Comparison of Magnetic Resonance Imaging and Endoscopic Ultrasound in the Sizing of Intraductal Papillary Mucinous Neoplasia of the Pancreas

Objectives: Because IPMNs are potentially malignant, surveillance of IPMN is recommended by magnetic resonance imaging (MRI) and endoscopic ultrasound (EUS). The aim of the study was the evaluation of the concordance between EUS and MRI regarding cyst size.Methods: Retrospective data analysis was done for patients with IPMN in whom EUS and MRI were performed simultaneously (<= 60 days). The measured cyst size of both procedures was compared by Bland-Altman plots. Agreement of cyst localization and dilation of main pancreatic duct was assessed using kappa statistics.Results: Fifty-nine cases were evaluated (median age, 71 years; 65% female; median time interval between both investigations, 17 days). The mean difference of IPMN maximal diameter between EUS and MRI was 0.55 mm with a prediction interval of -9.20 to +10.29 mm for 95% of the expected differences. There was strong interobserver agreement regarding cyst localization ( kappa = 0.669, P = 1.06e -13 ) and the width of main pancreatic duct (<5, 5-9, and >= 10 mm; kappa = 0.676 caput, kappa = 0.823 corpus).Conclusions: We found a clinically relevant difference in cyst size comparing EUS and MRI. Therefore, alternating EUS and MRI for follow-up of the "worrisome feature" size growth is not reasonable.