Non invasive evaluation of liver fibrosis in children with chronic liver diseases

ABSTRACT

To noninvasively assess liver fibrosis in children with chronic liver diseases by diffusion weighted MR imaging and 13Cmethacetin-breath test and compare the diagnostic accuracy between these tests referring to hepatic histology as gold standard. Fifty children [31 boys, 19 girls, median age 9.1 years], with chronic liver diseases and 20 age matched volunteers underwent diffusion weighted MR imaging of the liver and13C-methacetin-breath test Liver biopsy was obtained with calculation of METAVIR score. The ADC value of the liver and values of MBT was correlated with METAVIR score. Receiver operating characteristic curve was done for diagnosis and grading of hepatic fibrosis. 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. The cut off point to predict fibrosis [1.7x10-3mm2/s] revealed 84% accuracy, 88% sensitivity, 85% specificity, 81% PPV, and 87% NPV. The area under the curve was 0.91 for F1, 0.85 for F2, 0.86 for F3 and 0.90 for F4. Receiver operating characteristic analysis of the 13C methacetin breath test results revealed a cut-off <1.79 best with 94% sensitivity and 95% specificity in predicting cirrhosis. The area under the receiver operator curve was 0.968. The apparent diffusion coefficient value is a promising quantitative parameter used for diagnosis and quantification of hepatic fibrosis in children with chronic liver diseases. The non-invasive 13C-MBT proved to be safe, easy to perform and reliably differentiates between stages of hepatic fibrosis