Solid Pancreatic Lesions: Characterization by Using Timing Bolus Dynamic Contrast-enhanced MR Imaging Assessment-A Preliminary Study

Purpose: To assess the feasibility of postprocessing dynamic contrast material-enhanced (DCE) magnetic resonance (MR) imaging timing bolus data by using a three-dimensional radial gradient-echo technique with k-space-weighted image contrast (KWIC) for the characterization of solid pancreatic diseases. Materials and Methods: This retrospective study was approved by the institutional review board, and informed consent was waived. A total of 45 patients suspected of having biliary or pancreatic disease underwent pancreatic MR examination with a 3.0-T imager with a low-dose (2 mL gadopentetate dimeglumine) timing bolus by using the radial KWIC technique. There were 24 patients with pancreatic cancers, eight with pancreatic neuroendocrine tumors (PNETs), three with chronic pancreatitis, and 10 with a normal pancreas. By using a dedicated postprocessing software program for DCE MR imaging, the following perfusion parameters were measured for tumor and nontumorous parenchyma: volume transfer coefficient (K-trans) and extracellular extravascular volume fraction; the rate constant (k(ep)) and initial area under the concentration curve in 60 seconds (iAUC) were then generated. The perfusion parameters acquired on DCE MR images were compared among the groups by using the analysis of variance test. Results: K-trans, k(ep), and iAUC values in patients with pancreatic cancer (0.042 min(-1) +/- 0.023 [standard deviation], 0.761 min(-1) +/- 0.529, and 2.841 mmol/sec +/- 1.811, respectively) were significantly lower than in patients with a normal pancreas (0.387 min(-1) +/- 0.176, 6.376 min(-1) +/- 2.529, and 7.156 mmol/sec +/- 3.414, respectively) (P < .05 for all). In addition, k(ep) values of PNETs and normal pancreas also differed (P < .0001), and K-trans, k(ep), and iAUC values of pancreatic cancers and PNETs differed significantly (P < .0001, P = .038, and P < .0001, respectively). Conclusion: Results of timing bolus DCE MR imaging with the radial KWIC sequence from routine examinations can be post-processed to yield potentially useful perfusion parameters for the characterization of pancreatic diseases. (C) RSNA, 2012