Serial change of liver stiffness measured by acoustic radiation force impulse imaging in chronic liver disease: correlation with biochemical markers.

PURPOSE: In patients with chronic diffuse liver diseases, liver fibrosis severity is an important element for prognosis and for selecting therapy. Acoustic radiation force impulse (ARFI) imaging techniques were recently developed to measure liver fibrosis, but their specificity is impaired by cholestasis, inflammation, or edema in acute hepatitis. Herein, our objectives were to evaluate serial changes in shear wave velocity (SWV) and to correlate these changes with biochemical activity. METHODS: This study included 108 patients who underwent ARFI because of viral hepatitis [hepatitis B (HBV) or C (HCV)] with serial follow-up after 3-6 months at our institution between August 2011 and May 2013. Based on baseline and follow-up ARFI, we divided patients with HBV and HCV into two groups: a decreasing SWV group and a non-decreasing SWV group. We evaluated serial SWV changes and correlated these changes with biochemical activity changes. RESULTS: The patients were divided into SWV groups as follows: decreasing SWV group (HBV, n = 23; HCV, n = 7) and non-decreasing SWV group (HBV, n = 40; HCV, n = 38). In both HBV and HVC patients, aspartate aminotransferase (AST) and alanine aminotransferase (ALT) were significantly decreased at follow-up in the decreasing SWV group. CONCLUSIONS: The liver stiffness value assessed by ARFI became lower over time in patients who had decreasing AST and ALT levels. According to this study, ARFI overestimates fibrosis grade in patients with high AST and ALT. Thus, assessment of liver fibrosis by ARFI elastography should include consideration of biochemical markers such as AST and ALT levels and additional follow-up using ARFI elastography.

Comparative study of shear wave velocities using acoustic radiation force impulse technology in hepatocellular carcinoma: the extent of radiofrequency ablation.

BACKGROUND/AIMS: The purpose of this study was to assess the value of acoustic radiation force impulse (ARFI) for predicting the extent of radiofrequency ablation (RFA) in hepatocellular carcinoma (HCC) by correlating the elasticity of HCC and peritumoral parenchyma (as measured by ARFI) with the extent of ablation determined by computed tomography (CT). METHODS: From September 2009 to June 2011, 158 patients underwent RFA ablation for HCC (single, ≤3 cm). We evaluated the data of a total of 38 prospectively enrolled patients who underwent both ARFI imaging and contrast-enhanced CT after one session of 12 minutes of RFA without a change in needle position. The ARFI imaging indices, including the mean shear wave velocity (SWV) of HCC, mean SWV of the peritumoral parenchyma and tumor size, were evaluated to determine the statistical correlation with RFA extent after one session of 12 minutes of RFA. RESULTS: A stiffer liver parenchyma in patients with cirrhosis results in a smaller ablation zone. CONCLUSIONS: SWV of ARFI in liver parenchyma was well correlated with RFA extent. After evaluating the correlation between ARFI and RFA extent, we suggest that the SWV in liver parenchyma might be a non-invasive supplementary tool for predicting the extent of RFA.

Acoustic radiation force impulse elastography for hepatocellular carcinoma-associated radiofrequency ablation.

AIM: To evaluate the potential usefulness of acoustic radiation force impulse (ARFI) images for evaluation of hepatocellular carcinomas (HCC)-associated radiofrequency ablation. METHODS: From January 2010 to June 2010, a total of 38 patients with HCC including recurred HCCs after RFA underwent ARFI elastography. The brightness of tumor was checked and the shear wave velocity was measured for the quantification of stiffness. According to the brightness, the tumors were classified as brighter, same color and darker compared with adjacent parenchyma. Using the same methods, 8 patients with recurred HCCs after RFA state were evaluated about the brightness compared with adjacent RFA ablation area. RESULTS: In the 38 patients with HCCs, 20 (52.6%) were brighter than surrounding cirrhotic parenchyma. Another 13 (34.2%) were darker. The others (5 cases, 13.2%) were seen as the same color as the adjacent liver parenchyma. Post-RFA lesions were darker than previous tumor and surrounding parenchyma in all 38 cases. However, recurred HCCs were brighter than the treated site in all 8 cases. CONCLUSION: Using ARFI technique is helpful for differential diagnosis in order to detect recurred HCCs more easily in patients with confusing status.