Performance of a New Elastographic Method (ARFI technology) Compared to Unidimensional Transient Elastography in the Noninvasive Assessment of Chronic Hepatitis C. Preliminary Results

Abstract

Background and aims: The current study aims to evaluate the performance of a new elastographic method (ARFI) in noninvasive fibrosis assessment and to compare it to another validated technology (transient elastography, TE).

Method: 112 consecutive chronic hepatitis C patients (histologically proven according to the Metavir scoring system: 12.5% F0, 26.6% F1, 16.1% F2, 7.1% F3, 37.5% F4) were prospectively included in this study. They were examined on the same day, using both ARFI (with shear wave velocity - SWV- quantification) and TE (with liver stiffness quantification).

Results: SWV is correlated only with fibrosis (r=0.717, p<0.0001) and necroinflammatory activity (r=0.328, p=0.014), but not with steatosis (r=0.122, p=0.321). There is a significant increase of SWV in parallel with the increase in the fibrosis stage: 1.079±0.150 (F0-F1), 1.504±0.895 (F2), 1.520±0.575 (F3), 2.552±0.782 (F4), p<0.0001, but there is a certain degree of overlap between the consecutive stages F1-F2 (p=0.072), F2-F3 (p=0.965). SWV cut-off values (m/s) that were predictive for each fibrosis stage were: 1.19 (F≥1), 1.34 (F≥2), 1.61 (F≥3) and 2.00 (F4). AUROC for ARFI vs TE were: 0.709 vs 0.902, p=0.006 (F≥1), 0.851 vs 0.941, p=0.022 (F≥2), 0.869 vs 0.926, p=0.153 (F≥3) and 0.911 vs 0.945, p=0.331 (F4).

Conclusions: ARFI allows SWV quantification, in strong correlation with the fibrosis stage. Steatosis does not influence SWV. The maximal performance of the method consists of the prediction in severe fibrosis and cirrhosis. The diagnostic accuracy is strongly comparable to TE only for the prediction of severe fibrosis and cirrhosis, whereas for earlier stages, TE performs better.