Can high-b-value diffusion weighted imaging differentiate between pancreatic cancer, mass forming focal pancreatitis and normal pancreas?

PurposeTo investigate whether high-b-value diffusion weighted imaging (DWI) and the apparent diffusion coefficient (ADC) values can differentiate pancreatic cancer (PC), mass forming focal pancreatitis (MFFP), and normal pancreas.Patients and methodsDiffusion weighted MR imaging (b = 0 and 800 s/mm2) was performed in 21 patients with histopathologically-proven pancreatic cancer, 19 patients with mass forming focal pancreatitis proven by histopathology and/or clinical follow up, and 21 normal control subjects. The signal intensity on DWI was visually evaluated and the ADC values of the pancreatic masses, the remaining pancreas, and the normal pancreas were measured and compared.ResultsOn high-b-value (800 s/mm2) DW images, PC was slightly more hyperintense, relative to the remaining pancreas, than MFFP. The mean ADC value for PC (1.22 ± 0.101 × 10−3 mm2/s) was significantly lower than the remaining pancreas (1.99 ± 0.206 × 10−3 mm2/s; P < 0.001), MFFP (1.53 ± 0.122 × 10−3 mm2/s; P < 0.001), and the pancreatic gland in the control group (1.79 ± 0.061 × 10−3 mm2/s; P < 0.001). There was also a significant difference between the mean ADC values of MFFP and the remaining pancreas (1.53 ± 0.122 vs 1.89 ± 0.169 × 10−3 mm2/s; P < 0.001).ConclusionDifferences on DWI and ADC measurements help to differentiate pancreatic cancer, mass forming focal pancreatitis, and normal pancreas.