Low-/high-frequency ultrasound study of liver parenchyma morphology to determine diagnostic utility for extent of liver fibrosis in patients with chronic hepatitis

ObjectiveTo determine whether subtle changes in hyperechoic findings from low-/high-frequency ultrasound analysis of liver biopsy specimens from patients with chronic hepatitis correlate with differences in liver parenchyma morphology associated with presence and extent of fibrosis. MethodsSpatially-matched liver parenchyma biopsy specimens from 216 patients with chronic hepatitis (hepatitis b virus infection) were subjected to both low- and high-frequency ultrasound, as well as conventional histological analysis, which was used to score the extent of fibrosis (progressive staging: S1, no fibrosis, through S4, cirrhosis). The low- and high-frequency point-like echo and echo performance, respectively, were used to classify samples among one of five fractionating features (fine, thick, coarse/crude, irregular/nonlinear, cable stripes). Significance of intergroup differences was assessed by Chi-squared test. Spearman′s correlation coefficient was used to assess the correlation between the ultrasound findings and histological fibrosis stage. ResultsThe changes in echoic findings paralleled progressive deterioration in fibrosis stage: from fine to thicker, uneven, and cable stripe shapes along stages S0 to S4. Both the low- and high-frequency ultrasound findings could differentiate changes in liver parenchyma morphology associated with S1 (low-frequency: χ2=76.52 vs. S2, χ2=71.91 vs. S3, χ2=59.43 vs. S4; high-frequency: χ2=76.52 vs. S2, χ2=71.91 vs. S3, χ2=59.43 vs. S4; all P＜0.01) and S2 (low-frequency: χ2=5.17 vs. S3, χ2=21.25 vs. S4; high frequency: χ2=23.67 vs. S3, χ2=3480 vs. S4; all P＜0.01). There were no significant differences associated with either low- or high-frequency ultrasound findings for S3 or S4. The low- and high-frequency ultrasound liver parenchyma fractionation were postively correlated to liver fibrosis staging (r=04858 and r=0.5513, respectively). The high-frequency ultrasound had a significantly higher positive rate of detecting nodules than the low-frequency ultrasound (61.67% vs. 27.31%; χ2=49.96, P＜0.01), and the positive rates were positively correlated with liver fibrosis stage (low-frequency: r=0.5437; high-frequency: r=0.3021). ConclusionWhile both low- and high-frequency ultrasound allow for detection of liver fibrosis and differentiation of some fibrotic stages, the high-frequency ultrasound findings are superior for detecting fibrotic nodules.