Abstracts S39

20 mmHg 1day after BV, meanwhile, about 93.4% children whosepressure gradient across the pulmonary valve less than 20 mmHg1month after BV.Conclusion: BV was a safe and effective technique for treating differ-ent aged children with pulmonary valve stenosis. It was feasible tofollow up with TTE.

0304

Value of Contrast Enhanced Ultrasound for ProtocolingRadiofrequency Ablation of Hepatocellular CarcinomaMin-Hua Chen, Peking University, China

Objective: The purpose of this study was to evaluate the use ofcontrast-enhanced ultrasonography (CEUS) in selecting patients withhepatocellular carcinoma (HCC) for radio frequency ablation (RFA).Methods: One hundred seventy-nine patients with HCC were dividedinto 2 groups before receiving RFA: a CEUS group and a controlgroup. The patients were concatenated and alternately apportioned intothese 2 groups. In the CEUS group, 92 patients underwent pre-RFACEUS using the contrast agent sulfur hexafluoride and enhanced com-puted tomography or magnetic resonance imaging before RFA forselecting suitable cases for RFA, and in the control group, conventionalultrasonography and enhanced computed tomography or magnetic res-onance imaging were performed in 87 patients for selecting patients.Results: In the CEUS group, 9 patients (9.8%) were excluded for RFAtherapy by CEUS. The other 83 patients (90.2%), with a total of 114lesions, were treated by RFA. In the control group, 5 patients (5.7%)were excluded for RFA. The other 82 patients (94.3%), with a total of107 lesions, were treated by RFA. During the follow-up period of 18 to50 months, the primary technique effectiveness rates in the CEUS andcontrol groups were 94.7% and 87.9%, respectively (P�0.1182). Thelocal tumor progression rate, the new HCC rate, and the repeated RFArate of the CEUS group were significantly lower than those of thecontrol group (P � .033, .004, and .001, respectively).Conclusions: Pre-RFA CEUS provides important information for se-lecting suitable patients for RFA. The use of CEUS in selecting patientswith HCC can decrease post-RFA local tumor progression and improvethe efficacy of RFA therapy.

0306

Evaluation of Ablation Efficacy of Liver Tumours UsingContrast Enhanced Ultrasound Including 3DFuminori Moriyasu, Tokyo Medical University, Japan

High intensity focused ultrasound (HIFU) has been used for treatmentof various kinds of cancer. Extracorporeal HIFU has been used for liverand pancreas cancers, although there are several limitations for treat-ment. One of the limitations is the complication of skin burns. Anotherone is attenuation of the HIFU power by the subcutaneous tissue andribs. Yet another is that the HIFU ablation area is so small that it takesa long time to ablate a tumor, for example, the approximate timerequired for ablation of a tumor of 5 cm in size might be several hours.Therefore, an enhancer is necessary to increase the ablation size anddecrease the required power for the desired HIFU ablation effect.Microbubble ultrasound contrast agents are known to enhance HIFUeffects. The enhancement effects of microbubbles are divided into twocategories; cavitation and non-cavitation effects. The cavitation effectis divided into thermal and non-thermal effects. Commercially avail-able ultrasound contrast agents act as cavitation nuclei resulting innon-thermal effects of cavitation when the microbubble is present inthe tissue exposed to HIFU energy.The size of hyper-echoic changes after HIFU treatment in the liver

followed by intravenous administration of microbubbles is increased 5

times more than without microbubbles. The threshold of HIFU powerfor echogenic changes, and cavitation induced area, can be loweredusing pre-administration of microbubbles.Sonazoid microbubbles accumulate in the liver after intravenous ad-ministration because they are phagocytosed by Kupffer cells. Thestable accumulation lasts long enough for them to be useful to enhanceHIFU therapy in the liver.It is expected that HIFU treatment will become safer and more widelyindicated using microbubble contrast agents.

0307

Genetic Ultrasound. 98% Detection Rate for Trisomy 21Greggory R DeVore, United States

This presentation will discuss the role of fetal echocardiography todetect fetuses with Down syndrome. Most studies have suggested that2nd trimester genetic ultrasound only detects between 50% and 70% offetuses with trisomy 21. The data presented in this paper will focus onthe role of fetal echocardiography to increase the detection rate forDown syndrome to 98%. The study that will be presented highlights thefact that over 30% of second trimester fetuses with Down syndromeonly had cardiac abnormalities! The role of Genetic Ultrasound willalso be discussed as it relates to 1st trimester NT screening.

0308

Prognostic Ultrasound for Congenital Diaphragmatic HerniaAlan Cameron, Queen Mother’s Maternity Hospital, United Kingdom

Epidemiology0.08 - 0.45 per 1000 births in world literature(1 per 2688 live births)AetiologyMajority are sporadic - only 2% occurring with familial asociationRare associations with teratogens80% left sided and majority isolated20% Can occur as part of a syndrome.Antenatal Diagnosis 2D ultrasoundAbnormal thoracic views in transverse plainStomach seen at same level of 4CVMediastinal shiftOther abdominal contents present in chest - bowel and ?liverColour Doppler can show portal and hepatic veins above diaphragmPolyhydramniosCDH- Ultrasound Prognostic CriteriaFirst goal of a lung assessment method is to predict viability andrequires to be performed � 26 weeksDetermination of “liver up” using 2D/ColourEstimation of the residual right lung volume using the lung:head ratio(LHR)3D Power Doppler of pulmonary vasculature- measures vascular resis-tance and thus functionLung to head Ratio (LHR)Two dimensional measurement of the contralateral lung by ultrasoundat the transaxial level of the 4 chamber view in diastole.Multiply these dimensions and divide by HCObserved/Expected ratios can predict severityReferencesDeprest et al Progress in intrauterine assessment of the fetal lung andprediction of neonatal function UOG 2005;25:108-111.Metkus et al Sonographic predictors of survival in fetal diaphragmatic

hernia. J Ped Surg 1996 31;48-52.