Branch duct-type intraductal papillary mucinous tumor: diagnostic value of multiplanar reformatted images in multislice CT.

The object of this study was to evaluate the usefulness of high-resolution multiplanar reformatted (MPR) images obtained by multislice CT in demonstrating connection between pancreatic cystic lesions and the main pancreatic duct. The study included 27 lesions with connection to the main pancreatic duct and 12 lesions without. All but one of the former lesions were branch duct-type intraductal papillary mucinous tumors (IPMTs). Oblique and curved MPR images with 0.5 mm continuous slices were generated from pancreatic-phase axial images reconstructed with 0.5 mm or 1 mm thickness at 0.5 mm intervals over a 260 mm field of view. The diagnostic capabilities for demonstrating connection with the main pancreatic duct were compared among axial images, MPR images, and both axial and MPR images in combination using the Brier score. The diagnosis in MPR images for demonstrating connection was more certain than that in axial images (P<0.05). Compared with MPR images alone, the use of both axial and MPR images resulted in further improvements in diagnostic performance, although the difference was not statistically significant. The use of high-resolution MPR images significantly improves diagnostic performance for demonstrating connection between pancreatic cystic lesions and the main pancreatic duct, which is useful for the diagnosis of branch duct-type IPMT.