Utility of multidetector row CT in diagnosing branch duct IPMNs of the pancreas compared with MR cholangiopancreatography and endoscopic ultrasonography.

This study aimed to compare the usefulness of multidetector row CT (MDCT), MR cholangiopancreatography (MRCP), and endoscopic ultrasonography (EUS) in diagnosing branch duct intraductal papillary mucinous neoplasms (IPMNs) of the pancreas. Imaging and pathological findings were retrospectively evaluated for 25 patients with branch duct IPMNs of the pancreas who underwent surgical resection (13 adenomas, 4 borderline lesions, and 8 carcinomas). MDCT and MRCP were performed on all 25 patients, whereas EUS was performed on 22 patients. MDCT and MRCP were used to identify features predictive of malignancy, including carcinoma, borderline lesions, and the presence of thickened irregular walls/septa or a solid mass. EUS was used to identify the presence of intramural nodules or a solid mass. Correlations between histopathology and maximum diameter of the main pancreatic duct (MPD) or cyst size detected by MDCT and MRCP were also examined. Presence of a solid mass was highly correlated with malignancy with all imaging methods (MDCT; P=0.001, MRCP; P=0.008, EUS; P<0.001, respectively). Presence of thickened irregular walls/septa on MDCT correlated well with malignancy (P=0.019). In contrast, presence of thickened irregular walls/septa on MRCP and intramural nodules on EUS did not correlate with malignancy. No significant correlation was found between malignancy and average maximum MPD diameter or cyst size (P>0.05), though values tended to be larger in malignant tumors. Our results suggest that the presence of thickened irregular walls/septa or a solid mass on MDCT are highly correlated with malignancy, and that MDCT is useful for diagnosis of branch duct IPMNs of the pancreas.