[Diagnosis and quantification of hepatic fibrosis with diffusion weighted MR imaging: preliminary results]

Diagnosis and quantification of hepatic fibrosis are especially important in patients with chronic liver disease. Liver biopsy remains the gold standard for diagnosis of cirrhosis but has several limitations. The purpose of this study was to determine the usefulness of diffusion-weighted MR imaging, for the diagnosis of cirrhosis and quantification of hepatic fibrosis, and to define the best sequence parameters for this evaluation.

Diffusion-weighted imaging using a 1.5 T MR unit was performed in 14 healthy volunteers and 13 cirrhotic patients. Sets of 8 images with different b values (200, 400, 600, and 800 sec/mm2) and different TR (3500 and 5000 ms) were acquired with breath-holding. Apparent diffusion coefficients (ADCs) were calculated. Correlation between Child-Pugh scores, serum hyaluronate concentrations and ADCs were performed.

ADCs were significantly lower in cirrhotic patients (2,055 10-3) compared to controls (2,915 10-3) (p<0.05) when the b value was 200 s/mm2 and the TR was 5000 ms. Significant correlations were observed between Child-Pugh scores and ADCs (p<0.05), and between serum hyaluronate concentrations and ADCs (p<0.05), when the b value was 400 sec/mm2 and the TR was 5000 ms.

Our preliminary study showed that the measurement of ADCs has good potential for diagnosis and quantification of hepatic fibrosis, especially when using b values of 200 sec/mm2 and 400 sec/mm2.