Diffusion-weighted Imaging Magnetic Resonance for Assessing Liver Fibrosis in Patients With Chronic Viral Hepatitis

Among patients with chronic infection with hepatitis B virus or hepatitis C virus, evaluation of the stage of liver fibrosis is of major importance for determining prognosis and therapeutic decisions. Liver biopsy is a costly and invasive technique with associated mortality and morbidity. A typical biopsy fragment represents only 1/50,000 of the organ. Several noninvasive radiological techniques have been investigated for the diagnosis of liver fibrosis and cirrhosis. Diffusion-weighted magnetic resonance imaging (DW-MRI) is a particularly appealing method for the diagnosis of liver fibrosis. Because it is easy to implement, non-operator dependent, and process without the need for contrast agents. However, preliminary studies on small numbers of patients in which various hardware and sequencing profiles were used have reported inconsistent results for staging liver fibrosis with DW-MRI. The aims of this study are to evaluate correlation between stage of hepatic fibrosis and liver apparent diffusion coefficient (ADC) and normalized liver ADC with spleen assessed by DW-MRI in patients with chronic viral hepatitis B or C. Also, this study aim to evaluate factors that influence liver ADC and normalized liver ADC with spleen value for predicting the stage of liver fibrosis as well as to estimate the optimal cutoff values of DW-MRI for determining significant liver fibrosis (fibrosis stage ≥2) and advanced fibrosis (fibrosis stage ≥3).