo.via, cardio-logists often needed up to half an hour just to prepare the images for diagnosis. Fortunately, time consuming and numerous mouse clicks to diagnosis may soon be no more than a distant memory. Today, cases can be automatically pre-pared and presented using syngo.via. “My guess is that five out of the six clicks that you once had to make with the mouse are no longer necessary,” smiles Rusek. As soon as his medical colleagues click to open a case in their inbox, syngo.via lets them get straight down to diagnosis. It will already have prepared the cases automatically and identified a process to meet the specific diagnostic needs. Images are imme-diately displayed in disease-related layouts along with the appropriate tools

for deeper investigation. The medical professionals are then carefully guided through a series of steps that they predefined in the software for their institution. “The syngo.via Cardio-Vascular appli-cation package** now cuts the time for cardio-vascular diagnosis from

25 to only 4 minutes – a factor of six.”

Information Available – Quality and Effi ciency

“Here in Monaco, we have benefited greatly from these disease-related work-flows,” says Rusek. For each diagnosis, syngo.via presents a to-do list to help professionals get all the necessary infor-mation reliably and in shortest time. Simply following these procedures is a great way to maintain the high stan-dards that are increasingly the norm in medicine. In Monaco, the cardiology team has completely redefined its standards and processes, thanks to syngo.via. “Now everybody working here uses the same processes,” says Rusek. “This greatly reduces the risk of errors and omissions during diagnosis.And since all relevant related data are stored along with the case and are re-trievable at the click of a mouse, writing reports has become much easier. “It’s

the perfect way to organize patient documentation, so that the physician in charge can work efficiently on the case,” says Rusek.In the past, cardiologists at Centre Cardio-Thoracique often had to switch between workstations to retrieve older data stored on different computers. No longer. “In our radiology department, that’s a thing of the past,” says Rusek. Using syngo.via, cases can be easily accessed from any computer linked to the hospital’s network. Gone is the need to wait until a workstation becomes available. At the PCs on their office desks, medical professionals can imme-diately and conveniently view any case they want. Even specialists working at a distance can log in utilizing a broadband internet connection and get the infor-mation they need quickly and efficiently. Siemens Healthcare is dedicated to making these benefits available every-where, not just for Stéphane Rusek and his colleagues on the beautiful shores of the Mediterranean Sea.

1 syngo.via CT Cardio-Vascular applications** for full cardiac assessment in less than 4 min: the automated case preparation, that saves up to 12 typical steps together with advanced visualization tools, like the Image Sharpening Filter for calcified lesions or stents, saves up to 21 min for a full cardiac assessment (results may vary; data on file).

1

Oliver Klaffke is a science and business writer based in Switzerland. He has been on assignment for New Scientist and Nature in the past.

syngo.via can be used as a standalone device or together with a variety of syngo.via based software options, which are medical devices in their own rights.The syngo.CT Vascular Analysis and syngo.CT Coronary Analysis options are pending 510(k) review and are not yet commercially available in the U.S.

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Business

New Feature: Neuro Image Quality Surpasses all ExpectationsA better and quicker workfl ow that leads to more time for patient care and diagnosis – this is the bottom line for Peter Schramm, MD, of the University of Göttingen, Germany, after testing the new features of syngo CT 2010B. But specifi cally for him, as neuroradiologist, the new dimension in neuro image quality is also a main improvement and a very impressive one.

By Wiebke Kathmann, PhD

The new software version, syngo CT 2010B, offers several new features in-cluding Neuro BestContrast, 4D Noise Reduction, Iterative Reconstruction in Image Space (IRIS), CARE Contrast II and Adaptive Signal Boost. Together they truly improve the diagnostic precision and workflow as could be clearly demon-strated during the Market Entrance Phase (MEP) by Peter Schramm, MD, Deputy Head of the Neuroradiology Department at the University of Göttingen. He was among the first

physicians worldwide to test the new features in the clinical environment on a SOMATOM Definition AS+ scanner. As a neuroradiologist, he was especially im-pressed by Neuro BestContrast because it achieves a very substantial improve-ment in image contrast, thereby signifi-cantly improving the distinction be-tween gray and white matter in the brain – a very important feature in the diagnosis of acute stroke patients where tissue changes on the scale of 5 to 10 HU can decide between life and death.

Neuro BestContrast absolutely fulfilled Schramm’s expectations. „Simply by looking at the images in our digital Picture Archiving and Communication System (PACS), we could recognize the point in time at which the new software had been installed. A lot of our patients get a follow-up CT scan, so we could also compare scans from before and after the software was implemented. When Siemens told us that they were aiming at improving the differentiation of brain tissue, we were wondering how

A better and quick-er workflow that leads to more time for patient care anddiagnosis – this is the bottom line for Peter Schramm, MD, of the Univer-sity of Göttingen.


“At some point in the future, neuroradiolo-gists may no longer need to perform the complete stroke CT protocol.”Peter Schramm, MD, University of Göttingen, Germany


Business

Wiebke Kathmann, PhD, is a frequent contributor to medical magazines in the German-speaking world. She holds a Master in biology and a PhD in theoretical medicine and was employed as an edi-tor for many years before becoming a freelancer in 1999. She is based in Munich, Germany.

they would be able to achieve an im-provement in contrast without losing spatial resolution. But they did – by processing low and high frequencies separately.“

One-Stop-ShoppingFor clinicians performing perfusion im-aging, 4D Noise Reduction is the most interesting feature. Static and dynamic components are treated separately as a means to reduce noise, thus improving the image quality and clinical outcome. Schramm could confirm this in acute stroke patients, who are frequently quite agitated. The main advantage, however, that Schramm sees with 4D Noise Reduction is a reduction in radiation dose while still being able to get all the diagnostic information from one 4D volume perfu-sion scan. “At some point in the future, neuroradiologists may no longer need to perform the complete stroke CT protocol consisting of a non-contrast CT, a whole brain perfusion CT including 4D spiral scans and a CT Angiography of the brain vessels. Due to the precision with 4D Noise Reduction, there could be ‘one-stop-shopping’, the non-contrast CT could be skipped by using the first of the multi-spiral CT images before the con-trast medium arrives and the angio-in-formation could be taken from one arte-

rial sequence. For the patient that would mean one instead of three CT scans, consequently a shorter examination time and, in the end, less radiation.“

Less RadiationWith the Iterative Reconstruction in Image Space (IRIS), Siemens recently introduced a new approach to addition-ally reduce dose by up to 60 % and, at the same time, improve image quality for a wide range of clinical applications. Af-ter an initial raw-data reconstruction, a newly developed master image is gener-ated followed by several iterative correc-tions that remove image noise without degrading image sharpness. With this approach, IRIS achieves a similar image quality as with true iterative reconstruc-tions but avoids the long reconstruction times, as multiple translations from and to the raw data are not needed. For Schramm, the main promise IRIS holds with this new method is a reduction of radiation dose. So far, he and his team have worked with the regular dose. After testing IRIS, they will now commence with a controlled, stepwise dose reduc-tion during the next few weeks. In 10 % steps with about 500 neuroradiological cases each, they hope to prove that IRIS allows a reduction of radiation dose while keeping the image quality at the same level. “Most likely, IRIS will allow for a reduction by 20 % in neuroradiology. In spinal CT, I expect a reduction by 25 to 30 % without any loss of image quality,” says Schramm. “In very obese patients and abdominal CT applications, I can realize a dose reduction of up to 60 %.“

Saving TimeRegarding the use of CARE Contrast II – the new coupling interface for scanner and bolus injector – Schramm experi-enced two advantages: first, the im-proved workflow for the technician due to the synchronization of injector and scanner and therefore improved patient care; second, and more important, the time saved due to the automatic and digital transfer of the whole dataset on contrast media, flow rate etc. to the patient protocol. ”This archiving of the complete data set – be it for legal, re-

search, or clinical purposes – saves time,“ explains Schramm.”This makes it a very interesting feature for both research and in clinical routine.“

Benefi t for the Obese PatientAs for the Adaptive Signal Boost, Schramm is convinced that it will im-prove diagnostic precision and reliability, for example in CT imaging of the spine. “This application is on the rise due to improvements in CT technology and the growing number of bariatric patients who simply do not fit into the MRT and where it is crucial to provide the re-quired image quality for clinical evalua-tion.” Here the Adaptive Signal Boost improves the diagnostic accuracy in soft tissue imaging, especially of paraverte-bral and intra-spinal structures. “In rou-tine examinations, these features do not

“Most likely, IRIS willallow for a reduction of radiation dose by 20-30 % in neuro-radiology.” Peter Schramm, MD, University of Göttingen, Germany

necessitate changes in the workflow for the technician,” says Schramm, “They hardly notice the changes, whereas the clinical results are very impressive for the radiologist at the end of the line.”



Clinical Results Cardio-Vascular

Case 1Adenosine Myocardial Stress Imaging Using SOMATOM Defi nition FlashBy Gudrun Feuchtner,1, 4 Robert Goetti,1 André Plass,2 Monika Wieser,2 Christophe Wyss,3 Fernando Vega-Higuera,5 Hans Scheffel,1 Michael Fischer,1 Hatem Alkadhi,1 Sebastian Leschka1

1 Institute of Diagnostic Radiology, University Hospital Zurich, Switzerland2 Clinic of Cardiovascular Surgery, University Hospital Zurich, Switzerland3 Cardiology Division, University Hospital, Zurich, Switzerland 4 Department of Radiology II, Innsbruck Medical University, Austria 5 Business Unit CT, Siemens Healthcare, Forchheim, Germany.

HISTORY

A 51-year-old male with atypical chest pain and intermediate coronary risk pro-file (cigarette smoking and hypercholes-terolemia) underwent two coronary 128-slice Dual Source CT Angiographies: the first under adenosine myocardial stress-imaging, the second at rest.

DIAGNOSIS

High-pitch CT Angiography showed severely calcified left coronary artery (Fig. 1C) with significant stenosis, and bare-metal stent in the RCA.Adenosine CT stress imaging showed a reversible myocardial perfusion

COMMENTS

Adenosine stress-imaging of reversible myocardial ischemia is feasable with 128-slice Dual Source CT with compre-hensive evaluation of coronary arteries. Assessment of PBV reversible ischemia with CT is helpful to improve accuracy of coronary CT Angiography, especially in cases of severe coronary calcification or limited in-stent lumen visibility.

defect indicating ischemia anteroseptal at midventricular level (Figs. 1A–1B) corresponding to left artery descending (LAD) stenosis. No defect was found in-ferior of right coronary artery (RCA) vas-cular territory. Invasive angiography confirmed a significant 90 % stenosis at mid LAD and a patent RCA bare-metal stent. Total radiation dose was 2.2 mSv for adenosine stress and rest CT scans using high-pitch Flash Spiral mode at 3.4 pitch factor. The delay between both scans was 5 minutes. Scan time was 0.44 seconds for each study, tube set-tings were 100 kV and 320 mAs, gantry rotation time was 0.28 s.

EXAMINATION PROTOCOL

Scanner SOMATOM Definition Flash

Scan mode Flash Spiral Pitch 3.4

Scan area Heart Slice collimation 128 x 0.6 mm

Scan length 135 mm Slice width 0.75 mm

Scan direction Cranio-caudal Reconstruction increment 0.4 mm

Scan time 0.44 s Reconstruction kernel B 26f

Tube voltage 100 kV / 100 kV Volume 80 ml

Tube current 320 mAs/rot. Flow rate 5 ml/s

Dose modulation CARE Dose4D Start delay 10 s

CTDIvol 3.09 mGy Postprocessing syngo CT Cardiac –

Effective Dose 2.2 mSv (in total) Function prototype*

Rotation time 0.28 s

*The product is not commercially available in the US.


Cardio-Vascular Clinical Results

1 By injecting adenosine under stress, a perfusion defect anteroseptal was shown (arrow, Fig. 1A), which was reversible after 5 minutes Rest Scan (arrow, Fig. 1B). A significant mid LAD stenosis was detected by CT, and quantified as 90 % by invasive angiography. Distal after steno-sis a severely calcified artery was found (arrow, Fig. 1C).

2 Short axis at midventri-cular level showed antero-septal myocardial perfusion defect during adenosine stress (Fig. 2A, arrow), which was reversible at rest (Fig. 2B, arrow).

3 Color maps of the myo-cardium showed black/dark areas (Fig. 3A, arrow) indicating ischemic myocardium during stress. There was no defect at the inferior myocardial region supplied by RCA corresponding to patent RCA stent (Fig. 3B, arrow).

4 Automated quantifi-cation of hypo-attenuating perfusion defect antero-septal midventricular during stress (Fig. 4A, arrow) re-presented with the prototype of the syngo CT Cardiac Function software,* including 3D segmentation (Fig. 4B). No perfusion defect inferior of RCA vascular territory could be detected (Fig. 4C, arrow).

2A

1A

3A

2B

1B

3B

4A

4B

4C

First CTA under adenosine stress Second CTA at rest

1C

* The product is not commercially available in the US.




Case 2 SOMATOM Defi nition Flash:Visualization of the Adamkiewicz Artery by IV-CTA in Dual Power Mode By Yoshiyuki Mizutani, MD* and Tomoko Fujihara**

*Department of Radiology, Sakakibara Heart Institute, Tokyo, Japan

**Application Department CT Team, Customer Service Division, Siemens-Asahi Medical Technologies, Tokyo, Japan

HISTORY

A 75-year-old female was referred to the radiology department of Sakakibara Heart Institute to examine where her Adamkiewicz artery originated before treatment of her thoracic descending aortic aneurysm (TAA). The patient was scanned with Dual Source CT in dual power mode.At the referring hospital, the patient

had been diagnosed with TAA (descend-ing aorta of 5.6 cm diameter) by com-puted tomography and echography as well as right coronary artery (RCA) steno-sis by conventional angiography. She was referred to Sakakibara Heart Insti-tute for surgical vessel replacement and coronary artery bypass grafting with saphenous vein graft to RCA.

DIAGNOSIS

TAA was clearly seen on the Dual Source CT images. An artery originating from a lumbar artery was detected, bifurcating from the aorta at the upper level of the 4th lumbar vertebra, entering into the spinal canal from the intervertebral fora-men between the 4th and 5th lumbar vertebrae and running along the spinal cord on the ventral side up to the lower

2

2 TAA was clearly seen on the Dual Source CT images (thin MIP).1 TAA was clearly seen on the Dual Source CT images (VRT).

1






Scan area Thorax-abdomen

Scan length 280 mm

Scan direction Cranio-caudal

Scan time 8.41 s

Tube voltage 100 kV / 100 kV

Tube current 600 eff. mAs

Dose modulation CARE Dose4D

Rotation time 0.5 s

Slice collimation 128 x 0.6 mm

Reconstruction 0.3 mmincrement

Reconstruction B36kernel

Volume 100 ml

Flow rate 5.0 ml/s

Postprocessing syngo InSpace

level of the 12th thoracic vertebra where it changed direction forming a hairpin shaped structure. It connected into the anterior spinal artery. According to these characteristics this artery was identified as the Adamkiewicz artery.The true lumen of the aorta was highly enhanced, reaching a CT value of 746 HU at the level between the 4th and 5th lumbar vertebrae whereas the Adam-kiewicz artery reached a maximum CT value of only 140 HU.

COMMENTS

The course of the Adamkiewicz artery needs to be determined before surgery for TAA repair to ensure that it is not damaged during surgery and to reduce the risk of postoperative paraplegia. However, visualizing the Adamkiewicz artery with intravenous (IV) CTA is a challenging task as injection and scan protocols need to be tailored to the loca-tion and size of this artery. Since the

Adamkiewicz artery is a tiny vessel, a fair amount of contrast media needs to be injected at reasonably high rates to ensure that this tiny vessel is enhanced. In addition, since the Adamkiewicz artery runs partially inside the spinal canal, enough dose needs to be applied to achieve a high signal to noise ratio (SNR) in an area surrounded by bones.Dual Source CT in the dual power mode combines the power of two X-ray tubes and two generators and can therefore provide twice as much X-ray output as a single source CT at the same pitch. As a result, areas that need additional dose can be scanned at high scan speed and appropriate tube current for a high SNR. The high scan speed was essential for visualizing the Adamkiewicz artery, since it required several seconds after enhancement of the aorta until the small arteries were enhanced, then quickly scan over the required long scan range while the small arteries were still enhanced.

4

4 Adamkiewicz artery connected into the anterior spinal artery.

3A

3 Adamkiewicz artery entering into the spinal canal (Fig. 3A) from the intervertebral foramen between the 4th and 5th lumbar vertebrae and running along the spinal cord on the ventral side up to the lower level of the 12th thoracic vertebra where it changed direction forming a hairpin shaped structure (Fig. 3B).

3B



HISTORY

A 71-year-old male was referred for eval-uation of stable chest pain syndrome and enrolled in a prospective cohort study to evaluate the diagnostic accuracy and clinical feasibility of dynamic myocardial stress perfusion imaging by cardiac CT. Coronary CT Angiography (CTA) and CT-based assessment of myocardial per-fusion under adenosine stress was per-formed prior to cardiac catheterization.


DIAGNOSIS

Coronary CTA revealed heavy calcified plaque and a mild to moderate lesion of the right coronary artery (RCA, Figs. 1 and 2). Dynamic adenosine stress perfu-sion imaging revealed homogeneous perfusion of the myocardium without defined perfusion defect (Figs. 4 and 5).

COMMENTS

Non-invasive myocardial perfusion imag-ing by CT may represent an attractive option to determine the hemodynamic relevance of obstructive coronary lesions, or lesions with limited evaluability due to heavy calcification. However, further validation using appropriate gold stan-dards is warranted.After undergoing the CT Perfusion scan, the patient received conventional medical therapy.

1 Maximum intensity display of the right coronary artery, demon-strating heavy calcified plaque in the proximal segment and calcified and non-calcified plaque in the intermediate segment, causing a mild to moderate stenosis (arrow).

1

Case 3Dynamic Myocardial Stress PerfusionBy Florian Schwarz, MD, Fabian Bamberg, MD, MPH, Christoph R. Becker, MD, Alexander Becker, MD, Konstantin Nikolaou, MD

Department of Clinical Radiology, University of Munich, Campus Großhadern, Munich, Germany

2 Curved multiplanar reformation of the left anterior descending coronary artery with minor calcified and non-calcified plaque in the proximal segment of the vessel (arrow).

2


3 Principle: dynamic volumetric myocardial stress perfusion to quantify Myocardial Blood Flow (MBF). Comparison of different time attenuation curve (TCA) pattern with a slower and lower peak (86 ml / 100 ml / min) in an ischemic segment (Fig. 3A) and normal blood flow (MBF 159 ml / 100 ml / min) in an healthy segment (Fig. 3B).




Scanner SOMATOM Definition

Scan mode Dynamic Stress Perfusion Mode Dose modulation no

Scan area Left ventricular myocardium CTDIvol 94.15 mGy

Scan length 72 mm Rotation time 0.28 s

Scan direction Cranio-caudal Slice collimation 32 x 1.2 mm

Scan time 31 s Slice width 3 mm

Heart rate 72 bpm Reconstruction increment 2 mm

Tube voltage 100 kV Reconstruction kernel B23f

Tube current 350 mAs/rot. Post processing syngo VPCT

Body Myocardium

4 Systolic reconstruction display of long axis, color-coded myo-cardial stress perfusion image of the left ventricle indicating homo-geneous perfusion (green) and the absence of a circumscribed perfusion defect.

4

5 Short axis color-coded perfusion map of the left ventricle demonstrating homogeneous perfusion (green) under adenosine stress.

5

3A

80

60

40

20

00 5 10 15 20 25 30

time [s]

CT [HU]100

80604020

00 5 10 15 20 25 30

time [s]

CT [HU]

3B




Case 4Pre-operative Exclusion of Coronary Artery Stenosis With Less Than 1 mSv DoseBy Sebastian Leschka, MD* and Andreas Blaha**

Institute of Diagnostic Radiology, University Hospital Zurich, Zurich, Switzerland

Business Unit CT, Siemens Healthcare, Forchheim, Germany

HISTORY

A 71-year-old male patient with a history of cerebral infarction caused by a high-grade stenosis of the left internal carotid artery and lysis therapy was now re-ferred to the radiology department to rule out coronary artery disease.In addition to the coronary CT Angio-graphy (CTA) examination a non-en-hanced calcium-scoring scan (CaSc) was performed.The CTA was acquired with a fast pitch spiral technique (Flash Spiral Cardio) while a mean heart rate of 56 bpm was present.

COMMENTS

In combination with the CaSc (0.35 mSv) and the CTA (0.8 mSv), an effective dose* of 1.1 mSv was applied to the patient to detect coronary artery disease. The entire acquisition time of the CTA was 280 ms; calcium scoring was acquired in 120 ms.The Flash Spiral cardio method quickly and reliably combines low radiation dose values with the accurate display of the coronary arteries in all segments.

DIAGNOSIS

In total, ten calcified lesions could be detected in the CaSc. Diffuse distribution of calcified deposits was observed in the right coronary artery (RCA), the left artery descending (LAD) and the left cir-cumflex coronary artery (CX). The total Agatston score was 130.CTA unveiled a normal coronary artery anatomy, right dominant coronary supply type with regular sized lumen of the coronary arteries. RCA and LAD showed no hemodynamic relevant lesions. CX coronary artery unveiled a stenosis smaller than 50% in its proximal seg-ment. A deep myocardial bridging of the LAD could also be depicted.

Threshold = 130 HU (102.7 mg/cm3 CaHA)

Artery Numbers of Calcium Score (2) Volume [mm3] (3) Equiv. Mass Lesions (1) [mg CaHA] (4)

LM 0 0.0 0.00 0.0

LAD 2 27.5 29.3 4.89

CX 3 48.3 50.5 8.57

RCA 5 53.6 66.2 10.81

Total 10 129.5 146.0 24.27

(1) Lesion is volume based, (2) Equivalent Agatston score, (3) Isotropic interpolated volume, (4) Calibration Factor: 0.790

*Effective Dose was calculated using the published conversion factor for an adult chest of 0.014 mSv (mGy cm)-1 [1]. [1] McCollough CH et al. Strategies for Reducing Radiation Dose in CT, Radiol. Clin. N. Am. 47: (2009) 27-40.

*

**






Scan mode Flash Spiral CorCTA Rotation time 0.28 s

Scan area Thorax Pitch 3.4

Scan length 130 mm Spatial Resolution 0.33 mm


Scan time 0.28 s Slice width 0.75 mm

Heart rate 56 bpm Reconstruction increment 0.7

Tube voltage 100 kV / 100 kV Reconstruction kernel B26f

Tube current 320 mAs/rot. Volume 60 ml

Dose modulation CARE Dose4D Flow rate 6 ml/s

CTDIvol 3.10 mGy Start delay Test Bolus

DLP 57 mGy cm Postprocessing syngo Circulation

Effective Dose 0.8 mSv syngo InSpace

2 MIP of the LAD shows myocardial bridging (arrow).

2

3 MIP of the first diagonal branch (D1) of the LAD, discovers plunge into myocardium.

3

1 VRT of the Coronary arteries shows deep myocardial bridging of LAD (arrow).

5 A stenosis is present in the proximal segment of CX artery (arrow).

5 6

6 Cross-sectional view displays the stenotic area of CX artery.

4 MIP of the coronary artery tree with removed blood pool of the left ventricle reveals calcifications (arrow).

1

4



Case 5Utilizing Ultra Low Dose of 0.05 mSv for Premature Baby With Congenital Heart DiseaseBy Jean-Francois Paul, MD1 and Andreas Blaha2

1Centre Chirurgical Marie Lannelongue, Le Plessis-Robinson, France2Business Unit CT, Siemens Healthcare, Forchheim, Germany


*Effective Dose was calculated using the published conversion factor for a pediatric (newborn) chest of 0.039 mSv (mGy cm)-1 [1]. To take into account that Siemens calculates the CTDI in a 32 cm CTDI phantom an additional correction factor of 2 had to be applied.[1] McCollough CH et al. Strategies for Reducing Radiation Dose in CT, Radiol. Clin. N. Am. 47: (2009) 27-40.

HISTORY

A premature baby was referred to the radiology department with diagnosis of congenital heart disease. An atrial and

left ventricular septum defect could be detected with echocardiography butwith a doubt about the exact origin and

course of right pulmonary artery (RPA).Therefore a low dose CT examination was requested, utilizing low kilovoltage (kV) and low milliampere seconds (mAs) to achieve ultra low dose radiation values.

DIAGNOSIS

A mild stenosis present at the ostium of the right pulmonary artery could be observed. Although the RPA showed an irregularity it had a normal anatomical course. The ventricular septum defect as well as the still open atrial septum could be clearly revealed by using oblique pla-nar reformations. The right coronary ar-tery was well depicted despite a heart rate of 157 bpm.

COMMENTS

The data acquisition was performed with a SOMATOM Definition Flash using the ECG-triggered sequential mode (Flash Cardio Sequence) which resulted in an ultra low dose value. Calculated with the dose length product (DLP) of 0.7, an estimated dose of 0.05 mSv could be achieved.*Using the Definition Flash low dose ac-quisition technique it was possible to de-tect this congenital heart disease (CHD) in a very early stage of the patients life.

1 CT imaging with VRT technique shows ventricular septal defect (arrows) and persistent foramen ovale (PFO, arrowheads).

1


2 3




Scan mode Flash Cardio Sequence Effective Dose 0.05 mSv

Scan area Thorax Rotation time 0.28 s

Scan length 33 mm Feed/Rotation one rotation


Scan time 0.18 s Slice width 0.75 mm

Tube voltage 80 kV / 80 kV Reconstruction increment 0.4 mm

Tube current 22 mAs / rot. Reconstruction kernel B26f

CTDIvol 0.18 mGy Postprocessing CT Cardiac Engine

DLP 0.7 mGy cm

4 Cranio-caudal view in VRT-tech-nique.

5 Fused VRT and MIP highlighting RPA (arrow).

2 Ventricular septal defect in MIP technique (caudo-cranial view, arrow); PFO (arrowhead).

3 Caudo-cranial view MIP shows mild stenosis and irregularity of the RPA (arrow).

4


5




Case 6SOMATOM Defi nition Flash: Pediatric Patient Without Sedation and Breath-HoldingBy Kaori Takada, MD* and Tomoko Fujihara**

Department of Radiology, Sakakibara Heart Institute, Tokyo, Japan

Application Department CT Team, Customer Service Division, Siemens-Asahi Medical Technologies, Tokyo, Japan

HISTORYA 4-year-old boy with Tetralogy of Fallot (TOF, Fig.1), pulmonary atresia (PA) and major aorto-pulmonary collateral arteries (MAPCAs) was referred to the radiology department of Sakakibara Heart Institute for a follow-up examina-tion using a SOMATOM Definition Flash, Dual Source CT in Flash Spiral mode following treatment of his pulmonary artery stenosis.The patient was diagnosed shortly after birth with TOF, PA, MAPCA. When he was 10 months old, a stent was inserted in the largest MAPCA and a central shunt was placed when he was 16 months old. When he was 2 years old, he underwent right and left modified Blalock-Taussig

CT images revealed a tortuous artery originating from a right subclavian ar-tery that supplied the right and left infe-rior lung lobes. The left lung was per-fused mainly by the left central pulmo-nary artery. The right middle lung lobe was perfused by the large right inferior diaphragmatic artery (its distal end was connected to an artery originating from the central pulmonary artery). Incidentally, the right coronary artery (RCA) was found to originate from the aorta at the upper level of left coronary artery, the left coronary cusp (Fig. 4), which could neither be seen in the previ-ously performed catheter angiography nor in a 16-MSCT examination.Based on these findings a catheter PTA of the pulmonary artery stenosis at the distal part of the stent was planned.

COMMENTS

Dual Source CT Angiography has emerged as an essential diagnostic tool for the assessment of complex congeni-tal heart disease. Nevertheless, dose has remained a concern, in particular when referring pediatric patients for cardiac CT. With the Flash Spiral mode of the second generation Dual Source CT, pediatric patients can be scanned at ultra low dose, as in this case at 1.63 mGy (effective dose 0.644 mSv). Apart from dose concerns, additional chal-lenges have been associated with imag-ing pediatric congenital heart disease

shunt surgeries (therefore the subclavi-an artery is connected with the pulmo-nary artery) within 9 months. Then, at the age of 3, an artificial vessel was con-structed from the right ventricle (RV) to the pulmonary artery by palliative Rastelli procedure. The patient now underwent a percu-tanous transluminal angioplasty (PTA) of pulmonary artery. A low dose, Dual Source CT scan in the Flash Spiral mode was ordered to confirm his postopera-tive condition, in particular concerning the pulmonary circulation. The patient’s weight was 15.6 kg (34.39 lb).He was not sedated and no breath-hold was needed during the scan. His mean heart rate was 95 bpm.

DIAGNOSIS

The Dual Source CT images showed that the RV-pulmonary artery conduit was patent and that the anastomosis site had no stenosis. Neither the right nor the left pulmonary arteries (about 4 mm diameter) presented any signifi-cant stenosis (Fig. 2).A stent was confirmed in the biggest MAPCA, which bifurcated from the descending aorta at the level of the left atrium. It went to the right superior and inferior lung lobes, and connected one artery originating from right central pul-monary artery. Although the stent itself was patent, a stenotic part was seen dis-tal of the stent (Fig. 3). The Dual Source

1 Ventricular septal defect that is one characteristic of TOF.

1

*

**




2 Both, right and left pulmonary arteries (about 4 mm diameter) had now significant stenosis.

3 Stent was embedded in largest MAPCA that showed a stenosis (arrow) distal of stent (arrowhead).

4 RCA originated from left coronary cusp (arrows).

2B 3B

2A 3A

4A

4B



Scan mode Flash Spiral

Scan area Thorax / Chest

Scan length 211 mm


Scan time 0.52 s

Tube voltage 80 kV

Tube current 104 eff. mAs

CTDIvol 1.63 mGy

Effective Dose 0.644 mSv


Pitch 3.4


Slice width 0.6 mm

Reconstruction increment 0.3 mm

Spatial resolution 0.33 mm

Reconstruction Kernel B26f, B46f (stent)

Contrast

Flow Rate 2.5 ml/s

Start delay 17 s

Volume 30 ml

patients: the patients have high heart rates, the cardiac vessels are tiny, seda-tion often presents a risk and most pa-tients cannot hold their breath. This Dual Source CT Flash scan of 211 mm

length was taken in only 0.51 seconds without sedation or breath-hold. Vessels were clearly visualized without artifacts. Even coronary anomaly could be seen despite the patient’s high heart rate of

95 bpm. Pulmonary artery in-stent ste-nosis could also be evaluated. The Dual Source CT Flash images were extremely helpful for further treatment planning.



Case 7SOMATOM Defi nition Flash:Dual Energy Coronary CT Angiography for Evaluation of Chest Pain After RCA RevascularizationBy Ralf W. Bauer, MD, J. Matthias Kerl, MD, Thomas J. Vogl, MD

Department of Diagnostic and Interventional Radiology, Clinic of the Goethe University, Frankfurt, Germany

HISTORY

A 54-year-old female patient underwent coronary stent percutaneous translumi-nal coronary angioplasty (PTCA) of the right coronary artery (RCA) four months ago for acute ST-elevation myocardial infarction of the inferioseptal wall. Now, the patient suffered from reduced physical power and labile blood

pressure and had an event of syncope three weeks ago. Invasive coronary angi-ography was performed to assess stent patency. In-stent occlusion of the mid and distal RCA with moderate collateral-ization from the left anterior descending (LAD) and left circumflex artery (LCX) and a patent right ventricular (RV)

branch were found (Fig. 1). Recanaliza-tion was performed with placement of 2 drug-eluting stents in the distal and mid RCA. During intervention, a small con-trast material extravasation was seen near the ostium in the proximal RCA. A small intima dissection was suspected and another stent was placed to close


1 Prior to recanalization: Cardiac catheteri-zation showed a prominent RV branch and in-stent occlusion of the mid and distal RCA (arrow).

1

2 Curved multiplanar reformates showed instent thrombosis with occlusion beginning in the proximal RCA. In the RV branch, which was clearly visible on pre-interventional cath images, no contrast material filling could be delineated (arrows).

3 Dual Energy iodine mapping showed a large area with decreased perfusion in the arterial phase in the inferoseptal wall extending from the base to the apex of the heart (arrow).

32





Scan mode Dual Energy

Scan area Heart

Scan length 170 mm


Scan time 4.8 s

Tube voltage A/B 100 kV/140 kV+Sn filter

Tube current A/B 165 mAs/140 mAs

CTDIvol 13.29 mGy


Pitch 0.17


Slice width 0.75 mm


Reconstructionkernel D26f

Volume 70 ml contrast media

Flow rate 5 ml/s

Start delay Test bolus

Post processing syngo Dual Energy


the leakage. Three hours after interven-tion, the patient developed chest tight-ness and retrosternal pain. ECG showed signs of the known old infarction inferiorseptally (Q waves in II, III and aVF) but no signs of acute ischemia. She was sent to CT to rule out aortic dissection.

DIAGNOSIS

Cardiac CT was performed in Dual Energy mode with retrospective ECG-gating. There was no sign of contrast material extravasation or aortic dissection. Dual Energy CT Angiography revealed in-stent thrombosis with occlusion of the RCA 13 mm after its origin (Fig. 2). While on cardiac cath the RV branch was still open, DECT showed an occlusion of the vessel due to the thrombus in the proxi-mal RCA, explaining the patient’s symp-toms. Dual Energy myocardial iodine mapping showed a large hypoperfused

area inferoseptal extending from the base down to the apex (Fig. 3). Low dose step-and-shoot late enhancement images 7 minutes after contrast injec-tion showed corresponding delayed contrast material washout (Fig. 4). On regular anatomical multiplanar refor-mates, a moderate thinning of the left ventricular myocardium was present in that area (Fig. 5).

COMMENTS

In this case, Dual Energy coronary CT Angiography was used to image a complication of interventional recanali-zation, i.e. acute in-stent thrombosis, while the initial clinical diagnosis of acute aortic dissection could reliably be ruled out. A further complication was the occlu-sion of the RV branch (which was patent prior to intervention) due to the large thrombus formation beginning very

proximally in the RCA. The new hybrid reconstruction algorithm for coronary CTA images preserves the high temporal resolution of 75 ms of the Dual Source system and allows for motion-free imag-ing of the vascular structures. According to the clinical history of the patient, assessment of the myocardium with Dual Energy first-pass perfusion and late enhancement imaging showed signs of chronic infarction in the inferoseptal wall of the left ventricle. Increased tube power as well as improved separation of the spectra by using a tin filter (140 kV + Sn filter) allowed for artifact-free im-aging of myocardial perfusion. Complete diagnostic work-up of the coronary arteries and the myocardium was achieved with a total dose length product of only 294 mGy cm (227 mGy cm CTA + 67 mGy cm late enhancement).

4 Late enhancement was present in the in-feroseptal wall corresponding to the perfusion defect in arterial phase.

4

5 Regular anatomical multiplanar reformates showed moderate thinning of the interoseptal wall consistent with chronic ischemia (arrow).

5


Clinical Results Oncology

Case 83D Guided RF Ablation and CT Perfusion – a New Combination for Monitoring of Treatment Response By Hatem Alkadhi, MD*,** and Jan Freund***

Institute of Diagnostic Radiology, University Hospital Zurich, Zurich, Switzerland;

Massachusetts General Hospital, Harvard Medical School, Boston, MA, USA


Today, there is a significant trend for more routine biopsies, as well as an in-creasing volume of more complex inter-ventional procedures such as radio fre-quency (RF) ablations and minimally invasive surgical procedures. In addition, the need for large perfusion ranges is in-creasing with the demand for complete and comprehensive assessments of the whole disease in the entire organ. The current challenge in CT interventions is to overcome the limitations of conven-tional 2D CT guidance where, especially in difficult cases, the safe navigation of the needle is a challenge.A more accurate overview of the needle position and surrounding organs has often been lacking during difficult pro-

cedures, especially when using oblique needle positions in both fluoroscopic and non-fluoroscopic procedures. Strongly motivated by the increased vol-ume of these interventions, radiologists have been looking for a solution that adds precision while reducing procedure time, freeing up the CT suite for more patients and procedures and, in addition, bringing new revenue opportunities. At University Hospital Zurich, radiologists are working on an impressive and prom-ising solution utilizing Siemens’ real-time 3D image guidance for minimally invasive procedures and CT Perfusion in combination with the innovative Adaptive 4D Spiral technology. The fol-lowing case demonstrates a 3D guided

RF ablation of a renal cell carcinoma with a combined monitoring of treat-ment response by Adaptive 4D Spiral volume perfusion CT.

PATIENT HISTORY

An 80-year-old female patient presented to the emergency department with mac-rohematuria. A CT of the abdomen revealed a mass in the left kidney that was suspicious of a renal cell carcinoma (Fig. 1). Because severe co-morbidities prevented open surgery, the patient was scheduled to undergo radio frequency ablation (RFA). Considering the large size of the tumor, embolization of the mass was performed prior to RFA (Fig. 3).


2 The image shows the RFA procedure of the left kidney tumor.

2

3 Selective catheter angiography of the left renal artery demonstrating the hyper-vascu-larized tumor of the lower pole (left). Angi-ography after embolization shows subtotal devascularization of the tumor (right).

3

1 Contrast-enhanced abdominal CT shows an exophytic mass in the left kidney (arrow).

1

*

**

***


Oncology Clinical Results


DIAGNOSIS

Due to the large size of the tumor, con-ventional CT Perfusion studies are nor-mally unable to capture the entire tumor and therefore deliver only partial perfu-sion information. To circumvent this limitation, the patient was sent for a volume perfusion scan to the SOMATOM Definition AS offering the Adaptive 4D Spiral scan modes. This allows CT Perfu-sion coverage of up to 7 cm. The Adap-tive 4D Spiral scan was performed one day after embolization. It showed the tumor to be largely devascularized. However, a small proportion in the me-dial lower part of the tumor still showed blood flow (Fig. 4).Two days later, a CT-guided RFA was per-formed using the Adaptive 3D Interven-tion Suite with its needle path planning and on-line tracking mode. Particularly the perfused tumor part as demonstrat-ed by perfusion CT was targeted (Fig. 2). In order to safely reach the dedicated areas, a 3D visualization of axial, coronal and sagittal slices during the intervention was used. In combination with a 2-click

path planning, a fast and precise needle navigation was ensured. Radiation expo-sure could be kept very low by applying an interventional sequence scan mode for needle navigation. A CT Perfusion study performed the day after RFA shows complete devascu-larization of the tumor (Fig. 5) indicating a successful treatment of the patient. With the ability to perform perfusion studies over the entire region of interest, it is now possible to assess the extent of the disease and visualize the function of potential metastases. The combination of CT Perfusion studies and CT guided RFAs allows the reading physician to more precisely assess the treatment success after RFA in a timely manner. This makes it possible to monitor devascular-ization of the kidney tumors only one day after RFA.

COMMENTS

The increased precision of the 3D visual-ization especially helps to more precisely position RF needles to ensure the correct placement in the perfused tumor area.

It gives a more accurate overview of the needle position and surrounding organs during difficult procedures, such as oblique needle positions of RFAs. This ensures a higher success rate of RF treat-ments. In addition, the automated needle guidance and tracking tool significantly helps to speed up the insertion and needle placement with a reduced pa-tient exposure. The 3D minimal invasive suite in parti-cular now offers the freedom to direct the entire procedure with just the touch of a button – without ever leaving the patient’s side. No ongoing, extensive communication with the technician for additional distance measurements, windowing and image adjustments is necessary. Since the user is now able to easily switch between fluoroscopic, sequential and spiral examinations without time-consuming scan protocol manipulation, the physician saves additional time reducing the overall interventional procedure time. This frees up the valuable CT suite more quickly for waiting patients and proce-dures.

4 Blood volume map shows a largely devascularized tumor after embolization treatment, however, also a strongly perfused area in the medial, lower part of the tumor (red, yellow).

4

5 Blood volume map shows complete devascularization of the kidney tumor (purple, blue) after RF treatment.

5


Clinical Results Oncology


Case 9SOMATOM Defi nition Flash: Routine Re-staging of Oesophageal Carcinoma Utilizing IRIS TechnologyBy Michael Lell, MD*and Andreas Blaha**

*Department of Radiology and the Imaging Science Institute (ISI), University of Erlangen-Nuremberg, Erlangen, Germany

**Business Unit CT, Siemens Healthcare, Forchheim, Germany



Scan mode Thorax DLP 260 mGy cm

Scan area Thorax-Abdomen Effective Dose 3.9 mSv

Scan length 656 mm Rotation time 0.33 s


Scan time 21 ms Slice width 0.75 mm

Tube voltage 120 kV Reconstruction increment 0.4 mm

Tube current Ref.mAs 100 eff. mAs Reconstruction kernel I41

Dose modulation CARE Dose4D Postprocessing syngo CT 3D

HISTORY

The 55-year-old male patient presented with a history of oesophageal cancer.He previously underwent combined radio-chemotherapy. CT was requested for re-staging to discuss further therapy options for the patient.

DIAGNOSIS

A contrast enhanced CT revealed bilateral well-perfused lung, also the port catheter was well positioned in the vena cava superior. Following treatment, there was still prominent thickening of the wall of the distal oesophagus und enlarged

lymph nodes in the mediastinum. In addition, a small pericardial effusion, most probably a side effect of radio-therapy, was visualized. There was no evidence of liver or lung metastases and there were no enlarged lymph nodes at the level of the celiac trunk. An isolated solitary cyst (Bosniak I) was located in the upper left kidney.

COMMENTS

Several measures to reduce dose were employed with this patient. Online tube current modulation (CARE Dose4D) and

iterative reconstruction in image space technology (IRIS) were utilized, which lead to a significant reduction in dose and noise as compared to conventional CT, improving image quality. This exa-mination reliably demonstrated the possibility of acquiring excellent image quality at reduced dose levels (3.9 mSv / DLP: 260 mGy cm).


Oncology Clinical Results


1

2 Coronal cut demonstrates the solitary cyst (left kidney, arrow), and distal oesophageal wall thickening (arrowhead, IRIS reconstruction).

2

3 Axial slice highlights wall thickening of the oesophagus (arrowhead), and pericardial effusion (arrows).

3

4 Low and homogenous noise in the entire dataset using IRIS (coronal slice) reveals oesophageal thickening (arrows).

4

1 VRT and fused MPR show the extension of oesophageal wall thickening.


Clinical Results Neurology

Case 10SOMATOM Defi nition AS+: CT Perfusion With Extended Coverage for Acute Ischemic StrokeBy Ke Lin, MD

Department of Radiology, New York University Langone Medical Center, New York, USA


HISTORY

A 53-year-old male with history of hyper-tension presented with sudden onset of expressive aphasia and weakness. The patient had experienced two similar but transient episodes in the previous

12 months. He arrived to the emergency department of NYU Langone Medical Center within 1 hour of symptom onset and was immediately evaluated for acute ischemic stroke by non-contrast

head CT (NCCT), dynamic CT Perfusion (CTP) of the brain, and CT Angiography (CTA) of the cervical and intracranial arterial vasculature.

11 Dynamic CT Perfusion (CTP) cerebral blood flow (CBF) map shows markedly decreased CBF to the left frontal operculum. CTP cerebral blood volume (CBV) map shows matched decreased CBV in this region indicating irrevers-ible infarct core. A penumbra-core map generated by using thresholds of CBV ≤ 1.2 ml / 100 ml for core (red) and CBF ≤ 35 ml / 100 ml / min and CBV >1.2 ml / 100 ml for penum-bra (yellow) shows little salvageable tissue at this level.



Neurology Clinical Results

2 The penumbra-core maps from selected slices above and below the level shown in Fig. 1: the extents of both the salvageable ischemic penumbra (yellow) and the irreversible infarct core (red) are fully de-picted.


Scanner SOMATOM Definition AS+

Scan mode Adaptive 4D Spiral Rotation time 0.3 s

Scan area Head Slice collimation 64 x 0.6 mm

Scan length 96 mm Slice width 10 mm

Scan direction Caudo-cranial and cranio-caudal Reconstruction increment 5 mm

Scan time 45 s Reconstruction kernel H20f

Tube voltage 80 kV Contrast Volume 50 ml iodine

Tube current 200 eff. mAs Flow rate 5 ml/s

Dose modulation CARE Dose4D off Start delay 4 s

CTDIvol 218.8 mGy Postprocessing syngo VPCT Neuro

DIAGNOSIS While NCCT showed only subtle blurring of the normal gray/white matter inter-face at the left frontal operculum, CTP with extended coverage revealed the full extent of the acute ischemia in the ante-rior left middle cerebral artery (MCA) territory. There was severe compromise of cerebral blood flow (CBF) to the mid and inferior left frontal lobe. At the level of the operculum (Broca’s area), there was a matched defect in low CBF and low cerebral blood volume (CBV) indica-tive of irreversible infarct core (Fig. 1). However, there was appreciable CBF/CBV mismatch on the other acquired slices,

indicative of salvageable tissue at risk (Fig. 2). CTA showed embolic occlusion of the frontal opercular division of the left MCA secondary to plaque rupture at the left carotid bulb. The patient was then rapidly treated with intravenous thrombolytic therapy with mild improve-ment of symptoms.

COMMENTS

The SOMATOM Definition AS+ scanner with 128-slice configuration and Adaptive 4D Spiral technology allows larger CTP coverage with a single bolus of contrast.

In this case, the setting with 96 mm of z-direction coverage (and 1.5 seconds temporal resolution) covered nearly the entire supratentorial brain. syngo VPCT Neuro extracts first-pass data from the 45 seconds dynamic acquisition en-abling a rapid exam. The extents of both the salvageable ischemic penumbra and the irreversible infarct core were fully depicted. Rescue of ischemic penumbra is the main rationale for aggressive stroke intervention, and its identification through perfusion imaging may form the basis of patient selection for therapy in the near future.

2



Case 11Vasospasm After Subarachnoid Hemorrhage: Volume Perfusion CT NeuroBy Bruno A. Policeni, MD

Radiology Faculty, Neuroradiology, University of Iowa Hospitals and Clinics, Iowa City, Iowa, USA

HISTORY

A 36-year-old female with a history of migraine developed a sudden onset of the worst headache of her life, lost con-trol of the entire right side of her body and fell to the floor. However she had no trauma to her head and did not lose consciousness. She was admitted to the emergency department where a head CT (Fig. 2) showed right sylvian fissure and inter-hemispheric fissure hyperdensity consistent with subarachnoid hemor-


rhage. The temporal horns were mildly dilated due to early obstructing hydro-cephalus and a small amount of intra-ventricular blood was present in the left occipital horn. A CT Angiography was performed and showed a 7 mm x 4 mm bi-lobed berry aneurysm with a narrow neck arising from the M1 segment of the right mid cerebral artery (MCA, Fig.1). The patient was transferred to the angiography suite for conventional

1 3D CT Angiography shows a right mid cerebral artery (MCA) bi-lobed aneurysm (arrow). No other aneurysms were found.

angiography, confirming the right MCA aneurysm (Fig. 3). She underwent im-mediate aneurysm coil embolization. On day four after the intervention, her neu-rologic exam attested deterioration and she showed a left facial palsy, indicating suspected vasospasm. The patient was referred to the radiology department for comprehensive stroke imaging, includ-ing CT Angiography and Volume Perfu-sion CT (VPCT) of the brain to rule out vasospasm.

DIAGNOSIS

Using the Adaptive 4D Spiral technology a 9.6 cm volume perfusion scan cover-ing the entire brain was performed and the resulting perfusion parameter maps were qualitatively and quantitatively evaluated in 3D. They demonstrated an impaired brain perfusion in the right MCA and ACA vascular territory distribu-tion with prolonged Mean Transit Time (MTT), reduced Cerebral Blood Flow (CBF) in the same area and slightly increased Cerebral Blood Volume (CBV, Fig. 4). CT Angiography images were ob-tained from the dynamic VPCT data and showed areas of narrowing in the right MCA and anterior cerebral artery (ACA, Fig. 6). The following angiography con-firmed the vasospasm findings consis-

1

L R



3 Conventional angiography demonstrates the right MCA aneurysm in the right internal carotid artery injection (ar-row).

4

2 Head CT without contrast demonstrates right sylvian fissure and interhemispheric fissure hyperdensity consis-tent with subarachnoid hem-orrhage (arrows). The tempo-ral horns are mildly dilated due to early obstructing hydrocephalus (arrowhead).

2 3


4 VPCT axial multi-parameter view showing a Maximum Intensity Projection (MIP), Cerebral Blood Flow (CBF), Cerebral Blood Volume (CBV), Time To Peak, Time To Drain (TTD) and Mean Transit Time (MTT), MTT and TTD (time to drain, a Siemens origin parameter) being the most useful parameters in this case.




tent with segmental narrowing in the right MCA/ACA and delayed capillary transit time (Fig. 7A). The patient was immediately treated with 8 mg intra-arterial nicardipine for a period of 10 minutes and balloon angioplasty was performed in the right MCA. Immediate follow-up confirmed a successful treat-ment (Fig. 7B) and there was also an im-provement in the neurologic exam, specifically in the left facial palsy. The patient was discharged on day 17, neu-rologically stable with resolution of the

facial droop, well-controlled pain and ambulating without assistance. She was scheduled for a follow-up exam in the clinic 6 weeks later.

COMMENTS

syngo VPCT Neuro offers dynamic perfu-sion analysis of the entire brain. That, as in this case, enables the detection of vasospasms – even those located in upper brain regions or in the posterior fossa, not covered by traditional Perfu-

sion CT through the base of skull. Thus syngo VPCT Neuro in combination with the Adaptive 4D Spiral technology is en-hancing the diagnostic application. The ability to obtain a CT Angiography with the same data acquisition is crucial for the correlation to the vascular territory showing prolonged MTT. Temporal pa-rameter maps like MTT in 2D and 3D delivered by syngo VPCT Neuro may act as a sensible tool to detect perfusion asymmetries in the two hemispheres as an indicator for vasospasm.

5 3D view of the Time To Drain (TTD) parameter map of the entire brain. Time to drain is a Siemens unique deconvolution based parameter de-scribing the time of the earliest washout of contrast medium in seconds. It is a very sensitve parameter to detect perfusion asymetries like MTT.

5




7 Conventional angiography confirmed severe vasospasm (arrows): segmental narrowing in the right MCA/ACA and a delayed capillary transit time (Fig. 7A). Follow up demonstrates resolution of the vasospasm after nicardipine injection and balloon angioplasty (Fig. 7B, arrows).

6 Coronal CTA MIP reconstruction from the dynamic series demonstrates areas of severe vasospasm (arrows) in the right ICA and MCA compared to the normal left MCA (arrowhead).


Scanner SOMATOM Definition AS+

Scan mode Adaptive 4D Spiral (spiral shuttle mode) Rotation time 0.3 s

Scan area Head Slice collimation 128 x 0.6 mm

Scan length 96 mm Slice width 5 mm for perfusion, 1 mm for CTA

Scan direction Cranio-caudal and caudo-cranial Reconstruction kernel H20f

Scan time 45 s; 30 scans total Volume 40 cc Isovue-370 and 50 cc normal saline

Tube voltage 80 kV Flow rate 8 ml/s

Tube current 200 mAs Start delay No delay

CTDIvol 218 mGy Post processing syngo Volume Perfusion CT Neuro

7A 7B

6


Clinical Results Acute Care

Case 12Dual Energy Scanning: Diagnosis of Ruptured Cocaine Capsule By Ralf W. Bauer, MD, J. Matthias Kerl, MD, Thomas J. Vogl, MD, Philipp Weisser, MD

Department of Diagnostic and Interventional Radiology, Clinic of the Goethe University, Frankfurt, Germany

HISTORYA 32-year-old male passenger on a flight from South America landed at Rhein-Main International Airport in Frankfurt. He showed a conspicuous and slightly delirious behavior. The customs and border police were alert and questioned him whether he was carrying or had consumed drugs. At first, he denied, but as his medical condition dramatically worsened, he admitted that he had swallowed 24 self-packed capsules with columbian cocaine. The patient devel-oped heavy attacks of abdominal cramps and became more and more apathetic. He was transferred to the hospital to lo-calize the capsules, to confirm the num-ber, and to check, if one of the capsules had opened and cocaine had come into the bowel lumen – or if the capsules had caused an ileus.

DIAGNOSISA contrast-enhanced, Dual Energy CT (DECT) scan of the abdomen was per-formed. 24 capsules with an average size of 2.5 x 3.5 cm and hyperdense content were found, confirming the patient’s story. Average CT values of the hyperdense content were 203 HU at 80 kV and 140 HU at 140 kV. The cap-sules were spread all through the small bowel and colon. However, there was one capsule in the rectum, that was sig-nificantly larger than the others and its content showed lower attenuation val-ues of 139 HU at 80 kV and 77 HU at 140 kV. DECT further revealed a thin hy-perdense layer-like structure that peeled off from that capsule, therefore the sus-picion arose that the capsule actually had ruptured. Rectoscopy was per-formed immediately and the torn cap-


sule was secured. The patient recovered on the intensive care unit without fur-ther major medical treatment and could be relieved from the rest of his freight with the use of laxatives.

COMMENTS

With the use of DECT, a reliable diagnosis of the ruptured cocaine capsule could be performed and immediate medical help provided. To our knowledge this is the first report on the Dual Energy behaviour of columbian cocaine. This might be of future relevance for in vivo differentiation of cocaine or heroin of different origin in uncommunicative body packers. However, further research in this field is needed to confirm our results.



Scan mode Dual Energy Rotation time 0.5 s

Scan area Abdomen Pitch 0.55

Scan length 464 mm Slice collimation 14 x 1.2 mm

Scan direction Cranio-caudal Slice width 1.5 mm

Scan time 24 s Reconstruction increment 1.0 mm

Tube voltage A/B 140 kV / 80 kV Reconstruction kernel D30f

Tube current A/B 49 eff. mAs / 212 eff. mAs Contrast Volume 90 ml


CTDIvol 9.14 mGy Postprocessing syngo Dual Energy


4 Ruptured cocaine capsule. Arrows point at the loose outer layer.


1 Cocaine capsules distributed throughout the whole intestine.

3 Color-coding of cocaine capsules facilitates detection and counting.

5 ROI measurements demonstrate typical Dual Energy values of columbian cocaine.

3

5

1

Neuroradiology Clinical Results

2 Virtual colonoscopy view.

6 The coronal reformate shows large amounts of fluid in the colon lumen. However, no ileus was present.

4

6

2



Case 13Progressive Kidney Hematoma Post-interventional Biopsy By Sebastian Leschka, MD * and Andreas Blaha **

*Institute of Diagnostic Radiology, University Hospital Zurich, Zurich, Switzerland


HISTORY

To determine further therapy, the 21-year-old patient, status after hepatitis B, was referred to the radiology depart-ment. Here a biopsy of the renal paren-chyma was performed upon which a haemorrhage occurred, accompanied by the formation of a hematoma. A 3-phase kidney CT was performed. Due to the nephritic syndrome only 60 ml of con-trast media with a flow rate of 4 ml/s followed by a 60 ml NaCl bolus (4 ml/s) was injected for the kidney CTA.

1 Fused VRT/MPR highlight kidney hematoma.

DIAGNOSISIn the native phase, an accumulation of liquid at the lower left renal pole was seen. The arterial phase showed an extravasation of contrast media out of the left kidney. An inhomogeneous hematoma measuring 15 x 7.5 x 5 cm was detected around the left kidney. Both kidneys were perfused symmetri-cally, unique renal arteries were seen bilaterally. In the venous phase a normal renal calyx developed on both sides.

COMMENTS

Despite the low quantity of applied con-trast media, a contrast media enhance-ment in the left kidney could be identi-fied due to a quick acquisition time of 0.7 seconds. The SOMATOM Definition Flash allowed a precise and rapid diagnosis with a reduced given patient radiation dose of 3.3 mSv.

1



Acute Care Clinical Results



Scan mode 3-phase kidney Rotation time 0.28 s

Scan area Abdomen Pitch 2.1

Scan length 218 mm Slice collimation 128 x 0.6 mm

Scan direction Cranio-caudal Slice width 2 mm

Scan time 0.7 s Reconstruction increment 1 mm

Tube voltage 120 kV / 120 kV Reconstruction kernel B30f

Tube current 100 eff. mAs Contrast Volume 60 ml Iodine


CTDIvol 7.71 mGy Postprocessing syngo CT 3D

syngo InSpace

2 Axial non-enhancement multiplanar reformation (MPR, Fig. 2A); axial early enhancement MPR shows haemorrhages in the kidney hematoma (arrow, Fig. 2B). Axial late state MPR shows persistent bleeding (arrow, Fig. 2C).

3 Sagittal non-enhancement MPR (Fig. 3A); sagittal early enhancement MPR shows hemorrhages in the kidney hematoma (arrow, Fig. 3B); sagittal late state MPR shows persistent bleeding (arrow, Fig. 3C).

3C

2C

3B

2B2A

3A



Case 14SOMATOM Defi nition Dual SourceHigh Pitch vs. Routine Pitch Scanning in a Pediatric Lung Low Dose ExaminationBy Harald Seifarth, MD,* Walter Heindel, MD,* Andreas Blaha **

*Department of Clinical Radiology, University Hospital, Münster, Germany



HISTORYA 5-year-old male patient with a history of neutropenia after stem-cell trans-plantation was referred to the radiology department. The patient presented with persistent fever despite ongoing treat-ment with antibiotics. A CT examination was scheduled to exclude the presence of pulmonary mycosis. The CT examination was performed with a high pitch proto-col (pitch = 3.0), resulting in a scan time of only 0.9 seconds.

DIAGNOSIS

The present CT examination showed no signs of any fungal pulmonary infection or other inflammatory changes. Minor bilateral, subpleural dystelectases could be observed. In the previous examination (pitch 1.4, scan time 4.5 seconds, scan length 189 mm, 50 ref mAs), artifacts due to respiratory motion during the acquisi-tion hampered the evaluability of the exam. The study showed small pulmo-nary infiltrates.

2 Regular scan – axial slice of high resolution regular scan.

1 High pitch scan – axial slice of high pitch acquisition, no motion artifacts (arrow) due to breathing.

1 2

3 High pitch scan – entire lung in low dose technique (10 eff. mAs), no motion artifacts are visible.

3

4 Regulars scan – artifacts due to respiratory motion (arrows).

4



Acute Care Clinical Results



Scan mode Thorax HiPitch

Scan area Thorax

Scan length 159 mm


Scan time < 1s

Tube voltage A/B 120 kV / 120 kV

Tube current A/B 10 eff. mAs

Dose modulation CARE Dose4D

CTDIvol 0.56 mGy

DLP 9 mGy cm

Effective Dose 0.37 mSv*


Pitch 3.0


Slice width 1.0 mm


Reconstruction kernel B60f

Postprocessing syngo CT 3D

syngo InSpace

7 Volume rendered image of the thorax, showing regular bronchial tree.

7

6 Regular scan – sagittal image shows motion artifact of the diaphragm due to breathing during the acquisition.

5 High pitch scan – sharp delineation of pulmonary segments.

5 6 COMMENTSBecause of motion, the previous CT scan made diagnosis more difficult (Figs. 2, 4, 6). The fast acquisition speed made it possible to reliably rule out the presence of pulmonary infiltrations and mycosis. Although only 10 mAs were utilized, a high diagnostic image quality was pre-served. Using the new high pitch scanning technique a significant re-duction of radiation dose is feasible.

*Effective Dose was calculated using the published conversion factor for an 5-year-old pediatric chest of 0.082 mSv (mGy cm)-1 [1]. To take into account that Siemens calculates the CTDI in a 32 cm CTDI phantom an additional correction factor of 2 had to be applied.[1] McCollough CH et al. Strategies for Reducing Radiation Dose in CT, Radiol. Clin. N. Am. 47: (2009) 27-40.



Science

CT in Pediatrics: Easier and Safer With the FlashThe SOMATOM Defi nition Flash allows even squirming infants and small children to be scanned with maximum image quality at lightning speed, without movement artifacts, anesthesia, or ventilation. This makes computed tomography increasingly interesting for pediatric diagnostics, solely in the event of clear indications.

By Hildegard Kaulen, PhD

Being able to “freeze” movements in order to scan small children without seda-tion is every radiologist’s dream. Anesthe-sia transforms what would be a compar-atively fast scan into a time-consuming, possibly risky affair. Therefore, Michael Lell, MD, Assistant Professor at the Uni-versity Hospital in Erlangen, is extremely satisfied with the various pediatric options offered by the new SOMATOM Definition Flash. As small patients are moved through the tube at a speed of almost half a meter per second, they no

longer have to hold their breath or lie still for protracted periods. Sedation is no longer necessary either, and, as a result, the entire imaging process is re-duced to a few minutes. Lell has been working with the Flash for 16 months. During this period, he has successfully scanned 50 infants and toddlers, and the same number of children and ado-lescents, without sedation or anesthe-sia. His experience with the Flash in the field of pediatric diagnostics is out-standing. Says Lell: “The image quality

attained without sedation impresses us time and again. This is particularly strik-ing during a direct comparison between the Flash and another CT. We examined a 15-month-old child with Down’s syn-drome and cystic fibrosis using a 10-row CT. The images contained movement artifacts despite sedation. We examined the child once more at 27 months, this time using the Flash. The results? Razor-sharp images without sedation (Fig.1). One child even attempted to sit up dur-ing the scan. Everyone was convinced

1 Thorax CT scan for lung investigation of a 15-month-old child with cystic fibrosis with a 10-slice CT (Fig. 1A) and for follow-up 12 months later with the SOMATOM Definition Flash (Fig. 1B) showing artifact-free lung tissue.

1A 1B



Science

that the images would be blurred, but this wasn’t the case.”Young patients are usually examined using ultrasound or MRI devices. Children undergoing an MRI must be sedated. Lell comments: “Anesthesia and ventila-tion necessitate considerable time and effort. We are dependent on assistance from other specialist disciplines. The an-esthetic must be induced, controlled and reversed by an anesthetist, and the chil-dren have to be monitored for several hours afterward. Whereas scanning time is relatively short, outpatient care is nec-essary for hours.” Medical treatment, care and logistics result in substantial costs, and the associated risks can also be considerable. Anesthesia is an inva-sive procedure. Complications may arise at any time. Says Lell: “Ventilation also leads to anesthesia-related pulmonary atelectasis, a condition which causes parts of the lungs to collapse, impeding gas exchange. It is difficult to assess these areas accurately during imaging. This is-sue becomes irrelevant if anesthesia and

ventilation are not used. If it’s a choice between performing CT with anesthesia or not, then the answer in the case of the Flash is a definite no.”

Setting New StandardsThe SOMATOM Definition Flash is able to freeze movements due to its unique speed. Scanning speeds of up to 45.8 cm per second with a temporal resolution of 75 ms ensure that complete chest scans of young patients can be recorded in 0.4 to 0.5 seconds. No other device is as fast. The Flash also sets new stan-dards when it comes to radiation expo-sure. The Adaptive Dose Shield reduces radiation exposure in every single spiral scan. But the most impressive dose re-duction is possible in the field of cardiol-ogy where ultrafast Flash Spiral cuts down radiation compared to conventional ECG-gated examinations by up to 90 %. Lell believes that the Flash will make CT scans an increasingly attractive option for younger patients. The radiologist considers indications to be the decisive factor. In pediatrics, a CT would only be considered in the event of medical indi-cations with few or no alternatives, such as polytrauma or tumor staging. In the case of multiple injuries, it is more im-portant to clarify the extent of the trauma suffered than to contemplate a statistical increase in cancer risk in the distant future. Says Lell: “Some indications neces-sitate a CT examination, even if we are aware of the effective dose. We don’t know exactly how this dose may affect the cancer risk in any case as no long-term data is available based on medical imaging exposure levels.” Lell already insists on reduced dose protocols. He and his team have developed protocols like these for all pediatric indications. In Erlangen, children are always scanned with a tube voltage of 80 or 100 kV. Special anatomy adapted cushions are used to fix the small patients during the examination. Contrast agents are used very sparingly. Lell also ensures that the examination area is kept to a minimum, and strives to achieve the attention to detail necessary for diagnosis.

Hildegard Kaulen, PhD, is a molecular biolo-gist. After stints at the Rockefeller University in New York and the Harvard Medical School in Boston, she moved to the field of freelance science journalism in the mid-1990s and contrib-utes to numerous reputable daily newspapers and scientific journals.

Assistant Professor Michael Lell, MD, completed his medical studies at the universities of Regensburg and Munich with subsequent qualifica-tion as a consultant in radiology and habilitation. Employed by the Univer-sity Hospital in Erlangen since 1999. Promoted to Chief Physician in 2009. One-year residency at the David Steffen School of Medicine at UCLA. Member of national and international professional associations; reviewer for various journals.

Indications for Pediatric CT Scans:

PolytraumaCongenital heart diseaseSerious lung diseases such as cystic fibrosis or atypical pneumonias

Tumor staging

Benefits of Flash CTin Pediatrics:

Images free of movement arti-facts, even in the case of squirming children

No sedation or deep general anesthesia

Imaging possible without assis-tance from other disciplines such as anesthesia or nursing

No outpatient care or aftercare No complications as a result of anesthesia



Science

Through the use of a SOMATOM Emotion 6 from Siemens Healthcare, an international research team discovered atherosclerosis in 3500 year old Egyptian mummies.

A team of cardiologists led by Drs. Gregory S. Thomas of the University of California, Irvine and Adel H. Allam of Al Azhar University, Cairo, found that atherosclerosis is not only a disease of modern man, but was present in humans as far back as 1,530 BC. The team of cardiologists working closely with a team of Egyptologists undertook the most comprehensive CT study of vascular disease in Egyptian mummies to date by scanning 22 mum-mies over a four-day period in the Cairo Museum of Antiquities. The study was co-sponsored by Siemens Healthcare and aimed to investigate whether atheroscle-rosis, the precursor of heart disease, is an affliction of modern man or whether this disease existed thousands of years ago.

Study Finds Atherosclerosis in 3,500 Year old Egyptian Mummies By Steven Bell, Business Unit CT, Siemens Healthcare, Forchheim, Germany

The imaging for this project was under-taken on a SOMATOM Emotion 6-slice configuration that was donated to the Museum as part of an earlier study in conjunction with National Geographic to image the famous mummified remains of King Tutankhamun. The researchers were able to locate and identify vascular tissue in 16 out of the 22 mummies imaged in this study. Of these 16, 9 had visible signs of arterial calcification, considered to be pathogno-monic of atherosclerosis, from which the researchers were able to conclude that atherosclerosis is not a disease exclusive to modern humans. Findings of calcifica-tion were made in men and women who lived between 1570 BC and 364 AD. The social status of most patients included in

the study was shown to be of an elevated nature, which may have contributed to the process of disease due to lifestyle issues. The main aim of this project was to identify the presence or absence of atherosclerosis in an ancient patient population, however, the study also offered prominent Egyptologists the opportunity to view the mummified remains of these patients in a way that was not damaging to these ancient artifacts, the protection of which is central to the thinking of all members of this research study. The results of this project were pub-lished in the November 18, 2009 edition of the JAMA and also presented at the November AHA Meeting in Orlando, Florida, USA.


SOMATOM Sessions · Mai 2010 · www.siemens.com/healthcare-magazine 65

“True multi-center trials on stroke assessment by CT Perfusion and opti-mization of patient management will only be possible once every ven-dor’s software de-livers the same perfusion maps.”

Kohsuke Kudo, MD, PhD, Iwate Medical University

Science

A study by an independent Japanese research group reported that Siemens CT Perfusion software syngo VPCT Neuro, using the maximum slope model to de-rive cerebral blood flow (CBF), delivered among the most accurate results in the assessment of stroke infarct size com-pared to other commercial software.1 Kohsuke Kudo, MD, PhD, from Iwate Medical University and his colleagues from five other universities in Japan used data of 10 stroke patients acquired with a four-detector-row scanner and applied different algorithms to generate CT Per-fusion maps, in particular CBF, cerebral blood volume (CBV) and mean transit time (MTT) or time to peak (TTP) maps: A – singular-value decomposition (SVD, CT Perfusion 3, GE Healthcare)B – inverse filter IF (Version 2.0, Hitachi Medical Systems)C – singular-value decomposition (SVD, Version 1.201, Philips Healthcare)D – maximum slope (MS, VA70A, Siemens Healthcare)E – box modular transfer function (bMTF, Ph 7, Toshiba Medical Systems).Kudo compared the perfusion maps with the results from free software (Perfusion Mismatch Analyzer, PMA) distributed by the Acute Stroke Imaging Standard-ization Group (ASIST) Japan that applies two well-documented deconvolution algorithms: standard singular-value de-composition (sSVD) and block-circulant singular-value decomposition (bSVD). sSVD and bSVD algorithms differ with re-spect to their sensitivity to contrast tracer delay effects. bSVD is considered the “gold standard” since it is relatively insen-sitive to tracer delay.Kudo found that commercial software could be classified in two groups: those giving similar results to the CBF maps obtained with sSVD (A, C, E) and those giving similar results to the CBF maps

Independent Validation of Perfusion Evaluation Software By Katharina Otani, PhD and Toshihide Itoh

Research Collaboration Development, Siemens Asahi Medical Technologies, Tokyo, Japan

obtained with bSVD (B, D). Abnormal MTT/TTP areas appeared larger than those in bSVD for maps of all commercial software (A, C, D, E) except for one ven-dor’s software (B). An editorial in the same journal issue commented:2 “The results of the study by Kudo et al.1 also support the use of the maximum slope method for CT perfusion post-processing. Indeed, a recent MR imaging study3 of

acute stroke patients reported higher posi-tive predictive values for infarction by using maximum slope-derived parameters (first moment, TTP), versus both delay-sensitive and delay-insensitive deconvolu-tion-derived parameters. These results highlight the delay-insensitive nature of perfusion maps derived from maximum-slope algorithms. At present, however, there remains insufficient evidence to sug-gest whether maximum-slope methods outperform delay-insensitive deconvolu-tion algorithms.” Kudo started working on standardization of perfusion software after he programmed his own software and discovered that his results differed not only from the results of one commercial software but that the results from all soft-ware packages also differed from each other. With Makoto Sasaki, MD, he set up ASIST Japan supported by a grant from the Japanese governement. ASIST Japan has introduced a color look-up table for perfu-sion maps. Kudo emphasizes that “true multicenter trials on stroke assessment by CT Perfusion and optimization of patient management will only be possible once every vendor’s software delivers the same perfusion maps”.In his study, Kudo used earlier perfusion software versions such as Siemens “Neuro PCT”. In the meantime however, Siemens has developed “syngo VPCT Neuro”, a vol-ume perfusion software that gives the op-tion to also apply a new tracer delay insen-sitive deconvolution algorithm in addition to the as well delay insensitive maximum slope model used in this study. Kudo is currently working on further multi-vendor comparison studies.

http://asist.umin.jp/index-e.htm

1 Kudo K, et al . Radiology. 2010 Jan; 254(1):200-9

2 Konstas A A, et al. Radiology, 2010; 254(1):22-25

3 Christensen S, et al. Stroke 2009, 40 : 2055 – 2061



Science

Reduced Procedure Time and Radiation Dose in Inter-ventional CT WorkflowBy Prof. A.H. Mahnken, MD and F. Schoth, MD

RWTH Aachen University Hospital, Aachen, Germany

Percutaneous lung biopsy is one of the most common CT-guided procedures. This technique can be performed using sequential CT-scanning or CT-fluoroscopy. Because CT-fluoroscopy may result in significant radiation exposure to the patient as well as the interventionalist, repeated sequential CT-scanning is com-mon practice due to the minimal radia-tion exposure to the operating physician. However, this approach requires several breath holds, with the target lesion mov-

ing during in- and expiration. For many patients, it is virtually impossible to re-peatedly come back to the same breath hold position. Therefore, small lesions in particular, will often move out of plane. This problem is particularly pro-nounced in the basal sections of the lung and is a major issue when dealing with small lesions of 1 cm or less.Combining CT-guided procedures with the Interactive Breath-Hold Control device (IBC) has been shown to increase

the radiologists’ accuracy and confidence with needle biopsy of the lung. A simple light display allows the patients to moni-tor their breathing level and consistently return to their reference breath-hold position during their biopsies. The IBC was developed to assist with CT inter-ventional procedures, but may also be very useful for PET CT, radiation therapy, ultrasound, fusion imaging, and other procedures and modalities where respi-ratory motion is an issue. At the depart-

1 The IBC system brings down the total procedure time. In this example, the time from placing the reference grid to harvesting three samples from a small lung nodule was less than 50 seconds.

1A 1B

45

60

15

30



Science

ment of Diagnostic Radiology, RWTH Aachen University Hospital in Germany, a study was conducted to evaluate the IBC system in CT-guided lung biopsy. Schoth and colleagues assessed the effect of an IBC system on procedure time and technical success in trans-thoracic CT-guided lung biopsies. In 36 patients with a pulmonary nodule, CT-guided biopsy was done using a SOMATOM Definition scanner, the Adaptive 3D Intervention Suite from Siemens and the breath-hold device. In a two-arm study with and without the device, the biopsy was visu-ally successful in all patients. The diame-ter of the target lesion was comparable in both groups (IBC: 30 +/– 19 mm; con-trol: 28 +/– 15 mm). But the number of imaging steps was significantly smaller (p < 0.05) and the intervention time was significantly shorter (p < 0.05) in the IBC group (IBC: 9 +/– 5 steps, 17 +/– 10 min; control: 13 +/– 5 steps, 26 +/– 12 min). Application of the IBC unit reduced the intervention time and radiation expo-

sure in CT-guided biopsy of pulmonary nodules while reducing the procedure steps. In combination with optimized planning using the new Adaptive 3D Intervention software from Siemens for 3D CT-guided interventions, biopsy of smaller nodules becomes much easier, resulting in a higher technical success rate. With the early detection and histological proof of lung cancer, treatment is more effective. Prognosis significantly improves when lung cancer is detected and treated be-fore metastases occur. Therefore, a high success rate of diagnostic punctures during the diagnostic workup greatly supports therapy. Moreover, IBC is a rele-vant support to therapeutic procedures such as radiofrequency ablation or ste-reotactic radiation therapy of small lung tumors.Regarding dose reduction, the IBC inte-grates and supplements perfectly into the huge expertise that Siemens has accumulated to reduce radiation dose in

CT-guided examinations with such appli-cations as CARE Dose4D and HandCARE, protecting patients and physicians from radiation exposure during CT interven-tions.

Schoth F, Plumhans C, Kraemer N, Mahnken A,

Friebe M, Günther RW, Krombach G. – Evaluation

of an Interactive Breath-Hold Control System

in CT-Guided Lung Biopsy. Rofo. 2010 Feb 8.

2 Combining CT-guided procedures with the Interactive Breath-Hold Control device (IBC) has been shown to increase the radiologists’ accuracy and confidence with needle biopsy of the lung.

2

3 Interactive Breath-Hold Control System was developed by Mayo Clinic Rochester, USA to assist CT-guided interventional procedures.*

3

* The device will be distributed by Medspira (USA) (www.medspira.com) and Siemens AG.



Science

Since the introduction of the Siemens SOMATOM Definition Flash at RSNA 2008, and its commercial availability in July 2009, the CT scanner has been cov-ered in 15 presentations at the annual meeting of the Radiological Society of North America in 2009 and ten peer-reviewed publications in renowned journals.These presentations and publications prominently feature the notable advan-tages of the SOMATOM Definition Flash that enhance efficiency and significantly improve patient care.

Split-second Thorax – Lell et al. from the University Hospital of Erlangen dem-onstrated the SOMATOM Definition Flash’s capabilities with its high-pitch scan mode in thorax examinations.1 Twenty-four consecutive patients who presented with chest pain received a high-pitch thorax scan (Pitch 3.2) to exclude coronary artery disease, pulmo-nary embolism and aortic dissection. The average dose was 1.6 mSv for pa-tients who were scanned with a 100 kV protocol and 3.2 mSv for patients who were scanned with a 120 kV protocol. The authors conclude that the “[…] high-pitch scan mode allows motion artifact free and accurate visualization of the thoracic vessels and diagnostic image quality of the coronary arteries in pa-tients with low and stable heart rates at a very low radiation exposure.”

Scientifi c Validation of the SOMATOM Defi nition Flash One of the cornerstones of Siemens CT activities has always been the scientifi c validation of Siemens’ products and solutions. Independent peer-review of publications in scientifi c journals provides an unbiased and objective assessment of the capabilities of the systems.

By Stefan Ulzheimer, PhD, and Peter Seitz


The dose saving potential of the high-pitch scan mode of SOMATOM Definition Flash was also evaluated by Sommer et al. in a study using an anthropomorphic phantom and the data of 31 patients.2 The average scan time for the complete thorax was 0.7 seconds, the average dose 4.1 mSv, only one fifth of the dose of a conventional gated chest scan.

Sub-mSv Heart – The robust visualiza-tion of the coronary arteries with excel-lent image quality at ultra low doses of below 1 mSv was the focus of three pub-lications by researchers from Zurich, Switzerland3 and Erlangen, Germany.4,5 The latest study from Erlangen used the Flash Spiral scan mode in 50 consecutive patients with body weight up to 100 kg and heart rates up to 60 beats per min-ute with an average effective dose of 0.78 to 0.99 mSv and excellent image quality.5 The average dose was 0.87 mSv. In a similar study from Zurich, Leschka et al. found an average dose of 0.9 mSv in 35 consecutive patients.3 In both studies 99% of all coronary seg-ments could be evaluated3,5 and the im-age quality was rated excellent in 94 % of the segments or as, “at least good,” in 5 % of the segments.5

Assessment of Myocardial Perfusion – The SOMATOM Definition Flash offers completely new possibilities to assess perfusion deficits in the myocardium

due to its unmatched temporal resolu-tion and high volume coverage even at high heart rates in stressed patients. Bastarrika et al. showed that “[…] this technique can demonstrate subendocar-dial infarction not seen on SPECT but confirmed by MRI and can detect isch-emia in good correlation with stress-perfusion MRI and SPECT.” 6 Fig. 1 shows a short axis view of the myocardium comparing stress perfusion measured with the SOMATOM Definition Flash (Fig. 1A) and SPECT (Fig. 1B).

Single Dose Dual Energy – The latest innovation in the area of Dual Energy CT (DECT), the Selective Photon Shield, is based on an additional tin filter (TF) for the high energy spectrum on the SOMATOM Definition Flash. The Selec-tive Photon Shield allows for the acquisi-tion of Dual Energy data without any dose penalty compared to standard single energy scans and significantly improves the separation of the energy spectra. A group of scientists from Zurich con-firmed this for the syngo application, “Calculi Characterization,” using it for the differentiation of uric acid (UA) and non-UA stones and concluded: “DECT with TF and 80-140 kV tube voltage settings significantly improves the discrimination between UA-containing and non-UA containing urinary stones as compared with DECT without using the TF […].”7

Lell et al. from the University of Erlangen



Science

evaluated the application of DECT to create bone-free data sets to assess the supraaortic arteries.8 Automatic bone removal allows for a faster and more re-liable diagnosis of vessels close to boney structures. The authors conclude that “[…] excellent bone suppression could be achieved” using the improved scan modes and evaluation methods on the SOMATOM Definition Flash. By combining multi-phase protocols to one Dual Energy exam, the dose-saving potential of DECT was evaluated by Sommer et al. in patients after endovas-cular aneurism repair using virtual non-contrast images. They achieved a dose reduction of 44 % compared to a bi-phase protocol. In 70 examinations, all 24 endoleaks were detected and correctly classified.9

More to Come – In addition to the above mentioned publications, many others are in the pipeline, promising to validate the technical advancements of the SOMATOM Definition Flash and, even more importantly, how this trans-lates into clinical and workflow advan-

1 Lell M, Hinkmann F, Anders K, Deak P, Kalender

WA, Uder M, Achenbach S. High-pitch electro-

cardiogram-triggered computed tomography of

the chest: initial results, Invest Radiol. 2009

Nov;44(11):728-33.

2 Sommer WH, Schenzle JC, Becker CR, Nikolaou

K, Graser A, Michalski G, Neumaier K, Reiser MF,

Johnson TR. Saving Dose in Triple-Rule-Out Com-

puted Tomography Examination Using a High-

Pitch Dual Spiral Technique. Invest Radiol. 2010

Feb;45(2):64-71.

3 Leschka S, Stolzmann P, Desbiolles L, Baumueller

S, Goetti R, Schertler T, Scheffel H, Plass A, Falk V,

Feuchtner G, Marincek B, Alkadhi H. Diagnostic

accuracy of high-pitch dual-source CT for the

assessment of coronary stenoses: first experience.

Eur Radiol. 2009 Dec;19(12):2896-903.

4 Lell M, Marwan M, Schepis T, Pflederer T, Anders

K, Flohr T, Allmendinger T, Kalender W, Ertel D,

Thierfelder C, Kuettner A, Ropers D, Daniel WG,

Achenbach S. Prospectively ECG-triggered high-

pitch spiral acquisition for coronary CT Angiogra-

phy using dual source CT: technique and initial

experience. Eur Radiol. 2009 Nov;19(11):2576-83.

5 Achenbach S, Marwan M, Ropers D, Schepis T,

Pflederer T, Anders K, Kuettner A, Daniel WG,

1 New frontiers in cardiac diagnosis with CT: stress-perfusion images of the heart using the unmatched temporal resolution of the SOMATOM Definition Flash compared to SPECT. A stress perfusion scan on the SOMATOM Definition Flash nicely depicts a perfusion defect in the myocardium (Fig. 1A). The perfusion defect could be confirmed using SPECT (arrows, Fig. 1B). Courtesy of Joseph Schoepf, MD, Medical University of South Carolina, USA.

tages. For example, a special issue of “Investigative Radiology” on “Advances in CT technology,” specifically focusing on Dual Source, Dual Energy CT and multi-slice CT with 128 or more slices, is scheduled for this summer.

Uder M, Lell MM. Coronary computed tomogra-

phy angiography with a consistent dose below

1 mSv using prospectively electrocardiogram-

triggered high-pitch spiral acquisition. Eur Heart

J. 2010 Feb;31(3):340-6.

6 Bastarrika G, Ramos-Duran L, Schoepf UJ, Rosen-

blum MA, Abro JA, Brothers RL, Zubieta JL, Chia-

ramida SA, Kang DK Adenosine-stress dynamic

myocardial volume perfusion imaging with sec-

ond generation dual-source computed tomogra-

phy: Concepts and first experiences. JCCT 2010

DOI: 10.1016/j.jcct.2010.01.015.

7 Stolzmann P, Leschka S, Scheffel H, Rentsch K,

Baumüller S, Desbiolles L, Schmidt B, Marincek

B, Alkadhi H. Characterization of Urinary Stones

With Dual-Energy CT: Improved Differentiation

Using a Tin Filter. Invest Radiol. 2010 Jan;

45(1):1-6.

8 Lell M, Hinkmann F, Nkenke E, Schmidt B,

Seidensticker P, Kalender WA, Uder M, Achenbach

S. Dual energy CTA of the supraaortic arteries:

Technical improvements with a novel dual

source CT system. Eur J Radiol. 2009 Oct 8

[Epub ahead of print].

9 Sommer WH, Graser A, Becker CR, Clevert DA,

Reiser MF, Nikolaou K, Johnson TR. Image quality

of virtual noncontrast images derived from dual-

energy CT Angiography after endovascular

aneurysm repair. J Vasc Interv Radiol. 2010 Mar;

21(3):315-21.

10 Johnson TR, Schenzle JC, Sommer WH, Michalski

G, Neumaier K, Lechel U, Nikolaou K, Becker H-C,

Reiser MF. Dual energy CT: How about the dose?

Invest Radiol. 2010 (in press).

1B1A



How would you describe your job as a scan protocol designer? Koch: My task is to create scan protocols for all scanners and all software ver-sions. Together with colleagues from departments of physics, product defini-tion, marketing, development and the application specialists, I design and set up Siemens default scan protocols. In doing so, dose and other guidelines of various radiological societies from different countries need to be observed. Scan protocols have to be comparable through different software versions and scanner models. For example a protocol called “AbdomenRoutine” on a SOMATOM Emotion is similar to the protocol on a SOMATOM Definition. I consolidate the data for the scan proto-cols in a comprehensive data base. These files become translated to a data-base called, “ModeLibrary”, and after-wards as usable scan protocol to the user interface.I am in close collaboration with custom-ers and application specialists world-wide, both during the development phase and after systems are installed.

How do you validate scan protocols before a new scanner is released?Koch: Functionality and performance are tested with phantoms in our laboratory during the development phase. For intui-tive tests, we do invite Radiographers in order to simulate a real live scenario.

What is important to know when users want to change parameters in a default scan protocol?Koch: Around 50% of all scan protocol parameters run in the background. These parameters are, for example, dose modulation types and additional recon-struction algorithms. It would be ideal if our customers would use the default pro-tocols. In this manner, following the

Christiane Koch is the scan protocol designer for Siemens CT.

Life

Behind the Scenes: CT Scan ProtocolsStandard scan protocols are by far more sophisticated than CT users might realize. Christiane Koch is the scan protocol designer for Siemens Healthcare, Computed Tomography and knows what is important in this fi eld.

By Heike Theessen


This is all done before new scanners are delivered to any customer. Then, during the so-called “Market Entrance Phase”, our collaboration partners begin scan-ning patients and the scan protocols are clinically tested. The results are reviewed and validated by radiologists and physi-cists. Before the new CT system is finally released, scan protocols are adapted according to the results of all prior tests.



ALARA principle, the best possible image quality at the lowest possible dose can be achieved. But, of course, all users need to adapt certain parameters to fit their individual needs such as breathing instructions for the patient or transfer rules indicating where images should be sent. If the operator wants to change any parameters within a scan protocol, it is important to select the correct base pro-tocol. For example an “AbdomenRou-tine” protocol should not be changed to fit a neck examination and vice versa. Also, if an institute has scanners from different vendors or different scanner models, tube current values can not be compared when it comes to dose. Only the CTDIvol value represents a compara-ble figure. The CTDIvol is a measured value of the dose absorbed during a CT examination.

Dedicated children protocols are pro-vided on all Siemens CT scanners. What is so special about these protocols?Koch: Children scan protocols are devel-oped in cooperation with pediatric radiologists in order to ensure even lower dose values as compared to adult protocols. By using children protocols, the user does not have to adjust dose values to the age or weight of the child. In these protocols, CARE Dose4D auto-matically adapts the tube current to the individual patient’s anatomical charac-

teristics. However, children older than 6 years or heavier than 55 kg can be examined with regular adult protocols. Fast scan times are very helpful when scanning children since they probably will not, or cannot, hold still for the duration of the scan. An increased pitch value or faster rotation time also sup-port fast acquisitions. Repeated scan-ning can be avoided.

Where can users find more informa-tion about CT scan protocols?Koch: The Workflow Assistant is included within the CT Life Card. It is available for the SOMATOM Definition family starting with software version syngo CT 2007B (VA11). Application Guides do exist for older scanner models. These media include valuable facts about scan proto-cols, physical fundamentals, dose mea-sures and practical tips and tricks.

Life

Do not use a protocol from a cer-tain body region and change it to a protocol to fit another body region.

When comparing dose values of different scanner models and different vendors, it is important to compare CTDIvol values, not tube current values. Tube current values are related primarily to filter settings and the scanner geometry.

Customized scan protocols can be exported through the Scan Proto-col Assistant to Excel to be used on a PC for further documentation, e.g. documentation of dose values.

All or certain scan protocols can be copied from one scanner to another scanner via the Scan Pro-tocol Assistant. Pre-conditions are the same scanner model and iden-tical software version.

Tips from the expert:

www.siemens.com/life-courses

Data for the scan protocols are being consolidated in a comprehensive data base.

“The best possible image quality at the lowest dose can be achieved by using the default scan protocols.”Christiane Koch, Business Unit CT, Siemens Healthcare, Forchheim, Germany.



Life

For the 6th consecutive year, Siemens Healthcare offered hands-on workshops in the experience lounge at ECR 2010. Participants could benefit from very comprehensive sessions for CT, MR as well as PET and SPECT CT.Unlike previous years however, the new imaging software syngo.via* was used for the sessions CT Cardiology, CT Oncol-ogy and CT Colonography. During the 90 minute sessions, Tobias Pflederer, MD, from Erlangen University and Thomas

Mang, MD, from Vienna University, dem-onstrated how they can use syngo.via for their daily reporting. At the beginning of each session, a theo-retical introduction into the topic was given by the speakers. Pflederer pointed out the various dose reduction possibili-ties for Cardiac CT while Mang gave an overview of patient preparation and reading techniques for CT Colonography. After a brief demonstration of syngo.via by Siemens application specialists, the

participants could experience Siemens new imaging software for themselves. The instructing physicians guided them step-by-step through the applications, explaining the benefits of syngo.via. Customers particularly liked the auto-mated case preparation, where all coro-nary arteries are automatically labelled and functional evaluations for left and right ventricle are already done.Next workshops with syngo.via are planned for ESC 2010 in Stockholm.

First syngo.via Hands-on Workshops at ECR 2010By Heike Theessen, Business Unit CT, Siemens Healthcare, Forchheim, Germany

T. Mang, MD, hold the session on CT Colonography using syngo.via

Upcoming Events & Congresses

Title Location Short Description Date Contact

ASNR Boston, USA 48th Annual Meeting May 15-20, 2010 www.asnr.org

ISCT San Francisco, 12th International May 18–21, 2010 www.isct.org USA Symposium on Multidetector-Row CT

WCC Bejing, China World Congress of June 16–19, 2010 www.worldheart.org Cardiology Scientific Sessions 2010

SCCT Las Vegas, USA 5th Annual July 14–15, 2010 www.scct.org Scientific Meeting

ESC Stockholm, Cardiology August 28 – www.escardio.org Sweden Congress September 01, 2010

ESNR Bologna, Italy Neuroradiology October 04–09, 2010 www.esnr.org Congress

RSNA Chicago, USA Annual Meeting of November 28– www.rsna.org Radiological Society December 03, 2010 of North America

* syngo.via can be used as a standalone device or together with a variety of syngo.via based software options, which are medical devices in their own rights.


Life

Recent years have brought significant progress to the area of ischemic stroke therapy. Equally important develop-ments have taken place on the diagnos-tic side. With availability of Adaptive4D Spiral on all SOMATOM Definition scan-ners, coverage for perfusion imaging has been extended beyond the limita-tion of the detector size. Physicians can now adjust the coverage to the specific needs of the patient and the indications of the neurological exam. New syngo Volume Perfusion CT Neuro software offers improved guided workflow and enables rapid sharing of perfusion data and maps utilizing syngo Expert-i. In or-der to improve the knowledge on Sie-mens offerings in this area, Siemens USA

Siemens’ newest application for neuro-logical imaging, syngo Volume Perfusion CT Neuro, can now be tried for 90 days at no cost.syngo Volume Perfusion CT Neuro facili-tates quantitative 3D volume evaluation for differential diagnosis of brain tumors and ischemic stroke. In combination with Adaptive 4D Spiral technology, ex-tended brain coverage is feasible.* It is the most complete 3D stroke evaluation software on the market and the only ap-plication with both maximum slope and deconvolution models integrated, sup-porting diagnostic results even in critical situations. With the 3D Auto Stroke func-tionality, therapeutic decisions can be made without complex user interac-

has launched a dedicated website: https://www.med.usa.siemens.com/stroke. Particularly beneficial is the three part Webcast presented by Ke Lin, MD, from New York University: https://www.med.usa.siemens.com/stroke/webcast/Part 1: Appropriateness of perfusion in stroke diagnosis: Where and when to use it.Part 2: Workflow, Acquisition and Post Processing. Part 3: How to read and interpret studies.Siemens is also working closely with Ap-plied Radiology: http://www.appliedradi-ology.com/ on an educational stroke forum that will further discuss the diverse needs of the stroke teams at the clinics and particularly emphasize the beneficial

tions. All relevant perfusion parameters (CBF, CBV, TTP, MTT) are shown in one view. The integrated “3D Tissue at Risk Evaluation” gives confidence in the dif-ferentiation between cerebral tissue at risk and core infarct. All these features make syngo Volume Perfusion CT Neuro night shift and 24/7 service ready.

Training Website for Knowledge Improvement

Free Trial Licenses for Neuro Imaging

By Jakub Mochon, Computed Tomography Division, Siemens Medical Solutions, Malvern, Pennsylvania, USA

By Marion Meusel, Business Unit CT, Siemens Healthcare, Forchheim, Germany

In order to improve the knowledge on Siemens offerings, Siemens USA has launched a dedicated website https://www.med.usa.siemens.com/stroke

syngo Volume Perfusion CT Neuro – All dynamic informa-tion in one view.

International: www.siemens.com/DiscoverCTUSA only: www.usa.siemens.com/webShop/CT

Similar free-trial licenses are available for many more clinical applications.

*Available for the SOMATOM Definition family only.

role and utility of CT imaging in stroke care.


Siemens Healthcare will offer a work-shop on Dual Energy CT in cooperation with Thorsten Johnson, MD, Associate Professor of Radiology and Head of Com-puted Tomography at Munich University Hospital, Campus Großhadern, Germany. The course will take place in Forchheim, Germany from September 10th to Sep-tember 11th 2010.The field of Dual Energy CT scanning is expanding incredibly fast. Twelve dif-ferent FDA cleared Dual Energy applica-tions have already been introduced since the launch of Dual Source CT in 2005, creating both clinical and educational demand. Siemens Healthcare will provide a comprehensive overview to those who are just starting to integrate Dual Energy CT into their daily routine with emphasis on understanding the principles and fully

In the Scan Protocol Assistant (SPA), the user has access to all scan protocols. These protocols can be adapted, changed or deleted. Everything is clearly listed as in the patient model dialog. The layout is comparable to the examination

utilizing the potential of Dual Energy CT. The two-day training session will include presentations on both the physical princi-ples and the clinical benefits of Dual Energy CT. A hands-on session at a SOMATOM Definition scanner, as well as on a workstation for extended case re-view is also part of the workshop. “Some of the things covered in the workshop

card, which makes it easy to find the entries which should be changed.How can SPA help in daily routine? 1. The entry “CTDIvol”, for example, can be added for all scan protocols as follows: First the SPA has to be opened, via

Dual Energy CT: Learning From the ExpertsBy Heike Theessen, Business Unit CT, Siemens Healthcare, Forchheim, Germany

Frequently Asked QuestionsBy Ivo Driesser, Business Unit CT, Siemens Healthcare, Forchheim, Germany

“Options”, “Configuration” and “Scan Protocol Assistant”. Step 1: Select “Change Protocols.” Step 2: Select all protocols. Step 3: Go to “scan” where you see all the scan parameters. Click on the config-uration icon (marked in red on the im-age). Select the “CTDIvol” box and place in the menu bar via the arrow (marked in green). Click on the configuration icon again. If desired the“CTDIvol” entry can be selected in the menu bar and moved to the preferred location.2. For 3D reconstructions it is preferable to have a non-square matrix. Select in Step 2 all the affected protocols by using the filter “3D recon jobs”. In in Step 3 you can change the matrix size. Select the column “Matrix size” and in the l ower part, make your changes. All selected protocols will now be changed.In this way, protocols are easily and quickly adapted to the users preferences.

have been used reliably in daily routine for years. Some others are only a couple of months old. Upon completion of the workshop, participants will be at the fore-front of Dual Energy technology,” says course director Johnson.

During a workshop Thorsten Johnson, MD

will present both the physical principles

and clinical benefits of Dual Energy CT.

www.siemens.com/life-courses

Example of the Trigger card of SOMATOM Definition scanner.




Life


Clinical Workshops 2010As a cooperation partner of many renowned hospitals,

Siemens Healthcare offers continuing CT training programs. A wide range of clinical workshops keeps participants at

the forefront of clinical CT imaging.

In addition, you can always fi nd the latest CT courses offered by Siemens Healthcare at www.siemens.com/SOMATOMEducate

Workshop Title Dates Location Course Course language director

Clinical Workshop on July, 28–30 2010 Erlangen, English Prof. Stephan Achenbach, MDCardiac CT / Erlangen Germany

Clinical Workshop on July, 07–09 2010 Munich, English PD Konstantin Nikolaou, MDCardiac CT / Munich December, Germany Prof. Christoph Becker, MD 15 –17 2010 Alexander Becker, MD

Clinical CTA Interpretation November, Erlangen, English Prof. Stephan Achenbach, MD Course / Erlangen 18–19 2010 Germany

Hands-on Workshop September, St. Gallen, German PD Hatem Alkadhi, MDCardiac CT 23–25 2010 Switzerland PD Sebastian Leschka, MD

Clinical Training Course June, 26–27 2010 Kuching, English Prof. Sim Kui Hian, MD on Cardiac CT October, 30–31 2010 Malaysia Ong Tiong Kiam, MD

Virtual CT-Colonography June, 11–12 2010 Berlin, German Prof. Bernd Lünstedt, MD November, 05–06 2010 Germany

Dual Energy Workshop September, Forchheim, English PD Thorsten Johnson, MD 10 –11 2010 Germany

ESGAR CT-Colonography September, Lisbon (Cascais), English Workshops 23–24 2010 Portugal Prof. Filippe Caseiro-Alves, MD April Dublin, Prof. Helen Fenlon, MD 13–15, 2011 Ireland Martina Morrin, MD September Gothenburg, Prof. Mikael Hellström, MD 14 –16, 2011 Sweden

Cardiac-CT Workshop/ Autumn 2010 Dubai, UAE English PD Christoph Becker, MD Dubai Alexander Becker, MD

Hands-on Workshops August, Stockholm, English n.a.during ESC 2010 28 –31 2010 Sweden

Experience Lounge November, 28 – Chicago, English n.a.at RSNA 2010 December, 2 2010 USA


Siemens Healthcare – Customer MagazinesOur customer magazine family offers the latest information and background for every healthcare fi eld. From the hospital director to the radiological assistant – here, you can quickly fi nd information relevant to your needs.

For current and prior issues and to order the magazines, please visit www.siemens.com/healthcare-magazine

Medical SolutionsInnovation and trends in healthcare. The magazine, published three times a year, is designed especially for members of the hospital management, administration per-sonnel, and heads of medical departments.

AXIOM InnovationsEverything from the worlds of interventional radiology, cardiology, fluoroscopy, and radiography. This semi-annual magazine is primar-ily designed for physicians, physicists, researchers, and medical technical personnel.

MAGNETOM FlashEverything from the world of magnetic resonance imaging. The magazine presents case reports, technology, product news, and how-to’s. It is primarily designed for physicians, physicists, and medical technical personnel.

SOMATOM SessionsEverything from the world of computed tomography. With its innovations, clinical applications, and visions, this semiannual magazine is primarily designed for physicians, physicists, researchers, and medical technical personnel.

PerspectivesEverything from the world of clinical diagnostics. This semi-annual publication pro-vides clinical labs with diag-nostic trends, technical inno-vations, and case studies. It is primarily designed for laboratorians, clinicians and medical technical personnel.

The Magazine for Healthcare Leadership

May 2010

Medical Solutions

Medicine in 2050How today’s babies will grow into the future of healthcare

Inhalt_May_10_eng.indd 1 23.04.10 09:10

NewsOur latest topics such as product news, reference stories, reports, and general interest topics are always available at www.siemens.com/healthcare-news


Life


“Neuro BestContrast allows radiologists to better visualize subtle edemas as well as subtle signs of stroke, and to better delineate the cortical margin.”

David S. Enterline, MD, Duke University Medical Center in Durham, North Carolina, USA

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Responsible for Contents: André Hartung

Editorial Board: Andreas BlahaHelge BohnAndreas FischerThomas Flohr, PhDJulia HoelscherKlaudija IvkovicAxel LorzPeter SeitzStefan Ulzheimer, PhDAlexander Zimmermann

Authors of this IssueH. Alkadhi, MD, Institute of Diagnostic Radiology, University Hospital Zurich, Zurich, Switzerland

F. Bamberg, MD, Department of Clinical Radiology, University of Munich, Campus Großhadern, Munich, Germany

R. W. Bauer, MD, Department of Diagnostic and Interventional Radiology, Clinic of the Goethe University, Frankfurt, Germany

Note in accordance with § 33 Para.1 of the German Federal Data Protection Law: Despatch is made using an address file which is maintained with the aid of an automated data processing system.SOMATOM Sessions with a total circulation of 35,000 copies is sent free of charge to Siemens Computed Tomography customers, qualified physicians and radiology departments throughout the world. It includes reports in the English language on Computed Tomography: diagnostic and therapeutic methods and their applica-tion as well as results and experience gained with corresponding systems and solutions. It introduces from case to case new principles and procedures and dis-cusses their clinical potential.The statements and views of the authors in the individual contributions do not necessarily reflect the opinion of the publisher.The information presented in these articles and case reports is for illustration only and is not intended to be relied upon by the reader for instruction as to the prac-tice of medicine. Any health care practitioner reading this information is remind-ed that they must use their own learning, training and expertise in dealing with their individual patients. This material does not substitute for that duty and is not intended by Siemens Medical Solutions to be used for any purpose in that regard.

A. Becker, MD, Department of Clinical Radiology, University of Munich, Campus Großhadern, Munich, Germany

C. R. Becker, MD, Department of Clinical Radiology, University of Munich, Campus Großhadern, Munich, Germany

G. Feuchtner, MD, Institute of Diagnostic Radiolo-gy, University Hospital Zurich, Zurich, Switzerland

M. Fischer, MD, Institute of Diagnostic Radiology, University Hospital Zurich, Zurich, Switzerland

R. Goetti, MD, Institute of Diagnostic Radiology, University Hospital Zurich, Zurich, Switzerland

W. Heindel, MD, Department of Clinical Radiology, University Hospital, Münster, Germany

J. M. Kerl, MD, Department of Diagnostic and Interventional Radiology, Clinic of the Goethe University, Frankfurt, Germany

M. Lell, MD, Department of Radiology and the Imaging Science Institute (ISI), University of Erlangen-Nuremberg, Erlangen, Germany

S. Leschka, MD, Institute of Diagnostic Radiology, University Hospital Zurich, Zurich, Switzerland

K. Lin, MD, Department of Radiology, New York University Langone Medical Center, New York, NY, USA

A. H. Mahnken, MD, RWTH Aachen University Hospital, Aachen, Germany

Y. Mizutani, MD, Department of Radiology, Sakakibara Heart Institute, Tokyo, Japan

K. Nikolaou, MD, Department of Clinical Radiology, University of Munich, Campus Großhadern, Munich, Germany

J.-F. Paul, MD, Centre Chirurgical Marie Lannelongue, Le Plessis-Robinson, France

A. Plass, MD, Clinic of Cardiovascular Surgery, University Hospital Zurich, Zurich, Switzerland

B. Policeni, MD, Radiology Faculty, Neuroradiology, University of Iowa Hospitals and Clinics, Iowa City, Iowa, USA

H. Scheffel, MD, Institute of Diagnostic Radiology, University Hospital Zurich, Zurich, Switzerland

F. Schoth, MD, RWTH Aachen University Hospital, Aachen, Germany

F. Schwarz, MD, Department of Clinical Radiology, University of Munich, Campus Großhadern, Munich, Germany

H. Seifarth, MD, Department of Clinical Radiology, University Hospital, Münster, Germany

K. Takada, MD, Department of Radiology, Sakakibara Heart Institute, Tokyo, Japan

T. J. Vogl, MD, Department of Diagnostic and Interventional Radiology, Clinic of the Goethe Uni-versity, Frankfurt, Germany

P. Weisser, MD, Department of Diagnostic and In-terventional Radiology, Clinic of the Goethe University, Frankfurt, Germany

M. Wieser, MD, Clinic of Cardiovascular Surgery, University Hospital Zurich, Zurich, Switzerland

C. Wyss, MD, Cardiology Division, University Hospital Zurich, Zurich, Switzerland

Sameh Fahmy, freelance medical and technology journalist Tony DeLisa, freelance authorWiebke Kathmann, PhD, freelance scientific journalistHildegard Kaulen, PhD, freelance scientific journalistOliver Klaffke, freelance scientific journalistAnnette Tuffs, MD, medical journalist

Peter Aulbach; Karin Barthel; Andreas Blaha; Steven Bell; Ivo Driesser; Kerstin Fellenzer; Tomoko Fujihara; Jan Freund; Tanja Gassert; Toshihide Itoh; Christiane Koch, Rami Kusama; Marion Meusel; Jakub Mochon; Katharina Otani, PhD; Kerstin Putzer; Heike Theessen; Peter Seitz; Ste-fan Ulzheimer PhD; Fernando Vega-Higuera; Stefan Wünsch, PhD; all Siemens Healthcare

Photo Credits: Greg Morris, Yohanne Lamoulére/Agentur Focus, Harald Krieg, Thorsten Rother

Production: Norbert Moser, Siemens AG, Medical Solutions

Design and Editorial Consulting: Independent Medien-Design, Munich, GermanyIn cooperation with Primafila AG, Zurich, Switzerland; Managing Editor: Christa Löberbauer; Photo Editor: Susanne Nips; Layout: Claudia Diem, Mathias Frisch; All at: Widenmayerstraße 16, 80538 Munich, Germany

The drugs and doses mentioned herein are consistent with the approval labeling for uses and/or indications of the drug. The treating physician bears the sole responsibility for the diagnosis and treatment of patients, including drugs and doses prescribed in connection with such use. The Operating Instructions must always be strictly followed when operating the CT System. The sources for the technical data are the corresponding data sheets. Results may vary.Partial reproduction in printed form of individual contributions is permitted, pro-vided the customary bibliographical data such as author’s name and title of the contribution as well as year, issue number and pages of SOMATOM Sessions are named, but the editors request that two copies be sent to them. The written consent of the authors and publisher is required for the complete reprinting of an article.We welcome your questions and comments about the editorial content of SOMATOM Sessions. Manuscripts as well as suggestions, proposals and informa-tion are always welcome; they are carefully examined and submitted to the edito-rial board for attention. SOMATOM Sessions is not responsible for loss, damage, or any other injury to unsolicited manuscripts or other materials. We reserve the right to edit for clarity, accuracy, and space. Include your name, address, and phone number and send to the editors, address above.

SOMATOM Sessions – IMPRINT© 2010 by Siemens AG, Berlin and MunichAll Rights Reserved

Publisher:Siemens AGHealthcare SectorBusiness Unit Computed TomographySiemensstraße 1, 91301 Forchheim, Germany

Monika Demuth, PhD ([email protected])

Stefan Wünsch, PhD([email protected])


Imprint


Editorial

“Our new neurological software combined with the SOMATOM Defi nition line of scanners repre-sents a quantum leap in speed, low dose and diagnostic accuracy.”

Sami Atiya, PhD, Chief Executive Officer, Business Unit Computed Tomography, Siemens Healthcare, Forchheim, Germany

Cover Page: With Volume Perfusion CT Neuro fused with carotid CT Angiography the perfusion status of the brain tissue can be observed. Courtesy of University Hospital Göttingen, Germany.

Chief Editors:

SOMATOM Sessions is also available on the internet: www.siemens.com/SOMATOMWorld


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sRapid evaluation is critical after trauma and with symptoms such as weakness, headache, and dizziness, which is why CT is the modality of choice in these scenarios. Exceptional image quality is key to optimize diagnosis, and lower dose imaging minimizes risk to the patient.

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Issue Number 26/May 2010International Edition

On account of certain regional limitations of sales rights and service availability, we cannot guarantee that all products included in this brochure are available through the Siemens sales organization worldwide. Availability and packaging may vary by country and is subject to change without prior notice. Some/All of the features and products described herein may not be available in the United States.

The information in this document contains general technical descriptions of specifications and options as well as standard and optional features which do not always have to be present in individual cases.

Siemens reserves the right to modify the design, packaging, specifications and options described herein without prior notice. Please contact your local Siemens sales representative for the most current information.

Note: Any technical data contained in this document may vary within defined tolerances. Original images always lose a certain amount of detail when reproduced.

Not for distribution in the US.

www.siemens.com/healthcare-magazine

Global Business Unit

Siemens AGMedical SolutionsComputed TomographySiemensstraße 191301 ForchheimGermanyPhone: +49 9191 18 - 0www.siemens.com/healthcare

Local Contact Information

Asia/Pacific:Siemens Medical SolutionsAsia Pacific HeadquartersThe Siemens Center60 MacPherson RoadSingapore 348615Phone: +65 9622 - 2026www.siemens.com/healthcare

Canada:Siemens Canada LimitedMedical Solutions2185 Derry Road WestMississauga ON L5N 7A6CanadaPhone: +1 905 819 - 5800www.siemens.com/healthcare

Europe/Africa/Middle East:Siemens AGMedical SolutionsHenkestraße 127D-91052 ErlangenGermanyPhone: +49 9131 84 - 0www.siemens.com/healthcare

Latin America:Siemens S.A.Medical SolutionsAvenida de Pte. Julio A. Roca No 516, Piso 7C1067ABN Buenos Aires ArgentinaPhone: +54 11 4340 - 8400www.siemens.com/healthcare

USA:Siemens Medical Solutions U.S.A., Inc.51 Valley Stream ParkwayMalvern, PA 19355-1406USAPhone: +1-888-826 - 9702www.siemens.com/healthcare

Global SiemensHealthcare Headquarters

Siemens AGHealthcare SectorHenkestraße 12791052 ErlangenGermanyPhone: +49 9131 84 - 0www.siemens.com/healthcare

Global Siemens Headquarters

Siemens AGWittelsbacherplatz 280333 MuenchenGermany

Order No. A91CT-41011-14M1-7600 | Printed in Germany | CC CT 41011 ZS 0510/27. | © 05.2010, Siemens AG

Cover Story The Best of Both Worlds in Neuro ImagingPage 6

News Best Balance Between Image Quality and Reduced DosePage 18

Business More for Less in MonacoPage 28

Clinical ResultsSOMATOM Defi nition AS+: CT Perfusion With Extended Coverage for Acute Ischemic StrokePage 50

Science CT in Pediatrics: Easier and Safer With the FlashPage 62


Documents

Somatom sessions 26