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Abstracts not widely employed in clinical practice. The disease patterns for chest lesions in children and infants are quite different from those in adults. Therefore, the application of chest sonography in pediatric patients also differs considerably from adult patients. From these viewpoints, we can expect a very exciting field to explore. Pediatric chest sonography is particularly useful in children with lower respiratory tract infections. In bronchiolitis, sonographic air-bronchogram is typical. In lobar pneumonia, sonographic features of consolidation/hepatization also are quite characteristic sonographic fluid bronchogram is a useful size to delineate secretion-filled bronchus in the lungs. Sonography is also a very sensitive and useful tool for detection of pleural effusion. Differentiation of transudatic pleural effusion from exudatic purulent empyema is not difficult with chest sonography. The former always show clear space between the two layers of pleura while the latter usually showed “dirty” irregular granular particles within clear space. In pleural fusion with nonpurulent exudates, floating filaments of different size often could be seen. Other lesions, such as lung abscess, congenital diaphragmatic hernia and mediastinal tumors could also be demonstrated on chest sonography. Additionally, the real-time nature of the chest sonography also provides a useful tool for dynamic study of the chest lesions. In view of the obvious positive information given by the chest sonography, we consider, for pediatric patients, chest sonography at least decreases the need for repeated chest X-rays. Although at the present time there is no evidence that pediatric chest sonography can totally replace conventional chest X-rays, the noninvasive, nonradiation and highly portable nature will further extend its future application in pediatric patients.

BREAST INTERVENTION 1242 Interventional breast sonography: From biopsy to ablation Fornage BD, M. D. Anderson Cancer Center, United States of America Because it is currently the only real-time cross-sectional imaging modality, sonography has emerged as the optimal guidance technique for percutaneous interventional procedures involving nonpalpable masses in the breast and the regional nodal basins. The various techniques of needle biopsy, ranging from fine-needle aspiration biopsy to the use of vacuum-assisted large core biopsy devices, will be briefly compared. Techniques available for pre- and intraoperative localization of nonpalpable masses will be mentioned. The emphasis will be placed on the description of new ultrasound-guided techniques of percutaneous ablation, including radiofrequency ablation and cryoablation of benign and malignant breast tumors.

FOCAL LIVER DISEASE 1243 Hepatocellular carcinoma: From the angiogenetic factors to the imaging evidence Rapaccini GL, Pompili M, Pola R, Catholic University, Italy Hepatocellular carcinoma (HCC) is a frequent complication of liver cirrhosis, particularly virus-related. The tumor arises in cirrhotic liver emerging from preneoplastic lesions, the dysplastic nodules (Rapaccini GL et al, Dig Dis Sci, 1990). The neoangiogenesis proceeds progressively to the development of the tumor: it is the main pathologic process of this kind of carcinogenesis (Imura S et al, J Med Invest,

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2004). Several angiogenic growth factors, such as VEGF 121, VEGF 165, VEGF 189, Angiopoietin-1 and -2, are implicated in some cardiovascular diseases (Pola R et al, Nature Medicine, 2005), inflammatory diseases and tumors (small-cell lung cancer, gastrointestinal carcinomas, pancreas adenocarcinoma). Furthermore, the correlation between the expression of angiogenin (ANG) and the microvessel density in HCC (Hisai H et al, Clin Cancer Res, 2003) has been demonstrated. The imaging techniques able to study the vascularization of a hepatic nodule are obviously an excellent method to diagnose HCC: contrastenhanced ultrasonography (CEUS) can differentiate the preneoplastic nodules also from the well-differentiated HCC. The dimensions of the lesions do not affect the diagnostic accuracy of the technique. CEUS is an accurate methodology to assess the efficacy of ablation treatments (PEI, radiofrequency, laser) of hepatocellular carcinoma nodules and metastatic lesions to the liver (Pompili M et al, Liver Int, 2005). It is hypothetical that in the future a population at risk of development of HCC (i.e., cirrhotic patients) may be followed-up by the assay of circulating factors of angiogenesis: an elevation of this kind of marker will indicate the patients to study by the “angiographic” imaging techniques.

LESION DETECTION USING US CONTRAST AGENT 1244 Contrast imaging in every day practice Fabrizio Calliada, Carlo Filice, Guido Torzilli, University of Pavia, Italy; Institute of Infectious Diseases, Italy; Third Department of Surgery, Faculty of Medicine, University of Milan, Istituto Clinico Humanitas, Irccs, Rozzano (Milano), Italy Contrast agents are part of the every day sonographic practice in Italy and Europe. The reason for this wide acceptance resides in two major causes: the availability of new generation contrast agents capable to be insonated at low US power without destruction, thus permitting a real time examination of target organs for a sufficient period of time, avoiding any change in the normal sonographic behavior. New contrast specific software designed to visualize the presence of contrast at very low power engendering two simultaneous goals: preserve the bubble life in the blood circulation and cancel the signal deriving from stationary tissues. After more than five y of activity with CEUS, the possible applications in every day practice are numerous, interesting and sometime really amazing. Liver examination for solid lesion detection, characterization intervention are the more obvious, experienced and long lasting CEUS applications and also the applications where contrast agents have changed radically our way to manage an ultrasound examination. But CEUS introduction has changed also the US position and concept in the flow chart of liver lesion imaging favorably comparing with CT and MRI. EFSUMB guidelines for CEUS liver examination are the consequence of the widespread European acceptance and experience about CEUS. Contrast enhanced intraoperative US is a new liver application, recently introduced, with interesting potential improvement over baseline IOUS, permitting to recognize and characterize lesions not visible even at intraoperative probes. Liver is, for sure, the application where we have the greatest experience, but it is not the only one! Kidney is a promising field of research for therapy guiding/follow up and also for parenchymal perfusion studies after embolic accidents. Small parts applications are the new frontier and even if they are only a work in progress, the first results concerning lymph nodes and breast tumors seem to be a promising field of research with potential clinical impact.