Monoexponential and Biexponential Fitting of Diffusional Magnetic Resonance Imaging Signal Analysis for Prediction of Liver Fibrosis Severity

OBJECTIVE: The objective of this study is to compare the value of monoexponential and biexponential approach to the diffusion-weighted magnetic resonance imaging signal in the prediction of the liver fibrosis. METHODS: Forty patients with hepatitis C were included. Quantification of the apparent diffusion coefficient (ADC) and pure molecular diffusion (D), pseudodiffusion (D*), and perfusion fraction (f) was performed using 9 b values (b = 0, 20, 50, 100, 200, 400, 600, 800, 1000 s/mm). RESULTS: Significant fibrosis was found in 14 subjects. Monoexponentally derived ADC parameters were significantly correlated. Apparent diffusion coefficient calculated from all b values and ADC based on high b values were significantly related to the fibrosis grade (P < 0.02), and none of intravoxel incoherent motion parameters presented such an association. Apparent diffusion coefficient based on high b values was the best predictor of significant fibrosis with area under the curve of 0.81, sensitivity of 0.57, and specificity of 0.92. CONCLUSION: Intravoxel incoherent motion parameters did not allow for prediction of the liver fibrosis. Apparent diffusion coefficient calculated based on high b values presents considerable specificity in predicting significant fibrosis.