Acoustic Radiation Force Impulse Elastography for Chronic Liver Disease: Comparison with Ultrasound-Based Scores of Experienced Radiologists,Child-Pugh Scores and Liver Function Tests

The purpose of our study was to investigate whether acoustic radiation force impulse (ARFI) elastography provides better diagnostic performance for diagnosis of chronic liver disease and correlates better with Child-Pugh scores and liver function tests, compared with an ultrasound (US) scoring system based on visual assessment of conventional B-mode US images by experienced radiologists. Five hundred and twenty-one patients with clinically proven chronic liver disease (n = 293), fatty liver (n = 95) or normal liver (n = 133) were included in this study. B-mode liver US and ARFI elastography were performed in all patients. ARFI elastography was performed at least five times, with each measurement obtained at a different area of the right hepatic lobe; mean shear wave velocity (SWV) was calculated for each patient. The mean SWV was compared with US-based scores from two radiologists (based on liver surface nodularity, parenchyma echotexture and hepatic vein contour), Child-Pugh scores and liver function tests. The mean SWV of the normal liver group was 1.08 m/s ± 0.15; of the fatty liver group, 1.02 m/s ± 0.16; and of the chronic liver disease group, 1.66 m/s ± 0.60 (p < 0.001). The area under the receiver operating characteristics curve of the mean SWV in ARFI elastography was significantly higher than that of the conventional B-mode US-based scores by two radiologists (0.89 vs. 0.74 and 0.77, p < 0.05), with a sensitivity of 75.4% and a specificity of 89.5% at the cut-off value of 1.22 m/s. The sensitivity of the mean SWV was significantly higher than the US-based scores (p < 0.001), although the specificity was not (p > 0.05). The mean SWV was better correlated with Child-Pugh scores and all liver function tests (except total protein) than the US-based scores from two radiologists. In conclusion, ARFI elastography showed better diagnostic performance than visual assessment of experienced radiologists for diagnosis of chronic liver disease, as well as for evaluation of the severity of chronic liver disease. (E-mail: leejy4u@snu.ac.kr)