Aim: The present study has developed and evaluated the effectiveness of a new echo attenuation measurement function combined with an ultrasonic diagnostic system for the accurate diagnosis of liver steatosis.
Methods: A multicenter prospective study involving patients with chronic hepatitis was carried out. All patients underwent liver biopsy, and attenuation coefficient (ATT) was measured on the same day. The fat area (%) of biopsy specimens was quantitatively evaluated. Correlations between ATT, steatosis grade, and fat area were evaluated.
Results: A total of 351 patients were enrolled in this study. The median values of fat area for steatosis grades S0, S1, S2, and S3 were 0.6%, 3.2%, 6.4%, and 15.5%, respectively. A significant correlation was found between fat area and steatosis grade (P < 0.001). Similarly, the median values of ATT for steatosis grades S0, S1, S2, and S3 were 0.55, 0.63, 0.69, and 0.85 dB/cm/MHz, respectively, and ATT increased with an increase in the steatosis grade (P < 0.001). Attenuation coefficient was significantly correlated with fat area (r = 0.50, P < 0.001). The area under the receiver operating characteristic curve corresponding to S ≥ 1, S ≥ 2, and S ≥ 3 were 0.79, 0.87, and 0.96, respectively. Similarly, the sensitivity and specificity of S ≥ 1, S ≥ 2, and S ≥ 3 were 72%, 82%, and 87% and 72%, 82%, and 89%, respectively.
Conclusions: The newly developed ATT measurement for evaluation of liver steatosis was closely correlated with steatosis grade and automated quantification of fat area, and it provides clinically relevant information.
Keywords: NAFLD; attenuation measurement; liver steatosis.
© 2018 The Japan Society of Hepatology.