Quantitative ultrasonography of the liver in cats during obesity induction and dietary restriction

A study was designed to evaluate quantitative ultrasonographic characteristics of a diffuse parenchymal disease in an experimental model of subclinical fatty infiltration of the liver using diet-induced obesity and dietary restriction in the cat. Ultrasound images of livers were quantitatively analysed by a video signal analysis technique before, during and at the end of obesity induction, and then during and following dietary restriction. Attenuation and brightness (backscatter coefficient) were correlated with hepatic lipid content obtained from the livers by surgical and ultrasound-guided percutaneous biopsy. Attenuation and backscatter increased as hepatic lipid content increased. Both attenuation and backscatter significantly correlated with the hepatic lipid content (P=0·002 and P=0·02 respectively). This model of subclinical fatty infiltration of the liver in the cat demonstrates that hepatic lipid content increases as a consequence of obesity and of severe dietary restriction. Infiltration of the liver with fat may be evaluated non-invasively using quantitative ultrasonography by the video signal analysis technique. This method of image analysis may prove useful for the evaluation of diffuse parenchymal organ disease.