Noninvasive acoustic radiation force impulse (ARFI) elastography for assessing the severity of fibrosis in the post-operative patients with biliary atresia.

PURPOSE: Liver biopsy (LB) is still considered the "gold standard" for hepatological evaluation, but recently noninvasive methods have attempted to replace this invasive procedure. Recently, acoustic radiation force impulse (ARFI) imaging has been developed as a noninvasive modality to evaluate the stiffness of tissues. ARFI imaging theoretically measures liver stiffness of all the segments independently. The aim of this study was to determine whether ARFI elastography is a reliable method for predicting the severity of fibrosis in the post-operative patients with biliary atresia. METHODS: ARFI elastography was performed 21 times in eight patients with biliary atresia over the last 2 years. At the same time, we measured serum hyaluronic acid (H value), which is one of the serum elastic makers, to compare ARFI versus values in these patients. We obtained ARFI versus values as the median of S2 to S8 by three consecutive measurements acquired with a Siemens Acuson S2000 (Siemens Medical Systems, Germany). RESULTS: Histological evaluation of fibrosis is graded from F0 (normal) to F4. The normal H value is under 50 mg/dl. One patient had F0 (H value 29.2 mg/dl), four had F1 (H value 11.5-18.1 mg/dl), one had F3 (H value 61.3 mg/dl), two had F4 (H value 29.2, 112 mg/dl). One patient with F4 whose ARFI versus value (3.56 m/s) was the highest, needed liver transplantation and her liver was cirrhotic. CONCLUSION: These findings suggest that ARFI measurement may be a reliable method for predicting the severity of fibrosis after a Kasai operation.

Sonographic characterization of 271 hepatic hemangiomas with typical appearance on CT imaging.

PURPOSE: Hepatic hemangioma is the most frequent benign solid tumor that requires differentiation from hepatic malignancy on ultrasonography. Useful ultrasound findings are therefore required for diagnosis. SUBJECTS AND METHODS: The following factors were investigated for 271 masses diagnosed as hepatic hemangioma by contrast-enhanced computed tomography (CT) in 188 patients: hepatic subsegment location, shape, maximum diameter, internal echo level, hyperechoic rim, posterior echoes, marginal hypoechoic band (halo), lateral shadow, blood flow signal in the central portion of the mass, and underlying liver disease. RESULTS: Hepatic masses were classified by internal echo pattern as homogeneous hyperechoic (35.0%), homogeneous hypoechoic (22.9%), isoechoic (5.2%), mixed hyperechoic (22.1%), or mixed hypoechoic (14.8%) masses. Twelve masses were isoechoic, and could be recognized by the hyperechoic rim. Posterior echo enhancement was present in 66 masses. There were no cases of posterior echo attenuation. A halo was present in six masses, with the underlying condition being fatty infiltrated liver in two masses; a hypoechoic region with a small amount of fat deposit was present around the mass, and this resembled a halo. This finding was termed a "pseudohalo." There were no masses in which a lateral shadow was observed. In terms of blood flow signals in the central portion of the mass, pulsatile flow was present in only one mass. CONCLUSIONS: Important ultrasonographic findings of hepatic hemangioma are characterized as the absence of lateral shadow (100%) and no attenuation of posterior echoes (100%), while the presence of a hyperechoic rim is useful for detecting isoechoic hemangioma.