[Establishment of an ultrasonographic method for evaluating the hepatic lipid accumulation in mice]

To investigate the semi-quantitative method for evaluating lipid accumulation in livers, male C57BL/6J mice (CON), HFD mice characterized with the mild fatty liver induced by high-fat diet, and KKAy mice charactered with the moderately severe fatty liver induced by high-caloric diet were used. The lipid accumulation was estimated by the histological examination (HE staining) and the content of hepatic triglyceride, separately. Echo-intensity of two selected regions along the ultrasound transmission direction was recorded using a small animal ultrasonographic system, and the echo-intensity attenuation coefficient was calculated. Correlation between the echo-intensity attenuation coefficient and the content of hepatic triglyceride was analyzed by the Spearman's rank correlation analysis. The results showed that the lipid accumulation in livers increased significantly in both HFD and KKAy mice compared with CON mice and it was more serious in KKAy mice than that in HFD mice. The values of echo-intensity attenuation coefficient were also increased in sequence according to group. These values were positively associated with the content of hepatic triglyceride (r = 0.744, P < 0.01). In conclusion, the echo-intensity attenuation coefficient is a simple, impersonal, and non-invasive method for evaluating the hepatic lipid accumulation. It can be used to research the process and the treatment of fatty liver diseases in mice.