The role of MRCP in characterizing ductal communication and high-risk features in pancreatic cystic lesions.

Pancreatic cystic lesions are increasingly detected due to the widespread use of high-resolution cross-sectional imaging, particularly MRI and CT. The reported prevalence of incidental pancreatic cysts is 2% to 13% on CT and 20% to 45% on MRI, reflecting improved imaging sensitivity and an aging population. While most cysts are benign, mucinous lesions such as intraductal papillary mucinous neoplasms (IPMNs) and mucinous cystic neoplasms (MCNs) carry a risk of malignant transformation. MRI with MR cholangiopancreatography (MRCP) is central to evaluating pancreatic cystic lesions, particularly for delineating pancreatic duct anatomy, showing cyst-duct communication, and assessing ductal morphology relevant to malignancy risk. High-resolution 3D MRCP enables detailed visualization of the main and branch ducts and supports differentiation of cyst types, including identification of branch-duct IPMN (BD-IPMN) based on communication with the main pancreatic duct. However, MRCP alone has limitations, such as inability to assess enhancement patterns, vascularity, or subtle mural nodules, which may require contrast-enhanced MRI or endoscopic ultrasound (EUS). Recent advances in MRI technology, including compressed sensing and deep-learning reconstruction, have improved MRCP image quality and enabled abbreviated MRI protocols for surveillance of low-risk cysts. These protocols reduce scan time and cost while keeping diagnostic accuracy but must be applied judiciously to avoid missing subtle high-risk features or concomitant malignancies. This review evaluates the role of MRCP in characterizing ductal communication and high-risk features in pancreatic cystic lesions, discusses technical considerations and diagnostic challenges, and examines the evidence supporting abbreviated MRI protocols. The integration of MRCP into multimodality imaging strategies is emphasized for best risk stratification and clinical management.