Hirosaki Med．J.　65：199―208，2014 ORIGINAL ARTICLE NON-INVASIVE QUANTIFICATION OF LIVER DAMAGE BY A NOVEL APPLICATION FOR STATISTICAL ANALYSIS OF ULTRASOUND SIGNALS

Abstract Aim: Hepatic steatosis is a major cause of steatohepatitis and is observed in several diffuse liver diseases. We studied the efficacy of a novel ultrasound application, acoustic structure quantification （ASQ）, for analyzing the amount of fat deposition in the liver parenchyma. Methods: Forty-three patients who received a hepatectomy at our institution participated in this study. An ultrasound machine equipped with a software application for ASQ was used to detect steatosis prior to surgery. Non-tumoral liver parenchyma obtained by hepatectomy was pathologically evaluated according to the three-grade system. Results: Histopathologically, twenty-three patients did not present steatosis, seventeen presented grade 1, and the remaining three presented grade 2 steatosis. The median “focal disturbance ratio ” （FD-ratio）, a representative index obtained by ASQ, decreased with the steatosis grade, from 0.157 （range: 0.039-0.410 ） at steatosis grade 0, 0.085 （range: 0.021-0.159 ） at steatosis grade 1, and 0.039 （range: 0.021-0.048 ） at steatosis grade 2. There were significant differences in the FD-ratio between steatosis grades 0 and 1 and between steatosis grades 0 and 2 （p = 0.001 and p = 0.007, respectively）. Conclusions: ASQ can be useful during a quantitative examination of the fat accumulation in the liver parenchyma and offers a reliable marker for the early detection of liver injury. Hirosaki Med．J. 65：199―208，201