S2 Ultrasound in Medicine and Biology Volume 35, Number 8S, 2009

tracted from the refill time-intensity curve. On the other hand, func-tional studies with microbubbles suffer from a number of disadvan-tages. Fundamental to most functional studies, particularly those thatmeasure the amount rather than the timing of the enhancement, is thatthere is a predictable (ideally linear) relationship between the micro-bubble concentration and the signal strength they return. At least arelative correspondence has been demonstrated when using spectralDoppler with Levovist but non-linear modes with perfluoro micro-bubbles such as SonoVue have not been systematically investigated asyet. An additional problem is the microbubble’s decay, both spontane-ous (as the gas diffuses out and dissolves in blood) and resulting fromultrasound-induced destruction. The insonating power is not uniformlydistributed through the volume under study, making for inhomogene-ities in the received signal strength, and tissue movement may causeerrors as the region being studied changes, for example, with breathing,though tracking algorithms can adjust for this, at least within the scanplane. Use of the raw RF data rather than the log compressed video datagives more useful results and the ability to store raw data is availableon newer systems. Clinical functional studies include transit timing ofthe flow across the kidney and the liver: the latter was originallyimplemented using spectral Doppler to measure the time taken frominjection until appearance in the hepatic veins and was shown to becapable of distinguishing between grades of diffuse liver disease,especially cirrhosis. It also promises to be useful in staging livermetastases, which alter the liver’s blood, supply in a similar way tocirrhosis. Subsequently, a 2D version was developed that made use ofthe non-linear modes that were under development. For this muchsimpler method, a hepatic vein is targeted and kept in the field of viewbefore the injection is given. The arrival in the hepatic artery is readilyobserved anywhere in the liver, and the delay from this moment untilthe appearance of contrast in the hepatic vein is noted. Though muchsimpler to perform, the discrimination between the different degrees ofchronic hepatitis and cirrhosis is less complete. Functional studies oftumours treated with antiangiogenesis agents show great promise indemonstrating early response and predicting when treatment should bechanged. The quantification of the amount of enhancement seems to bethe most sensitive feature and is much more sensitive if RF data is used.Any of the components of time intensity curves can be turned intofunctional images by allocating a colour to the feature and presentingit as an overlay on the B-mode image. They have the potential to depictspatial variations of the original numbers

0006

Fetal Cardiac Functions in Diabetic PregnancyJon Hyett, Royal Prince Alfred Hospital, Australia

Diabetes is becoming more prevalent, affecting up to 9% of pregnantwomen in Australia. Women who have diabetes before pregnancy havean increased risk of structural heart defects and require careful reviewat the time of the 20 week anomaly scan. A preliminary assessmentmay be performed at 12 weeks gestation, at the time of NT assessment.More recently, an association between cardiac hypertrophy and mater-nal diabetes has been recognised - and has been reported to affect up to30% of these infants.Fetal myocardial hypertrophy is characterized by increased interven-tricular septal, left and right ventricular wall thickness at the end ofdiastole. As hypertrophy becomes more severe, ventricular stiffnessincreases, affecting diastolic ventricular filling as well as systoliccardiac function. These features can be assessed using ‘M’ mode andDoppler ultrasound.In this study we aim to ascertain whether these indices of cardiacfunction can be readily measured in the third trimester of pregnancy

during a routine growth and wellbeing scan and to determine whether

changes seen in the fetal period correlate with neonatal cardiac perfor-mance.

0007

3D/4D Ultrasound: Fetal EchocardiographyGreggory R DeVore, United States

This presentation will focus on the use of 3D/4D ultrasound to evaluatethe fetal heart. The content includes the following topics: (1) review ofthe differences between 3D and 4D STIC, (2) evaluation of the outflowtracts using the “spin” technique, (3) use of the invert mode, (4)discussion of “b-flow” technology, (5) discussion of tomographic ul-trasound imaging, and (6) presentation of cardiac anomalies using theabove technologies.

0008

The Clinical Outcome of Fetus with Prenataly DiagnosedEbstein’s AnomalyPeter Ching-Chang Hsieh, President, Taiwan Society of Ultrasoundin Medicine, Taiwan

Objective: Ebstein’s anomaly is a rare congenital heart defect charac-terized by tricuspid valvular dysplasia with downward displacement ofthe valve. The clinical spectrum may be asymptomatic into adult life orearly presentation in the fetal or neonatal period. We try to find outsome sonographic markers to predict its outcome.Material and Methods: Seventeen cases diagnosed in utero withEbstein’s anomaly from January 1996 to December 2008 were enrolledin this study. The final diagnoses were established by surgical findings,autopsy or postnatal image study. The antenatal sonographic features,gestational weeks being diagnosed, perinatal mortality, postnatal echo-cardiography, and long term outcomes were reviewed.Results: Antenatal sonographic findings included disproportion of our-chamber view, tricuspid regurgitation, enlargement of right atrium,cardiomegaly, pericardial effusion, and hydrops fetalis as well asassociated cardiac anomalies and extracardiac anomalies. There werethree cases of intrauterine fetal death and two cases of neonatal deathwhile three cases with termination of pregnancy. Five cases did notundergo postnatal surgery, but survival well. Poor outcome of thebabies came from those fetuses diagnosed with hydrops fetalis or/andfetal arrhythmia. Termination of pregnancy happened in those fetusesassociated cardiac or extracardiac anomalies.Conclusion: Ebstein’s anomaly can be diagnosed by antenatal ultra-sound, and the neonatal outcome is variable. Early detection is notassociated with poor neonatal outcome. Progression of cardiomegalywith hydrops fetalis was an ominous sign.

0009

Ultrasound of Entrapment Neuropathies of the Lower ExtremityCarlo Martinoli, University of Genova, Italy

Ultrasound (US) can give direct demonstration of a wide range ofneuropathies of the lower extremity. In the hip, the entrapment of thesciatic, femoral and lateral femorocutaneous nerves can be depictedwith US. Main signs of nerve compression include echotextural abnor-malities, displacement of the affected nerve from its normal course byspace-occupying masses and selective changes in the innervated mus-cles related to denervation edema and fatty infiltration. At the lateralknee, the entrapment of the common peroneal nerve typically occursbetween the bone and the fascia as the nerve winds around the fibularneck. In most cases, nerve traumas result from external pressure at thefibular neck. Ganglion cysts are one of the leading causes of peronealnerve compression at this site: these cysts may be divided in extran-

eural ganglia, which develop outside the nerve and compress it later