Imaging of Acute Pancreatitis According to the Revised Atlanta Classification

Purpose of Review Accurate detection and characterization of acute pancreatitis plays an increasing importantly role in modern clinical practice. In years past, there has been a lack of standardization in the nomenclature of acute pancreatitis amongst radiologists, leading to ambiguous and often misleading information being conveyed to referring clinicians. Recent Findings In an effort to standardize the nomenclature of acute pancreatitis, the Acute Pancreatitis Classification Working Group was established with the goal of revising the 1992 Atlanta Classification System for acute pancreatitis. The group assembled internationally renowned pancreatic experts with the goal of codifying the descriptive terminology associated with the imaging of acute pancreatitis. Following several revisions, the Revised Atlanta Classification (RAC) system was finalized in 2012. Summary As outlined in the 2012 RAC, acute pancreatitis is now divided into two distinct imaging categories, interstitial edematous pancreatitis and necrotizing pancreatitis, based upon the absence or presence of necrosis, respectively. Additionally, four subtypes were proposed to further characterize the nature and chronicity of pancreatitis-associated fluid collections: acute peripancreatic fluid collections and pseudocysts in the setting of interstitial edematous pancreatitis, and acute necrotic collections and walled-off necrosis in the setting of necrotizing pancreatitis. Generic, non-specific terms such as pancreatic abscess have subsequently fallen out of favor. Implementation of the classification system optimizes communication between radiologists and clinicians in the clinical management of acute pancreatitis and associated complications. This article provides an image-rich overview of various manifestations of acute pancreatitis according to the RAC classification.