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

Abstract

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. 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). 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. These findings suggest that ARFI measurement may be a reliable method for predicting the severity of fibrosis after a Kasai operation.