Describing peripancreatic collections in severe acute pancreatitis using morphologic terms: an international interobserver agreement study

Abstract

Background/aims: The current terminology for describing peripancreatic collections in acute pancreatitis (AP) derived from the Atlanta Symposium (e.g. pseudocyst, pancreatic abscess) has shown a very poor interobserver agreement, creating the potential for patient mismanagement. A study was undertaken to determine the interobserver agreement for a new set of morphologic terms to describe peripancreatic collections in AP.

Methods: An international, interobserver agreement study was performed: 7 gastrointestinal surgeons, 2 gastroenterologists and 8 radiologists in 3 US and 5 European tertiary referral hospitals independently evaluated 55 computed tomography (CT) scans of patients with predicted severe AP. The percentage agreement [median, interquartile range (IQR)] for 9 clinically relevant morphologic terms was calculated among all reviewers, and separately among radiologists and clinicians. The percentage agreement was defined as poor (<0.50), moderate (0.51-0.70), good (0.71-0.90), and excellent (0.91-1.00).

Results: Overall agreement was good to excellent for the terms collection (percentage agreement = 1; IQR 0.68-1), relation with pancreas (1; 0.68-1), content (0.88; 0.87-1), shape (1; 0.78-1), mass effect (0.78; 0.62-1), loculated gas bubbles (1; 1-1), and air-fluid levels (1; 1-1). Overall agreement was moderate for extent of pancreatic nonenhancement (0.60; 0.46-0.88) and encapsulation (0.56; 0.48-0.69). The percentage agreement was greater among radiologists than clinicians for extent of pancreatic nonenhancement (0.75 vs. 0.57, p = 0.008), encapsulation (0.67 vs. 0.46, p = 0.001), and content (1 vs. 0.78, p = 0.008).

Conclusion: Interobserver agreement for the new set of morphologic terms to describe peripancreatic collections in AP is good to excellent. Therefore, we recommend that current clinically based definitions for CT findings in AP (e.g. pancreatic abscess) should no longer be used.