Intravoxel Incoherent Motion MRI of the Healthy Pancreas: Monoexponential and Biexponential Apparent Diffusion Parameters of the Normal Head, Body and Tail

BackgroundTo investigate the monoexponential and biexponential apparent diffusion parameters in different anatomical regions of the healthy pancreas using intravoxel incoherent motion (IVIM) diffusion weighted imaging (DWI). MethodsFifty-seven healthy volunteers (age, 45.010.8 years) were recruited. DWI of the pancreas was performed with 9 b-values (0, 20, 50, 100, 200, 400, 600, 800, and 1000 s/mm(2), respectively). The ADC was calculated for all b-values using linear regression yielding ADC(total). The ADC(b) value of the monoexponential DWI, slow component of diffusion (ADC(slow)), incoherent microcirculation (ADC(fast)) and perfusion fraction (f) of the biexponential DWI were calculated for the pancreas head, body and tail. Dependency of the parameters on the anatomical regions was analyzed using Friedman test. ResultsAll of the mean ADC(400), ADC(600), ADC(800), ADC(1000), ADC(total) and f values differed significantly among the anatomical regions with the lowest values were observed in the tail of pancreas (P<0.05). The Friedman test results demonstrated a significant decline of the mean ADC values of the monoexponential DWI from b(20) to b(1000) for the three anatomical regions respectively (P<0.001). ConclusionMulti-b-value DWI derived quantitative parameters including ADC(400), ADC(600), ADC(800), ADC(1000), ADC(total), and f differed significantly among the pancreatic head, body and tail, with the lowest values obtained in the tail. J. Magn. Reson. Imaging 2015;41:1236-1241. (c) 2014 Wiley Periodicals, Inc.