Describing computed tomography findings in acute necrotizing pancreatitis with the Atlanta classification: an interobserver agreement study.

OBJECTIVES: The 1992 Atlanta classification is a clinically based classification system that defines the severity and complications of acute pancreatitis. A study was undertaken to assess the interobserver agreement of categorizing peripancreatic collections on computed tomography (CT) using the Atlanta classification.
METHODS: Preoperative contrast-enhanced CTs from 70 consecutive patients (49 men; median age, 59 years; range, 29-79 years) operated for acute necrotizing pancreatitis (2000-2003) in 11 hospitals were reviewed. Five abdominal radiologists independently categorized the peripancreatic collections according to the Atlanta classification. Radiologists were aware of the timing of the CT and the clinical condition of the patient. Interobserver agreement was determined.
RESULTS: Interobserver agreement among the radiologists was poor (kappa, 0.144; SD, 0.095). In 3 (4%) of 70 cases, the same Atlanta definition was chosen. In 13 (19%) of 70 cases, 4 radiologists agreed, and in 42 (60%) of 70 cases, 3 radiologists agreed on the definition. In 21 cases (30%), 1 or more of the radiologists classified a collection as "pancreatic abscess," whereas 1 or more radiologist used another Atlanta definition.
CONCLUSION: The interobserver agreement of the Atlanta classification for categorizing peripancreatic collections in acute pancreatitis on CT is poor. The Atlanta classification should not be used to describe complications of acute pancreatitis on CT.