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CEwebsource.com is produced by Enterprises for Continuing Education Inc. (ECEI), 10381 Citation, Ste. 200, Brighton, MI 48116, (810) 229-3354. The views expressed in the journal are the authors’ and do not necessarily represent those of ECEI. Full and complete pre- scribing information should be reviewed regarding any product mentioned herein prior to use. ECEI hereby authorizes you to copy docu- ments published by ECEI on the World Wide Web for non-commercial use only. In consideration of this authorization, you agree that any copy of these documents which you make shall retain all copyright and other proprietary notices contained herein. BASIC ABDOMINAL SONOGRAPHY: A PROCEDURAL OVERVIEW John Fatchett II, RDMS, Ultrasound Practitioner University of Michigan Medical Center Department of Radiology, Ultrasound Division INTRODUCTION The purpose of this paper is to outline basic grayscale sonographic evaluation of abdominal anatomy in the average patient. This paper reviews patient preparation relative to clinical questions, introductory instrumenta- tion and scanning techniques, transducer selection, and the anatomy to be evaluated. PATIENT PREPARATION A six- to eight-hour minimum fast prior to the exami- nation is fairly standard patient preparation for abdom- inal ultrasound in labs. 1 This preparation is for any exam, or combination of exams, evaluating the liver, gallbladder, bile ducts, pancreas, and abdominal aorta. Examinations evaluating only the kidneys and/or spleen do not require fasting. Fasting helps to minimize gastrointestinal air, pre- vent a change in the hepatic vasculature or biliary tree, and eliminate normal physiologic gallbladder contraction (Figures 1A–1C). 1,2 Any air in the ultrasound beam path is a limiting factor because the beam cannot penetrate the air due to the acoustic impedance mismatch between air and biological tissue (Figure 2). 3-5 Gallbladder contrac- tion, engorgement of hepatic vasculature, and changes in the biliary tree due to eating can be false-positive indica- tors of pathologic conditions such as cholecystitis, portal hypertension, and biliary obstruction. FIGURE 1. Figures 1A and 1B represent a con- tracted gallbladder in a postprandial patient. Note the thickened, collapsed wall (arrow), which results in poor visualization of the lumen. Figure 1C de- picts a well-distended gallbladder in the adequately prepped patient, NPO for 6-8 hours, allowing ad- equate evaluation of the lumen, wall, and perichole- cystic space. 1A 1B 1C

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CEwebsource.com is produced by Enterprises for Continuing Education Inc. (ECEI), 10381 Citation, Ste. 200, Brighton, MI 48116, (810) 229-3354. The views expressed in the journal are the authors’ and do not necessarily represent those of ECEI. Full and complete pre-scribing information should be reviewed regarding any product mentioned herein prior to use. ECEI hereby authorizes you to copy docu-ments published by ECEI on the World Wide Web for non-commercial use only. In consideration of this authorization, you agree that any

copy of these documents which you make shall retain all copyright and other proprietary notices contained herein.

BASIC ABDOMINAL SONOGRAPHY: A PROCEDURAL OVERVIEWJohn Fatchett II, RDMS, Ultrasound PractitionerUniversity of Michigan Medical Center Department of Radiology, Ultrasound Division

INTRODUCTIONThe purpose of this paper is to outline basic grayscale

sonographic evaluation of abdominal anatomy in the average patient. This paper reviews patient preparation relative to clinical questions, introductory instrumenta-tion and scanning techniques, transducer selection, and the anatomy to be evaluated.

PATIENT PREPARATIONA six- to eight-hour minimum fast prior to the exami-

nation is fairly standard patient preparation for abdom-inal ultrasound in labs.1 This preparation is for any exam, or combination of exams, evaluating the liver, gallbladder, bile ducts, pancreas, and abdominal aorta. Examinations evaluating only the kidneys and/or spleen do not require fasting.

Fasting helps to minimize gastrointestinal air, pre-vent a change in the hepatic vasculature or biliary tree, and eliminate normal physiologic gallbladder contraction (Figures 1A–1C).1,2 Any air in the ultrasound beam path is a limiting factor because the beam cannot penetrate the air due to the acoustic impedance mismatch between air and biological tissue (Figure 2).3-5 Gallbladder contrac-tion, engorgement of hepatic vasculature, and changes in the biliary tree due to eating can be false-positive indica-tors of pathologic conditions such as cholecystitis, portal hypertension, and biliary obstruction.

FIGURE 1. Figures 1A and 1B represent a con-tracted gallbladder in a postprandial patient. Note the thickened, collapsed wall (arrow), which results in poor visualization of the lumen. Figure 1C de-picts a well-distended gallbladder in the adequately prepped patient, NPO for 6-8 hours, allowing ad-equate evaluation of the lumen, wall, and perichole-cystic space.

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FIGURE 2. In this patient, the gastric body and antrum are distended with air, obscuring and pre-venting visualization of the pancreas and abdom-inal aorta. The arrows indicate the leading edge of the gastric wall.

INTRODUCTORY INSTRUMENTATION AND SCANNING TECHNIQUES

Although this paper deals chief ly with anatomy, an abbreviated discussion of machine technique is neces-sary. The basic utilization of depth, gain, focal zone, and dynamic range are vital in taking a diagnostic image. The depth of the image should be set in such a manner that the target anatomy takes up the majority of the field of view. For example, when evaluating the liver, you should be able to see echoes from a few centimeters deeper than the liver margin. This ensures that you are fully visual-izing the target structure and also able to evaluate the immediate vicinity. Setting the depth too far past the organ of interest decreases the visual resolution of that organ in that the image size on the display monitor does not change as you add information (the deeper you image, the more anatomy is displayed in the same amount of space), effectively shrinking the target anatomy into the near field of the displayed image to include the added deeper information (Figure 3A).

The ultrasound beam has a natural focal zone, but the machine allows you to electronically focus the beam at a selected depth. The electronic focal zone should be placed at or slightly below the target anatomy. Many of the newer systems have faster and more intricate pro-cessing to allow multiple focal zones for general abdom-inal imaging. Previous systems were too slow, and, typically, sonographers would use only multiple focal zones when imaging small parts structures that were not moving. Depending on the imaging system, you may be able to utilize multiple focal zones without a noticeable decrease in frame rate.

Overall gain and time gain compensation (TGC) curve settings are also crucial (Figure 3B). Improper gain set-tings can mask or mimic pathology. For instance, over-

gaining can add echoes to cystic structures and make them appear complex or solid. As another example, over-gaining the liver technique results in an appearance com-parable to a fatty liver. Under-gaining can significantly decrease the sensitivity, remove echoes from a complex structure, and give a simple appearance or lose soft-tissue information. Using the dynamic range controls helps when changing the gain control is deleting infor-mation or adding noise. The ultrasound machine pro-cesses the returning echo and assigns it a level of gray, somewhere between black and white, correlating to that signal's amplitude, or strength. The number of levels of gray you can display is the dynamic range. Increasing or decreasing the dynamic range, or levels of gray, simply reassigns the echoes rather than omitting them or ampli-fying noise, which is effectively what happens when you increase or decrease the gain control. The gain settings should be used to set the image sensitivity; the dynamic range is for tailoring the image and aiding the diagnostic capability of the information (Figure 3C).

TRANSDUCER SELECTIONProper transducer selection for the examination requires

consideration of the body habitus of the patient being evaluated and the exam to be performed. An increase in the frequency of a transducer correlates to an increase in resolution, or increased sensitivity to smaller struc-tures.3-5 What is gained in resolution, however, is lost in depth of penetration because the higher frequencies are absorbed or attenuated by the tissues more rapidly, resulting in a loss of signal received.1,4,5 A decrease in the transducer frequency gives up some sensitivity, but gains a greater depth of penetration.3-5 For the average adult patient, a 3.5 megahertz (MHz) transducer of a sector or curved array design is a good place to start. Linear transducers, by design, are better for superficial imaging and are not necessarily best where a large field of view is essential, whereas sector and curved array designs, with a larger field of view, are better for imaging deeper and more expansive structures.3-5 A larger or more dif-ficult-to-image patient may require a 2.5 MHz, and a smaller patient may require a 5 MHz, or even a 7 MHz (usually in pediatric cases).

More than one transducer may also be used. For instance, a 3.5 MHz for the liver, and if the gallbladder is more anteriorly located, a 5 MHz (or possibly even a linear transducer) for this area may provide more detailed images. The introduction of multiple frequency or wide-band transducers, in some cases, has decreased the need for switching probes. You will attain improved depth penetration along with increased near-field resolution when using a transducer that uses frequencies ranging from 3 MHz to 5 MHz, or from 4 MHz to 7 MHz, rather than a dedicated single-frequency probe. Also, many manufacturers have implemented a pushbutton feature allowing a change of the operating frequency of

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the probe without physically switching scan heads. This feature gives greater f lexibility to the examiner, with decreased exam time and effort, however minimal that may be.

FIGURE 3. Figure 3A shows improper depth set-ting and focal zone placement, along with increased gain setting, all together decreasing the image quality and diagnostic capability. Figure 3B shows improved depth setting, but continued improper focal zone placement and incorrect TGC setting, again resutling in poor image quality. Figure 3C shows correct depth setting, addition of a second focal zone with correct focal zone placement, and proper gain setting, demon-strating an appropriate diagnostic image.

THE ANATOMY TO BE EVALUATEDThe anatomy to be evaluated depends largely on the

clinical question to be answered. A detailed patient history to make the investigators aware of previous or existing medical problems, relevant surgeries, abnormal lab values, and previous imaging studies are necessary, along with patient communication. Rather than merely settling for the instruction "Rule out abdominal pain" on the requisition, asking a question such as "What con-cerns bring you here (or to your referring physician)," or the even more basic "Where/how/when does it hurt," can bring out more specific questions or target areas.

The option for targeted anatomic evaluation vs complete upper abdominal imaging will depend upon the imaging request and the ultrasound lab protocols. The guidelines followed in one lab, at the University of Michigan, typi-cally require complete evaluation of the visceral organs in the upper abdomen, unless a complete evaluation was per-formed within the last six months, and a targeted follow-up is requested. For example, a complete abdominal exam was performed five or six months ago. The patient was found to have a liver cyst, and follow-up examination has been requested to observe for changes in the size and/or composition of the cyst. In this setting, a targeted eval-uation of the liver and cyst is appropriate. If there are additional factors such as elevated liver function tests, however, complete hepatic and biliary system imaging is warranted, including the hepatic ducts, gallbladder, and pancreas. A history of general abdominal discomfort or f lank pain would require the kidneys and spleen to be added to the picture. Often, you will interrogate each of the organs for a complete abdominal examination.

Place the transducer in the midline epigastric region in a longitudinal plane to begin scanning the liver. Start with the lateral segment of the left lobe, and sweep to the medial segment and caudate lobe. Pay close attention to any change in the normal heterogeneous appearance of the liver parenchyma to evaluate for pathologic signs such as increased attenuation, irregular borders, masses, f luid collections, or dilated bile ducts along the portal veins (Figures 4A–4D).1 Landmarks to look for and document are the gastroesophageal junction (Figure 5), proximal abdominal aorta, celiac axis, and superior mes-enteric artery (Figure 6) posterior to the lateral segment of the left lobe.1,3,6

If you are also including the abdominal aorta in the scan protocol, continue inferiorly in a longitudinal plane and take anterior to posterior measurements of the lumen at the proximal, mid, and distal segments down to the level of the iliac bifurcation, approximately at the level of the umbilicus and repeat in a transverse plane, including transverse luminal measurements of the same areas. The anterior to posterior luminal diameter mea-surement may be performed in either the longitudinal or transverse scan planes; your department may have a predetermined preference (Figures 7A–7D). You may

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FIGURE 4. Figure 4A shows the right hepatic lobe, demonstrating normal, homogeneous echotexture. Figure 4B shows a comparable scan plane in a different patient, demonstrating hepatic parenchymal idsease. Note the in-creased attenuation and degraded image quality. Figure 4C shows normal right hepatic lobe at the porta hepatis, with a normal appearing main and right portal vein. Figure 4D shows a comparable scan plane in different pa-tient, again demonstrating hepatic parenchymal disease. Note the degraded image quality of the portal vessels and the inability to identify the surrounding collagenous capsule, as seen in the previous image.

FIGURE 5. Longitudinal view of the left hepatic lobe and the proximal abdominal aorta, demonstrating the gastroesophageal junction (single arrow) at the dia-phragm between the two. Note the collapsed gastric antrum (double arrow) bordering the inferior margin of the left lobe, cephalad to the pancreatic body.

FIGURE 6. Longitudinal view of the proximal ab-cominal aorta, demonstrating the first anterior branches, the celiac axis (single arrow) and the su-perior mesenteric artery (double arrow, immediately caudal to the celiac axis).

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FIGURE 7. Figure 7A depicts a longitudinal view of the mid-segment of the abdominal aorta. Figure 7B shows proper caliper placment for the anterior to posterior luminal diameter measurement. Figure 7C is a transverse view of the mid-segment of the abdominal aorta. Figure 7D depicts proper caliper placement for the transverse luminal diameter measurement, along with the optional method for performing the anterior to posterior luminal diameter measurement.

FIGURE 8. Figure 8A is a longitudinal view of the ligamentum teres (arrow), the linear echogenic structure ex-tending from the inferior aspect of the left portal vein. Figure 8B is a transverse view of the ligamentum teres (arrow).

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FIGURE 9. Figure 9A is a longitudinal view of the ligamentum venosum (arrow), separating the left lobe from the caudate lobe posteriorly. The inferior vena cava is noted posterior to the caudate lobe. Figure 9B is a transverse view of the left hepatic lobe, with the ligamentum venosum (arrow) visualized at the anterior aspect of the caudate lobe.

FIGURE 10. Figure 10A is a transverse view of the hepatic veins coursing into the inferior vena cava (IVC). Figure 10B is a transverse view of the main (MPV) and right (RPV) portal vines coursing into the right hepatic lobe. Note the echogenic collagenous capsule (arrow) surrounding the portal vein in contrast to the hepatic veins.

need to apply downward pressure with the transducer to push some of the bowel gas out of the scan window, because the mid and distal segments are completely cov-ered by bowel.3 Placing the patient in a right lateral decubitus position and using the spleen as an acoustic window can, at times, aid in visualization of the mid and possibly the proximal segments.

Continuing with the left lobe anatomy and landmarks, scan and document the ligamentum teres/umbilical vein remnant (Figures 8A and 8B), which is the division between the lateral and medial segments of the left lobe, the ligamentum venosum between the posterior left lobe and the caudate lobe (Figures 9A and 9B), and the left hepatic and portal veins.1,3,6 To distinguish between the portal vein and hepatic vein, remember that the hepatic veins are located more superiorly and have poorly defined

borders, becoming larger as they empty into the inferior vena cava, whereas portal veins branch away from the porta hepatis in the right lobe and have echogenic collag-enous walls (Figures 10A and 10B).3 The inferior vena cava is visualized posterior to the left medial and caudate lobes (Figures 9A and 9B). This portion may be evalu-ated for narrowing or intraluminal mass such as tumor or thrombus. To finish the longitudinal images of the liver, change to an intercostal and right lateral approach to eval-uate the right lobe. In some patients, usually pediatric, the right lobe can be evaluated from the midline approach, but this is more the exception than the rule. Here, again, sweep from medial to lateral. The middle hepatic vein divides the right from the left lobe superiorly, and, infe-riorly, the main lobar fissure is another dividing mark, which can be seen as an echogenic line running from

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FIGURE 11. Longitudinal image of the right hepatic lobe, demonstrating the main lobar fissure (arrow). It is the linear echogenic structure running from the portal vein to the gallbladder neck, where it then opens into the gallbladder fossa and gallbladder (GB).

FIGURE 12. The porta hepatis in the right hepatic lobe, demonstrating the main and right portal veins posterior to the common hepatic duct (couble arrow), and the proper hepatic artery (single arrow).

FIGURE 13. Longitudinal view of the gallbladder (GB) in the gallbladder fossa at the inferior aspect of the main lobar fissure (arrow).

FIGURE 14. Figure 14A shows a longitudinal scan plane demonstrating the common hepatic duct in long asis, draping over the main portal vein (MPV) and hepatic artery (arrow), seen in their transverse planes. Figure 14B shos proper caliper placement for the intrahepatic ductal measurement.

the right portal vein to the gallbladder (Figure 11).1,3 Continuing to the inferior margin, the porta hepatis is where the main portal vein, proper hepatic artery, and common bile duct are located (Figure 12). Lateral to that are the common hepatic duct (common duct); the right, right posterior, and right anterior branches of the portal vein; and, at the lateral margin, is the right hepatic vein.1,3,6 Return to the midline approach in a transverse scan plane and sweep from the diaphragm through the inferior margin of the left and caudate lobes, doing the same for the right lobe from the intercostal or right lat-eral approach. Because most of the liver is inside the rib cage, imaging can sometimes present a challenge in get-ting around or through the ribs. A left lateral decubitus position, deep inspiration, or even full expiration while distending the belly can possibly move the liver into a more approachable position.3

The gallbladder lies positioned against the inferior liver edge, posteriorly, within the gallbladder fossa, which is located in the inferior portion of the main lobar fissure (Figure 13).1,3,6 Longitudinal and transverse images can

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be obtained either from an intercostal or subcostal window to look for stones, polyps, sludge, folds, wall thickening, air, or pericholecystic f luid. Deep inspiration can often move the gallbladder out from under the costal margin. The gallbladder is quite frequently anterior enough to be well seen with a higher frequency transducer, allowing for improved resolution.4,5

Left lateral decubitus images should also be obtained, regardless of whether there were any findings on the other images. In this decubitus position, when the gall-bladder falls into a different location, the imaging can potentially reveal findings not visible in a supine view.3 Using the upright position is often overlooked as another option for better gallbladder visualization or for confir-mation of pathologic findings, such as mobility of a stone lodged in the gallbladder neck or a stone vs polyp deter-mination. A measurement of the common hepatic duct is standard in evaluating the biliary tree. Measurement for the common hepatic duct is obtained where the duct drapes over the main portal vein and proper hepatic artery (Figure 14A).1 Here, the cystic duct joins the common hepatic duct to form the common bile duct, which exits the liver parenchyma medially. The measure-ment is taken at this location to assure an intrahepatic measurement (Figure 14B).1 Because the caliber of the extrahepatic portion has a larger allowance, if the mea-surement is taken extrahepatically and incorrectly labeled as the common hepatic duct, the reported number inac-curately reflects biliary dilatation (Figures 15A and 15B). A normal value for the common hepatic duct measure-ment should equate to about 1 mm per ten years of age: for example, 3 mm for a 30-year-old patient.3 The duct can measure larger in a postcholecystectomy patient.3 Extrahepatically, now called the common bile duct, it can be found anterior to the main portal vein coursing towards the inferior margin of the pancreatic head, where it forms a common trunk with the pancreatic duct at the ampulla of Vater in the duodenum.1

The pancreas lies transverse midline, the head resting directly anterior to the inferior vena cava, the body directly anterior to the conf luence of the splenic and portal veins (Figure 16). Deeper, you can see the superior mesenteric artery and aorta in their transverse axis, and finally the tail between the spleen and upper pole of the left kidney.1,3,6

The pancreatic duct, also seen running in a trans-verse plane from tail to head, should measure approxi-mately 2 mm or less.3 The gastric antrum and a portion of the duodenum lie anterior to the area encompassing the pancreas and extrahepatic bile duct and make the section difficult to image in most cases, because even after fasting the antrum and duodenum are typically gas filled, creating an acoustic shadow blocking all or most of the target anatomy (Figure 17A).3-5 Change of patient position, deep inspiration, or ingestion of water can be helpful in this situation (Figures 17B and 17C).3 When choosing to use ingestion of water to displace gastric

FIGURE 15. Figure 15A shows an incorrect scan plane and caliper placement for the common hepatic duct measurement, or the intrahepatic portion. This image is actually the common bile duct, or the extra-hepatic portion. Figure 15B shows the same patient, with corrected scan plane and caliper placement, which now demonstrates the appropriate image with correlating measurement.

FIGURE 16. Transverse scan plane depicting the pancreas in its long axis, posterior to the left hepatic lobe and gastric antrum, anterior to the splenic-portal vein confluence.

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FIGURE 17. Figure 17A depicts the gastric antrum (arrow), distended with air, obscuring vi-sualization of the pancreas. Figure 17B is an image of the same patient after ingestion of water. The liquid begins to displace some of the contents within the stomach (STO) and the pancreas, which is di-rectly posterior to it, becomes partially visible. The water within the stomach lumen (STO) continues to creaste an acoustic window, and a diagnostic image of the pancreas is obtained, utilizing the water path as seen in Figure 17C.

FIGURE 18. Figure 18A shows a longitudinal image of the spleen (arrow) in the left upper quad-rant. Figure 18B shows another view of the spleen, with the pancreatic tail (arrow) visualized between the spleen and the upper pole of the left kidney (LK).

air and act as an acoustic window, the use of a drinking straw is effective to reduce the amount of air swallowed with the water.

The spleen is in the left upper quadrant under the left hemidiaphragm and is bordered medially by the left lobe of the liver and the stomach and inferiorly by the pancre-atic tail and left kidney (Figures 18A and 18B).1,3 Place the patient in a right lateral decubitus position and scan in a longitudinal and transverse oblique plane between the ribs, evaluating splenic size and texture.

The kidneys are retroperitoneal and lie posteriorly on the lower portion of the quadratus lumborum muscle, roughly between the 12th thoracic and 3rd lumbar ver-tebral bodies—usually with the left kidney 1 cm to 2 cm higher than the right.1,3,6 They are bordered medi-ally by the psoas muscle and laterally by the transverse abdominus muscle.1,3,6 To evaluate renal length and parenchymal integrity and check for masses, calculi, and calyceal, pelvic, or ureteral dilatation in the right kidney, scan from an anterolateral or coronal position with the patient supine. Use the liver for a window as much as possible (Figure 19A). If bowel obscures the lower pole, roll the patient into a left lateral decubitus position or have the patient take a deep breath to move the liver,

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FIGURE 19. Figure 19A is a longitudinal image of the right kidney (arrow), using the right hepatic lobe as an acoustic window. A transverse view of the right kidney (arrow) in the same patient is shown in Figure 19B.

adrenal glands are not typically seen in the average adult patient, but knowing their approximate location is impor-tant because it may be necessary to differentiate upper pole renal from adrenal pathology.3 The right adrenal gland lies between the upper pole of the right kidney, the pos-terior surface of the liver, and the inferior vena cava.1,3,6 The left adrenal gland rests on the upper pole of the left kidney, bordered anteromedially by the spleen.1,3,6

CONCLUSIONThis brief guide has provided a basic understanding

on where and how to get started with general abdom-inal ultrasound imaging. Certainly, much more may be learned in regards to sonographic physics and instru-mentation, pathologic evaluation, and visceral vascular studies, all of which should build on the base of these general guidelines and techniques.

which may help displace the bowel or move the kidney into a better acoustic window.3 Typically, the same scan window and technique can be used for the transverse images (Figure 19B).

The left kidney is often more difficult to image because the spleen does not afford much of a scan window and the majority of the remaining left upper quadrant struc-tures are bowel (Figure 20A).1,3,6 Scanning coronally or more posteriorly, rolling the patient into a right lateral decubitus position with a deep suspended inspiration is often the only technique available to get around the bowel gas.3 Scanning from a posterior approach (often as a last resort) may provide diagnostic information, although the images may not be aesthetically pleasing. However, in some instances this approach can yield quality images, ending in a truly diagnostic study (Figure 20B).

Depending on the protocol set up by the lab, you may also need to include longitudinal and transverse images of the urinary bladder to complete the renal study. The

FIGURE 20. Figure 20A is a longitudinal, anterior intercostal view of the left kidney. The spleen (SPL) affords an acoustic window sufficient for viewing only the upper and mid portions of the kidney. The result is nonvisualization of the lower pole (LP) area from this scan plane. Figure 20B shows a coronal or more posterior approach in the same patient, and the left kidney, specifically the lower pole (arrow) is better visualized.

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REFERENCESRumack CM, Wilson SR, Charboneau JW, eds. Diagnostic Ultrasound Vol 1. 2nd ed. St. Louis, Mo: Mosby-Year Book; 1998.Tortora GJ. Principles of Anatomy and Physiology. 6th ed. New York, NY: Harper and Row; 1990:758-9.Sanders RC Miner NS, eds. Clinical Sonography: A Practical Guide. 2nd ed. Boston, Mass: Little, Brown and Co; 1991.Hykes DL. Ultrasound Physics and Instrumentation. 2nd ed. St. Louis, Mo: Mosby-Year Book; 1992.Bushong SC. Diagnostic Ultrasound: Physics, Biology, and Instrumentation. St. Louis, Mo: Mosby-Year Book; 1991.Mittelstaedt CA. Abdominal Ultrasound. New York, NY: Churchill Livingstone; 1987.

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BASIC ABDOMINAL SONOGRAPHY POST TESTExpires: June 15, 2011 Approved for 1 ARRT Category A Credit.

1. The patient preparation for abdominal ultrasound typically consists of fasting _______ hours prior to the exam

1–23–56–810–12

2. Examinations evaluating only the kidneys or spleen

require the patient take a laxative the day before.require the patient to fast for a certain number of hours.require the patient to have only clear f luids for 12 hours.do not require a fasting preparation.

3. Which of the following is a consequence of setting the depth too far past the organ of interest?

The visual resolution of the organ of interest is decreased.The frame rate is noticeably decreased.The target anatomy takes up the majority of the field of view and reveals echoes from just a few centimeters beyond the area of interest.Image distortion can mimic a condition such as cholecystitis or portal hypertension.

4. Which of the following is a possible consequence of setting the gain too high?

Echoes can be added to cystic structures, making them appear complex or solid.Echoes are removed from a complex structure, resulting in a simple appearance.Soft tissue information is lost.Streak artifact degrades the image.

5. Increasing the dynamic range effectively limits the returning echo.increases the number of shades of gray displayed.decreases the image sensitivity.increases the size of the image displayed.

6. Transducer selection is dependent on patient preparation.patient age and mobility.patient body habitus and the exam to be performed.the sonographer's preference.

7. What is the tradeoff for using a transducer with higher frequency?

Decreased sensitivity to smaller structuresDecreased resolutionMasked or mimicked pathologyLoss in depth of penetration

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8. By design, linear transducers are betterfor superficial imaging.when a large field of view is essential.for imaging deeper structures.when the patient is obese.

9. 7 MHz transducers are most commonly used fordeep structures.large patients.pediatric patients.average adult patients.

10. To begin scanning the liver, you should place the transducer

at the level of the umbilicus.toward the left, at the level of the iliac crest.approximately four inches to the right of the umbilicus.in the midline epigastric region.

11. The ligamentum teres and umbilical vein divide the lateral and medial segments of the left lobe of the liver.posterior left lobe and the caudate lobe of the liver.body and tail of the pancreas.right lobe of the liver into three segments.

12. Compared to the portal vein, hepatic veinsare located more inferiorly and have clearly defined borders.are located more superiorly and have poorly defined borders.branch away from the porta hepatic in the right lobe.have echogenic collagenous walls.

13. In most situations, the best way to evaluate the right lobe of the liver longitudinally is

a midline approach.an intercostal and right lateral approach.by placing the patient in a right lateral decu-bitus position and using the spleen as an acoustic window. by placing the patient in a prone position.

14. The gallbladder fossa is locatedin the back part of the longitudinal fissure and is situated mainly on the posterior surface of the liver.between the posterior surface of the liver and the diaphragm.in the inferior portion of the main lobar fissure.between the quadrate lobe and the left lobe of the liver.

15. In addition to images taken with the patient supine, left lateral decubitus images of the gall-bladder should be obtained because

the position of the gallbladder can change, potentially revealing findings not seen on the supine view.this is the only way that the common bile duct can be visualized.

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a.

b.

this procedure moves the gallbladder out from under the ribs. this is the only position that allows use of a higher frequency transducer.

16. Which of the following is considered a normal measurement for the common hepatic duct of a 50-year-old patient?

2 mm5 mm7 mm9 mm

17. Which is a normal measurement for the pancreatic duct?

2 mm2–3 mm3–4 mm6 mm

18. Which of the following techniques is NOT rec-ommended to better visualize the pancreas and extrahepatic bile duct?

Change the position of the patient.Have the patient take in a deep breath.Have the patient drink water through a straw.Have the patient drink a carbonated sugar-free beverage.

19. What position is best for evaluating the spleen?ProneSupineLeft lateral decubitusRight lateral decubitus

20. The kidneys are bordered medially by the transverse abdominus muscle.hepatic f lexure or the splenic f lexure of the colon.psoas muscle.teres major muscle.

c.

d.

a.b.c.d.

a.b.c.d.

a.b.c.d.

a.b.c.d.

a.b.

c.d.

Page 13: Abdominal Sonography

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