Pancreatic ductal adenocarcinoma and chronic mass-forming pancreatitis: Differentiation with dual-energy MDCT in spectral imaging mode

•Dual-energy MDCT in spectral imaging mode may help to detect pancreatic lesions.•Dual-energy MDCT in spectral imaging mode may help differentiate mass-forming chronic pancreatitis (CMFP) from pancreatic ductal adenocarcinoma (PDAC).•Quantitative analysis of iodine concentration provides greater diagnostic confidence.•Treatment and management can be given with greater confidence.

ObjectiveTo investigate the value of dual-energy MDCT in spectral imaging in the differential diagnosis of chronic mass-forming chronic pancreatitis (CMFP) and pancreatic ductal adenocarcinoma (PDAC) during the arterial phase (AP) and the pancreatic parenchymal phase (PP).Materials and methodsThirty five consecutive patients with CMFP (n = 15) or PDAC (n = 20) underwent dual-energy MDCT in spectral imaging during AP and PP. Iodine concentrations were derived from iodine-based material-decomposition CT images and normalized to the iodine concentration in the aorta. The difference in iodine concentration between the AP and PP, contrast-to-noise ratio (CNR) and the slope K of the spectrum curve were calculated.ResultsNormalized iodine concentrations (NICs) in patients with CMFP differed significantly from those in patients with PDAC during two double phases (mean NIC, 0.26 ± 0.04 mg/mL vs. 0.53 ± 0.02 mg/mL, p = 0.0001; 0.07 ± 0.02 mg/mL vs. 0.28 ± 0.04 mg/mL, p = 0.0002, respectively). There were significant differences in the value of the slope K of the spectrum curve in two groups during AP and PP (KCMFP = 3.27 ± 0.70 vs. KPDAC = 1.35 ± 0.41, P = 0.001, and KCMFP = 3.70 ± 0.17 vs. KPDAC = 2.16 ± 0.70, p = 0.003, respectively). CNRs at low energy levels (40–70 keV) were higher than those at high energy levels (80–40 keV).ConclusionIndividual patient CNR-optimized energy level images and the NIC can be used to improve the sensitivity and the specificity for differentiating CMFP from PDAC by use of dual-energy MDCT in spectral imaging with fast tube voltage switching.