title: Autoimmune pancreatitis and non-necrotizing acute pancreatitis: computed tomography pattern.
abstract: OBJECTIVE
  To retrospectively differentiate diffuse autoimmune pancreatitis from non-necrotizing acute pancreatitis at clinical onset with multi detector row computed tomography.
  
  
  METHODS
  36 Patients suffering from diffuse autoimmune pancreatitis (14) or non-necrotizing acute pancreatitis (22) were enrolled. Qualitative analysis included stranding, retroperitoneal fluid film, capsule-like rim enhancement and pleural effusion. In quantitative analysis pancreatic density was measured in all phases. The vascularization behaviour was assessed using the relative enhancement rate across all phases.
  
  
  RESULTS
  Pancreatic density resulted lower in non-necrotizing acute pancreatitis compared to diffuse autoimmune pancreatitis patients in pre-contrast phase and higher in pancreatic phase. Relative enhancement rate evaluation confirmed different vascularization behaviours of the two diseases. Only non-necrotizing acute pancreatitis Patients presented peripancreatic stranding and fluid in the retromesenteric interfascial plane.
  
  
  CONCLUSIONS
  Multi detector row computed tomography is a useful technique for differentiating diffuse autoimmune pancreatitis from non-necrotizing acute pancreatitis at clinical onset. Peripancreatic stranding and retroperitoneal fluid film, characteristic of non-necrotizing acute pancreatitis, and late-phase peripheral rim enhancement, characteristic of diffuse autoimmune pancreatitis, provide qualitative clues to the differentiation. A quantitative study of contrast enhancement patterns, considering the relative enhancement rate, can assist in the differential diagnoses of two diseases.
authors.affiliation: Department of Radiology, University of Verona, Verona, Italy. rossella.paola.graziani@gmail.com
authors.forename: Rossella
authors.initials: R
authors.lastname: Graziani
authors.forename: Luca
authors.initials: L
authors.lastname: Frulloni
authors.forename: William
authors.initials: W
authors.lastname: Mantovani
authors.forename: Maria Chiara
authors.initials: MC
authors.lastname: Ambrosetti
authors.forename: Simona
authors.initials: S
authors.lastname: Mautone
authors.forename: Thomas Joseph
authors.initials: TJ
authors.lastname: Re
authors.forename: Chiara
authors.initials: C
authors.lastname: Dal Bo
authors.forename: Riccardo
authors.initials: R
authors.lastname: Manfredi
authors.forename: Roberto Pozzi
authors.initials: RP
authors.lastname: Mucelli
mesh_terms: D000273:Adipose Tissue / Q000000981:diagnostic imaging; D000328:Adult; D000368:Aged; D019540:Area Under Curve; D001327:Autoimmune Diseases / Q000000981:diagnostic imaging*; D003287:Contrast Media; D005260:Female; D006801:Humans; D007091:Image Processing, Computer-Assisted; D008297:Male; D008875:Middle Aged; D061330:Multidetector Computed Tomography; D010195:Pancreatitis / Q000000981:diagnostic imaging* / Q000276:immunology; D012372:ROC Curve; D012189:Retrospective Studies
chemical_list: D003287:Contrast Media