title: Paraduodenal pancreatitis: clinical performance of MR imaging in distinguishing from carcinoma.
abstract: OBJECTIVE
  To evaluate the diagnostic performance of contrast material-enhanced magnetic resonance (MR) imaging for distinguishing paraduodenal pancreatitis (PDP) from pancreatic head duct adenocarcinoma (CA) in patients with diagnoses confirmed by histopathologic analysis.
  
  
  METHODS
  This retrospective study was approved by the institutional review board and is HIPAA compliant. Between July 2007 and July 2010, 47 patients who underwent Whipple procedure and MR imaging less than 60 days before surgery were identified retrospectively. Two relatively inexperienced fellowship trainees with 9 months of body fellowship training were asked to record the presence or absence of three MR imaging features: focal thickening of the second portion of the duodenum; abnormal enhancement of the second portion of the duodenum; and cystic focus in the expected region of the accessory pancreatic duct. Strict criteria for diagnosis of PDP included presence of all three imaging features. Any case that did not fulfill the criteria was classified as CA. Sensitivity, specificity, positive predictive value, and negative predictive value for characterization of PDP was calculated for each reader with 95% confidence intervals. A κ test assessed level of agreement between readers.
  
  
  RESULTS
  Each reader correctly categorized 15 of 17 (88.2%) PDP cases when all three imaging criteria were met. Alternatively, 26 of 30 (86.7%) pancreatic duct CA were correctly categorized as inconsistent with PDP. Four patients with histopathologic diagnosis of CA were incorrectly classified as PDP by each reader. Agreement between the two readers showed substantial κ agreement for the diagnosis of PDP and differentiation from pancreatic duct CA.
  
  
  CONCLUSIONS
  Contrast-enhanced MR imaging may help accurately identify PDP and distinguish it from CA when strict diagnostic criteria are followed.
  
  
  BACKGROUND
  http://radiology.rsna.org/lookup/suppl/doi:10.1148/radiol.13112056/-/DC1.
authors.affiliation: Department of Radiology, University of Arizona College of Medicine, 1501 N Campbell Ave, Tucson, AZ 85724; Departments of Surgery and Pathology, Emory University School of Medicine, Atlanta, Ga; Department of Radiology, University of Virginia School of Medicine, Charlottesville, Va; Rome Radiology Group, Rome, Ga; Department of Medicine, Beth Israel Deaconess Medical Center, Boston, Mass.
authors.forename: Bobby
authors.initials: B
authors.lastname: Kalb
authors.forename: Diego R
authors.initials: DR
authors.lastname: Martin
authors.forename: Juan M
authors.initials: JM
authors.lastname: Sarmiento
authors.forename: Sarah H
authors.initials: SH
authors.lastname: Erickson
authors.forename: Daniel
authors.initials: D
authors.lastname: Gober
authors.forename: Elliot B
authors.initials: EB
authors.lastname: Tapper
authors.forename: Zhengjia
authors.initials: Z
authors.lastname: Chen
authors.forename: N Volkan
authors.initials: NV
authors.lastname: Adsay
mesh_terms: D000230:Adenocarcinoma / Q000175:diagnosis; D000368:Aged; D021441:Carcinoma, Pancreatic Ductal / Q000175:diagnosis; D003287:Contrast Media; D003937:Diagnosis, Differential; D004378:Duodenal Diseases / Q000175:diagnosis* / Q000601:surgery; D005260:Female; D006801:Humans; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D008536:Meglumine / Q000031:analogs & derivatives; D008875:Middle Aged; D009942:Organometallic Compounds; D010190:Pancreatic Neoplasms / Q000175:diagnosis; D010195:Pancreatitis / Q000175:diagnosis* / Q000601:surgery; D011237:Predictive Value of Tests; D012189:Retrospective Studies; D012680:Sensitivity and Specificity
chemical_list: D003287:Contrast Media; D009942:Organometallic Compounds; C064572:gadobenic acid; D008536:Meglumine