Diffusion-weighted MRI of the pancreas: Correlation with secretin endoscopic pancreatic function test (ePFT)

Rationale and Objectives. To evaluate the correlation between apparent diffusion coefficient (ADC) values of the pancreas on diffusion-weighted imaging (DWI) and pancreatic exocrine function determined by HCO3 concentration in the secretin endoscopic pancreatic function test (ePFT). Materials and Methods. Mean ADC values derived from 10 different points of the pancreatic gland on DWI were reviewed in 14 patients with normal (peak HCO3 >= 80 mEq/L) and 14 patients with abnormal (peak HCO3 <80 mEq/L) ePFT results. Magnetic resonance cholangiopancreatography (MRCP) images of the same patients were evaluated for the diagnosis of chronic pancreatitis. Correlation between ADC values and HCO3 concentration as well as Cambridge scores in MRCP was performed using Spearman's correlation test. Results. Mean ADC value of the pancreas was 1.52 +/- 0.13 x 10(-3) mm(2)/s in patients with abnormal ePFT results and 1.78 +/- 0.07 x 10(-3) mm(2)/s in the normal group. There was a significant statistical difference between the ADC values of the pancreas in the two groups (P < .0001). There was also a statistically significant correlation between HCO3 level and ADC value of the pancreas in the study patients (r = 0.771. P <.0001). Morphologic changes of the pancreas according to the Cambridge classification were also well correlated with the mean ADC values (r = -0.763, P < .0001). Conclusions. Strong correlation between ADC value and pancreatic exocrine function as well as Cambridge score for chronic pancreatitis exists. Further studies are needed to determine the cut off ADC value for chronic pancreatitis.