Extrapancreaticimagingfindingsofautoimmunepancreatitis

Objective Todescribetheimagingfindingsofextrapancreaticlesionsof autoimmunepancreatitis (AIP). Methods FromMay,2004toJune,2012,44patientswerediagnosed ofAIPaccordingtoAsiacriteriaofAIPmadein2008.Alltheimagingdata,includingcontrastenhancedCT (in29patients) or/andMR (in38patients),and18F-FDGPET-CT (in6patients),were retrospectivelyreviewed.Alltheextrapancreaticlesionswasdescribedinvolvedinbileduct,gallbladder,kidneys,vessels,lymphnodes,liver,digestivetract,retroperitoneum,andsalivaryglands,etc. Results IgG4-relatedsclerosingcholangitiswasrevealedin32patients,presentedbiliary stricturesandthickenedwallofbileducts.Amongthose,biliarylesionsinvolvedintrapancreatic segmentofcommonbileduct (CBD) in16patients,hilarbileductin1patient,bothintrapancreatic andextrapancreaticsegmentofCBDin15patients,separately.NineteenpatientswithAIPpresented dilatedgallbladder,withdelayedenhancementofthethickenedwall.Renalinvolvementwasobservedin 10,patientsappearedasmultipleroundorwedge-shapedlow-enhancedfociinbilateralrenal parenchyma,whichwerehypo-intenseonT2-weightedimageswithmildenhancement.Bloodvessel involvementwasobservedin16patients,appearedasembeddedvesselswithorwithout stenosis.Furthermore,abdominallymphadenopathywasobservedin35patients,inwhichceliaclymph nodegroupwascommonlyfoundinadditiontotheinvolvementofmultiplelymphnodegroupsfor15 patients.Twopatientspresenteddelayedenhancementofserosaofstomachandproximal intestine.Threepatientswerediagnosedtohaveretroperitonealfibrosissurroundingtheaorta,inferior mesentaryarteryandsuperiormesentaryartery.Focalnodularandabnormalenhancementofpatchy lesion around intrahepatic bile duct implied of liver involvements in 2 patients.Five among six patients who took18F-FDG PET-CT were observed salivary involvements with pathologic uptake of18FFDG. Conclusion As multiple organs involvement was the critical characterization of AIP,sufficient understanding of relevant extrapancreatic diseases would be helpful to the diagnosis of this disease. Key words: Pancreatitis; Tomography,X-ray computed; Magnetic resonance imaging; Positron-emission tomography