Autoimmune Pancreatitis: MRI pattern including manganese enhancement

Purpose Autoimmune pancreatitis (AIP) is a rare form of chronic pancreatitis based on an autoimmune inflammatory process (1, 2). Up to 5% of all cases of chronic pancreatitis are thought to be AIP (2). It may be focal or diffuse. Typical cross sectional imaging characteristics for AIP include enlargement of the affected parts of the gland, irregular narrowing of the main pancreatic duct and reduced and delayed contrast uptake. To avoid unnecessary surgery focal forms of AIP have to be distinguished from pancreatic adenocarcinoma, while the main differential diagnoses for the diffuse form are pancreatic lymphoma and mild acute pancreatitis. The purpose of this study was to describe MR imaging characteristics of 12 patients with AIP with special emphasis on the value of manganese (MnDPDP, Teslascan) as a pancreas specific contrast agent.