Intraductal papillary tumors of the pancreas: evaluation with magnetic resonance cholangiopancreatography

Abstract

Objective: We analyzed the findings of intraductal papillary tumors of the pancreas by magnetic resonance cholangiopancreatography (MRCP).

Methods: Twelve patients with intraductal papillary tumors (main duct type, n = 3; branch duct type, n = 8; combined type, n = 1) underwent endoscopic retrograde cholangiopancreatography (ERCP) (n = 11) and MRCP, using half-Fourier acquisition single-shot turbo spin-echo (HASTE) sequences (n = 12). Imaging findings were compared with operative and pathological findings in all the patients.

Results: Although ERCP failed to fully depict the main pancreatic duct and cystic tumors in six of 11 patients because of copious intraductal mucin, MRCP provided complete images of these structures in all 12 patients. In main duct type tumors, MRCP demonstrated moderate-marked, diffuse dilation of the main pancreatic duct. Branch duct type tumors showed "grape-like" clusters of cysts with no or only mild, diffuse dilation of the main duct. In combined type tumors, MRCP demonstrated a markedly dilated main duct with a large unilocular cyst of the collateral duct. MRCP detected more mural nodules (75%, three of four patients) than ERCP (25%, one of four). MRCP allowed more precise diagnosis of the type, size, and extent of tumors than ERCP, as confirmed by pathologic findings.

Conclusion: MRCP demonstrates intraductal papillary tumors less invasively and more completely than ERCP.