[Real-time tissue elastography in chronic liver disease].

Background/aim: In patients with chronic liver diseases, the histological classification of liver fibrosis is essential for predicting prognosis and selecting appropriate antiviral therapy. This study aimed to determine the usefulness of a new noninvasive method for the assessment of liver fibrosis by using real-time tissue elastography, which can be performed with conventional ultrasound probes.

Methods: Thirty-nine patients who had liver fibrosis and had undergone liver resection or liver biopsy were included in this study. The surgical specimens obtained were examined to determine the histological stage of liver fibrosis. The strain ratio of subcutaneous fat tissue to liver tissue was calculated. We examined the correlation between the strain ratio and the histological liver fibrosis stage, and compared the utility with various surrogate liver fibrosis markers.

Results: The strain ratio significantly differed with the stage of liver fibrosis, and they had significant correlation (Kruskal-Wallis test: p<0.0001; Spearman's rank correlation, p<0.0001, r=0.797). We identified 5.8 and 3.7 as the cutoff values of strain ratio for the diagnosis of cirrhosis and significant fibrosis. The sensitivity at these values was 92.9% and 81.9% respectively; the specificity, 96.0% and 88.9%; and the areas under the receiver operating characteristic curve (AUROCs), 0.977 and 0.913, respectively. The AUROC was superior to the other surrogate liver fibrosis markers tested.

Conclusions: Real-time tissue elastography is a useful method for the diagnosis of significant fibrosis and cirrhosis in patients with chronic liver diseases.