Diagnosis and quantification of hepatic fibrosis in children with diffusion weighted MR imaging.

Purpose: To evaluate the accuracy of diffusion weighted MR imaging in diagnosis and quantification of hepatic fibrosis in children with chronic hepatitis.

Materials And Methods: Sixty-three consecutive children (40 boys, 23 girls, median age 9.3 years), with chronic hepatitis and thirty age matched volunteers underwent diffusion weighted MR imaging of the liver using a single shot echoplanar imaging with b-value=0, 250, and 500s/mm(2). Liver biopsy was obtained with calculation of METAVIR score. The ADC value of the liver was correlated with METAVIR score. Receiver operating characteristic curve was done for diagnosis and grading of hepatic fibrosis.

Results: There was statistical difference in the mean ADC value between volunteers and patients with hepatic fibrosis (P=0.001) and in patients with different grades of METAVIR scores (P=0.002). There was correlation between the mean ADC value and METAVIR score (r=0.807, P=0.001). The cut off point to predict fibrosis (1.7×10(-3)mm(2)/s) revealed 83% accuracy, 85% sensitivity, 82% specificity, 83% PPV, and 85% NPV. The area under the curve was 0.91 for F1, 0.85 for F2, 0.86 for F3 and 0.90 for F4.

Conclusion: The apparent diffusion coefficient value is a promising quantitative parameter used for diagnosis and quantification of hepatic fibrosis in children with chronic hepatitis.