Correlations of sound speed with tissue constituents in normal and diffuse liver disease.

The speed of sound in normal and diffusely-diseased liver specimens was measured. There were four experimental groups, consisting of normal (n = 21), fatty (n = 7), fibrotic (n = 7) and mixed fatty and fibrotic (n = 9). These classifications were based on histological grading. We found that the results corroborate and extend most of the results of Bamber and coworkers. Specifically, no significant correlation was found between speed of sound and fibrosis score; a moderate correlation was found between speed of sound and tissue water content; and a relatively good correlation (r = -0.670, p less than 0.1%) was found between the speed of sound and the histological fat score, which increased to r = -0.819 (p less than 0.1%) when a correction for variations in water content was used.