Comparison of attenuation and liver‐kidney contrast of liver ultrasonographs with histology and biochemistry in dogs with experimentally induced steroid hepatopathy

Abstract
Digital analysis of liver ultrasound images (USGs) was compared to histological and serum enzyme activity results in dogs with steroid‐induced hepatopathy. Steroid hepatopathy was used as a model for diffuse liver diseases. Prednisolone administration n resulted in increased acoustic backscatter (hyperechogenicity) of the liver with reference to the kidney and significant depth attenuation (hyper‐attenuation). Absolute changes were determined by histogram analysis of echo means (Ems) of area samples (1x1cm) of liver and kidney at the depth of 2 cm (liver‐kidney contrast) and at 2 cms and 4 cm (depth attenuation). Liver‐kidney contrast histograms correlated well with histology but were more sensitive than serum enzyme activity and subjective visual interpretation. Depth attenuation was the earliest detectable acoustic change. These results suggested that depth attenuation is an early and sensitive indicator of steroid hepatopathy. Liver‐kidney contrast correlates well with histology and may complement biopsy examination during follow‐up studies.