title: Significant inter-observer variation in the diagnosis of extrapancreatic necrosis and type of pancreatic collections in acute pancreatitis - An international multicenter evaluation of the revised Atlanta classification.
abstract: BACKGROUND
  For consistent reporting and better comparison of data in research the revised Atlanta classification (RAC) proposes new computed tomography (CT) criteria to describe the morphology of acute pancreatitis (AP). The aim of this study was to analyse the interobserver agreement among radiologists in evaluating CT morphology by using the new RAC criteria in patients with AP.
  
  
  METHODS
  Patients with a first episode of AP who obtained a CT were identified and consecutively enrolled at six European centres backwards from January 2013 to January 2012. A local radiologist at each center and a central expert radiologist scored the CTs separately using the RAC criteria. Center dependent and independent interobserver agreement was determined using Kappa statistics.
  
  
  RESULTS
  In total, 285 patients with 388 CTs were included. For most CT criteria, interobserver agreement was moderate to substantial. In four categories, the center independent kappa values were fair: extrapancreatic necrosis (EXPN) (0.326), type of pancreatitis (0.370), characteristics of collections (0.408), and appropriate term of collections (0.356). The fair kappa values relate to discrepancies in the identification of extrapancreatic necrotic material. The local radiologists diagnosed EXPN (33% versus 59%, P < 0.0001) and non-homogeneous collections (35% versus 66%, P < 0.0001) significantly less frequent than the central expert. Cases read by the central expert showed superior correlation with clinical outcome.
  
  
  CONCLUSIONS
  Diagnosis of EXPN and recognition of non-homogeneous collections show only fair agreement potentially resulting in inconsistent reporting of morphologic findings.
authors: Department of Surgery, Institution of Clinical Sciences Malmö, Lund University, Malmö, Sweden. Electronic address: Hanna.Sternby@med.lu.se.
authors: Hanna
authors: H
authors: Sternby
authors: Department of Gastroenterology, St. Antonius Hospital, Nieuwegein, The Netherlands.
authors: Robert C
authors: RC
authors: Verdonk
authors: Department of Radiology, Hospital del Mar, Barcelona, Spain.
authors: Guadalupe
authors: G
authors: Aguilar
authors: Department of Surgery, University Hospital for Emergency Medicine "Pirogov", Sofia, Bulgaria.
authors: Alexandra
authors: A
authors: Dimova
authors: Department of Surgery, Lithuanian University of Health Sciences, Kaunas, Lithuania.
authors: Povilas
authors: P
authors: Ignatavicius
authors: Department of Gastroenterology, Hospital del Mar, Barcelona, Spain.
authors: Lucas
authors: L
authors: Ilzarbe
authors: Department of Gastroenterology, East Tallinn Central Hospital, Tallinn, Estonia.
authors: Peeter
authors: P
authors: Koiva
authors: Department of Radiology, Helsinki University Central Hospital, Helsinki, Finland.
authors: Eila
authors: E
authors: Lantto
authors: Department of Radiology, East Tallinn Central Hospital, Tallinn, Estonia.
authors: Tonis
authors: T
authors: Loigom
authors: Department of Surgery, Helsinki University Central Hospital, Helsinki, Finland.
authors: Anne
authors: A
authors: Penttilä
authors: Department of Surgery, Institution of Clinical Sciences Malmö, Lund University, Malmö, Sweden.
authors: Sara
authors: S
authors: Regnér
authors: Department of Internal Medicine, Neurology and Dermatology, Division of Gastroenterology and Rheumatology, Leipzig, Germany.
authors: Jonas
authors: J
authors: Rosendahl
authors: Department of Emergency Radiology, University Hospital for Emergency Medicine "Pigorov", Sofia, Bulgaria.
authors: Vanya
authors: V
authors: Strahinova
authors: Department of Radiology, Institution of Clinical Sciences Malmö, Lund University, Malmö, Sweden.
authors: Sophia
authors: S
authors: Zackrisson
authors: Department of Radiology, Lithuanian University of Health Sciences, Kaunas, Lithuania.
authors: Kristina
authors: K
authors: Zviniene
authors: Department of Radiology, St. Antonius Hospital, Nieuwegein, The Netherlands.
authors: Thomas L
authors: TL
authors: Bollen
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002097:C-Reactive Protein / Q000032:analysis; D003627:Data Interpretation, Statistical; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009102:Multiple Organ Failure / Q000209:etiology / Q000401:mortality; D009336:Necrosis; D015588:Observer Variation; D019283:Pancreatitis, Acute Necrotizing / Q000145:classification* / Q000175:diagnosis* / Q000000981:diagnostic imaging; D018746:Systemic Inflammatory Response Syndrome / Q000209:etiology / Q000401:mortality; D014057:Tomography, X-Ray Computed; D055815:Young Adult
chemical_list: D002097:C-Reactive Protein
keywords: Acute pancreatitis; Classification; Computed tomography; Extrapancreatic necrosis; Necrotising pancreatitis