The revised Atlanta classification for acute pancreatitis: updates in imaging terminology and guidelines

Imaging of acute pancreatitis requires not only an understanding of the disease subtypes and the myriad of associated complications but also familiarity with the appropriate radiologic nomenclature as defined by the Atlanta symposium in 1992 and, more recently, by the Acute Pancreatitis Classification Working Group in 2008. The accurate description of the radiological findings plays a critical role in the evaluation and management of patients with acute pancreatitis, particularly those with severe disease. There have been increasing efforts to develop uniformity in the use of terminology used to define the radiologic findings in acute pancreatitis, in particular, the terminology for fluid collections, a common area of inconsistency and confusion. Terms such as "acute peripancreatic fluid collections," "acute post- necrotic fluid collections," "pseudocyst," and "walled-off pancreatic necrosis" are now recommended as they describe the evolution of fluid collections in patients with both interstitial and necrotizing pancreatitis and nonspecific terms such as "pancreatic abscess" and "phlegmon" are being abandoned. In this review we illustrate, with case examples, the standardized terminology used in the radiological and clinical description of acute pancreatitis, its severity, and complications with an emphasis on the role of ultrasound, computed tomography and magnetic resonance imaging. Different management options of the associated complications are also discussed. The use of standardized terminology will hopefully improve the communication between radiologists, gastroenterologists, and surgeons to facilitate treatment planning and will lead to enhanced outcomes for patients with acute pancreatitis as well as create uniformity for enrollment into research studies.