Acute pancreatitis is a major cause of hospital admissions in the United States, with the two primary causes being gallstones and alcohol.1 The Atlanta classification system is an international classification on the severity of acute pancreatitis. In 2012, deficiencies and outdated nomenclature were removed to make a revised system that take into account advancements in research and clinical management. The revised Atlanta classification system (RACS) in 2012 standardized the nomenclature for acute pancreatitis and local complications to facilitate effective communication between clinicians and radiologists alike. Older terms such as pancreatic abscess, phlegmon, acute pseudocyst, and fluid collection are no longer used, as they are vague and can be misleading.