OBJECTIVETo investigate the diagnostic value of magnetic resonance diffusion-weighted imaging (DWI) technique in assessing the disease activity and liver fibrosis of chronic viral hepatitis.

METHODSA total of 49 patients with chronic viral hepatitis who received liver biopsy and 10 healthy volunteers were included in this study. All of them underwent DWI on a 3.0 T magnetic resonance imaging system. When the gradient factor b value was set at 100, 200, 400, 600, and 800 s/mm2, the apparent diffusion coefficient (ADC) of the liver was measured respectively. Biopsy specimens were scored for necroinflammation and liver fibrosis according to the Knodell histological activity index.

RESULTSThe ADC values of the right lobe in both controls and patients were lower than those of the left lobe. When the b value was set at 400, 600, and 800 s/mm2, the differences of the ADC values between the fibrosis group (n = 36) and the non-fibrosis group (n = 23, including 10 cases of normal subjects) were statistically significant (P < 0.01). When the b value was set at 800 s/mm2, the ADC values among the different degrees of necroinflammation and grades of liver fibrosis were also significantly different (P < 0.05, P < 0.01).

CONCLUSIONDWI is a valuable method for in vivo and noninvasive assessment of the disease activity and liver fibrosis of chronic viral hepatitis.