Imaging diagnosis of autoimmune pancreatitis: computed tomography and magnetic resonance imaging

Autoimmune pancreatitis (AIP) is a pancreatic phenotype of IgG4-related systemic disease. Since its first description in the literature, characteristic imaging features have gradually become known to many clinicians encompassing various specialties in the past quarter century. CT and MRI have been the workhorses for imaging diagnosis of AIP. Typical features include sausage-like swelling of the focal or entire pancreas, duct-penetrating sign, a capsule-like rim of the affected lesions, and homogeneous delayed enhancement or enhanced duct sign after contrast administration, as well as characteristic combined findings reflecting coexisting pathologies in the other organs as a systemic disease. In this review, recent and future developments in CT and MRI that may help diagnose AIP are discussed, including restricted diffusion and perfusion and increased elasticity measured using MR.

Automated summary

Autoimmune pancreatitis (AIP) is a pancreatic manifestation of IgG4-related systemic disease, characterized by specific imaging features such as pancreatic swelling, duct-penetrating sign, capsule-like rim, enhanced duct sign after contrast administration, and combined findings reflecting coexisting pathologies in other organs. Recent and future developments in CT and MRI, including restricted diffusion, perfusion, and increased elasticity measurements using MR, may aid in diagnosing AIP.