Objective: To investigate the diagnostic value of magnetic resonance diffusion-weighted imaging (DWI) technique in assessing the disease activity and liver fibrosis of chronic viral hepatitis.
Methods: A 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.
Results: The 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).
Conclusion: DWI is a valuable method for in vivo and noninvasive assessment of the disease activity and liver fibrosis of chronic viral hepatitis.