Comparison Between Dual Energy/Subtraction CT With MRI for the Identification of Predictors of Malignancy in Cystic Pancreatic Lesions

Cystic pancreatic lesions are increasingly detected incidentally in imaging studies, reportedly in up to 45% of the abdominal Magnetic Resonance (MR) examinations. The majority of these lesions have potential to become cancer, therefore requiring surgery or imaging follow-up to monitor the development of features indicative of malignant transformation. Abdominal MR is the current standard of care for the follow-up of pancreatic cysts (PCs). However, MR is expensive and access is limited, In our institution, more than 35 MR studies for assessment of PCs were performed each month in 2015, placing a significant burden on the health care system that includes contributing to longer MR wait times for other indications. The investigators will compare MR to two new computed tomography (CT) techniques - dual energy CT (DECT) and Subtraction imaging - with regards to their ability to detect features associated with increased risk of malignancy (enhancing septa and mural nodules) in PCs. For cases where there is disagreement between these 2 CT techniques and MR, histopathology of the surgical specimen or the results of Endoscopic Ultrasound (EUS) will serve as reference standard. Using DECT or Subtraction instead of MR for the assessment and follow-up of PCs would save significant healthcare costs and MR slots, which could be released to other indications and to reduce waiting times. Furthermore, if DECT and/or Subtraction imaging end up demonstrating to be superior to MR for this purpose, patients with cystic pancreatic lesions could have a direct benefit.