AN EVALUATION OF HEPATIC ULTRASOUND SPEED IN INJURY MODELS IN RATS - CORRELATION WITH TISSUE CONSTITUENTS

The speed of sound through the Livers of 32 male Sprague-Dawley rats w as measured. The study population consisted of four experimental group s: control, acute liver injury induced by carbon tetrachloride, fatty liver induced by a choline-deficient diet, and liver cirrhosis induced by administration of N-diethylnitrosamine. To examine possible correl ations between the speed of sound and liver histology, biochemical mea surements of the water, fat, and collagen content were made. The aim o f the present study was to determine the effects of the characteristic s of diseased liver tissue on the speed of sound, by studying the tiss ue constituents biochemically and by using a more accurate measurement of the speed of sound. The sound speed was 1591.6 +/- 6.7 m/s in the acute liver injury group, 1531.4 +/- 18.4 m/s in the fatty liver group , and 1624.9 +/- 6.7 m/s in the liver cirrhosis group. No significant correlation existed between the speed of sound and the water content i n all groups taken together, whereas a good correlation was found in t he fatty liver group (P < 0.0001, r = -0.858) and in cirrhosis (P < 0. 0001, r = 0.760) when the groups were examined separately. These resul ts indicate that the speed of sound is useful for diagnosing fatty liv er for predicting the fat content.