Sonographic diagnosis of fatty liver using a histogram technique that compares liver and renal cortical echo amplitudes.

Accurate diagnosis of fatty liver using ultrasonography was attempted based on the difference between the echo intensities of the liver and kidney determined from ultrasonic histograms. Livers were then classified as having fatty infiltration, normal histology, or intermediate histology based on CT ratios established previously in earlier work comparing non-contrast-enhanced liver and spleen. The hepatorenal difference was significantly greater in the fatty liver group than in the normal liver group (8.9 +/- 2.0 dB vs 2.5 +/- 4.5 dB, p < 0.001). When a hepatorenal difference of > or = 7.0 dB was taken as the criterion, this method had a sensitivity of 91.3%, a specificity of 83.8%, and an accuracy of 86.7% for the diagnosis of fatty liver. Thus, quantitative ultrasonic diagnosis of fatty liver can be performed using echo intensity histograms.