Differentiation of pancreas carcinoma from healthy pancreas using diffusion-weighted MR imaging: comparison of apparent diffusion coefficient and intravoxel incoherent motion-derived parameters

Abstract

Objective To evaluate the diagnostic performance of multi-b value DWI to differentiate pancreatic adenocarcinoma from healthy pancreas using the apparent diffusion coefficient (ADC) and parameters derived from the intravoxel incoherent motion (IVIM) theory. Methods Forty-eight patients with histopathologically proven pancreatic adenocarcinoma and fifty patients with healthy pancreas were examined at 3.0 Tesla using a single-shot echo-planar imaging DWI pulse sequence. Eight b-values ranging from 0 to 1 000 s/mm2 were used. ADC, diffusion coefficient (D), perfusion-related diffusion (D*) and perfusion fraction (f) were compared between pancreatic adenocarcinoma and healthy pancreas, t test or Mann-Whitney U test was used to compare the MRI parameters, ROC was used to evaluate the diagnostic efficiency. Results In comparison to healthy pancreatic tissue, a significant reduction of the ADC, D* and f was found in pancreatic adenocarcinoma [healthy pancreatic tissue: (1.68±0.31)×10-3mm2/s, 27.10×10-3mm2/s, (36.92±12.47)%; pancreatic adenocarcinoma: (1.51±0.37)×10-3mm2/s, 13.90×10-3mm2/s, (30.06±19.84)%] (P 0.05). In the ROC-analyses, the area under curve for D* was the largest (0.727), followed by f and ADC in order (0.680 and 0.669). Conclusion Using the IVIM DWI approach, the D*, f and ADC value are useful for differentiating pancreatic adenocarcinoma from healthy pancreatic tissue. Key words: Pancreatic neoplasms; Magnetic resonance imaging; Comparative study