New diagnostic technique to evaluate hepatic steatosis using the attenuation coefficient on ultrasound B mode.

Abstract

We have developed a diagnostic technique to evaluate hepatic steatosis using the attenuation coefficient (ATT) in ultrasound B mode imaging. A controlled attenuation parameter (CAP) by vibration-controlled transient elastography (VCTE) has also been used to evaluate hepatic steatosis. As that method uses ultrasound A mode, visualizing the liver in real time is difficult. We designed this clinical study to evaluate the diagnostic advantage of our technique using ATT compared to CAP. The study group included 94 patients with chronic liver disease who had undergone both ATT and CAP assessment at the time of liver biopsy. The M-probe and XL-probe were used for CAP measurement. Data for ATT and CAP were compared as a function of the steatosis grade. The area under the receiver operating characteristic curve (AUC-ROCs) for ATT and PAC as a function of the steatosis grade were as follows: grade 1, 0.74 and 0.81; grade 2, 0.80 and 0.85; and grade 3, 0.96 and 0.98, respectively. The accuracy of steatosis grade diagnosis using ATT was the same as that using CAP, with no significant differences and with the added advantage of B mode ultrasound being more convenient and rapid, compared to A mode ultrasound, particularly for patients with subcutaneous fat thickness ≥2 cm.