Liver fibrosis: evaluation with diffusion-weighted magnetic resonance imaging in patients with chronic liver disease

Liver fibrosis is often a possible evolution of chronic liver disease (CLD), with a risk of progression to cirrhosis. This study was designed to determine if the measure of apparent diffusion coefficient (ADC) is clinically accurate in the staging of fibrosis.

The study was conducted in the period 2008-2012. We recruited 84 patients with CLD. The control group included 67 patients whose laboratory, ultrasound and magnetic resonance imaging exams demonstrated liver's normal conditions. For ethical reasons, these patients did not undergo liver biopsy. Patients were examined using diffusion-weighted magnetic resonance imaging with a 1.5 Tesla magnet and with single shot echo-planar technique. Patients did undergo liver biopsy and the samples were evaluated with the Metavir score (F0-F4), Ishak score (0-6) and Brunt score (0-6). Patients were divided into three groups according to the different degree of fibrosis and the ADC was compared with U-test of Mann-Whitney. Moreover, it was used the analysis Receiver Operating Characteristic (ROC).

A significant difference between group 1 (F0-F1) and group 3 (F3-F4) was found, with P=0.0024 and between group 2 (F2) and group 3, with P=0.027, but there was no significant difference of the ADC values in group 1 and group 2.

The study showed a correlation between reduction of ADC and increasing of liver fibrosis degree. The ADC seems to be useful in staging liver fibrosis in patients with CLD, in particular to distinguish the later stages of fibrosis from early and intermediate stages.