Liver Apparent Diffusion Coefficient Changes during Telaprevir-Based Therapy for Chronic Hepatitis C.

Background: Diffusion-weighted imaging (DWI) has become an established diagnostic modality for the evaluation of liver parenchymal changes in diseases such as diffuse liver fibrosis. Aims: To evaluate the parenchymal apparent diffusion coefficient value (ADC) changes using diffusion-weighted imaging (DWI) during telaprevir-based triple therapy. Study Design: Diagnostic accuracy study. Methods: Seventeen patients with chronic hepatitis C virus (HCV) virus and twenty-five normal volunteers were included. All of the patients took 12-weeks of telaprevir-based triple therapy followed by 12-weeks of PEGylated interferon and ribavirin therapy. They were examined before treatment (BT), as well as 12-weeks (W12) and 24-weeks (W24) after treatment by 3 Tesla magnetic resonance imaging (MRI). DWI was obtained using a breath-hold single-shot echo-planar spin echo sequence. Histopathologically, liver fibrosis was classified in accordance with the modified Knodell score described by Ishak. Quantitatively, liver ADCs were compared between patients and normal volunteers to detect the contribution of DWI in the detection of fibrosis. In addition, liver ADCs were compared during the therapy to analyze the effect of antiviral medication on liver parenchyma. Results: The liver ADC values of fibrotic liver parenchyma were significantly lower than those of the healthy liver parenchyma (p<0.001). However, we were not able to reach a sufficiently discriminative threshold value. The ADC values showed a declining trend with increasing fibrotic stage. No statistically significant correlation (p=0.204) was observed. Compared with those before treatment, the liver ADC values after telaprevir-based triple therapy were significantly decreased at W12. A significant increase in the liver ADC values was also observed after the cessation of telaprevir therapy at W24 with a return to initial values. Conclusion: Liver ADC values appear to indicate the present but not the stage of liver fibrosis. DWI may be a helpful research tool for the assessment of antiviral drug effects.