Acute necrotizing pancreatitis is a severe form of acute pancreatitis characterized by necrosis in and around the pancreas and is associated with high rates of morbidity and mortality. Although acute interstitial edematous pancreatitis is diagnosed primarily on the basis of signs, symptoms, and laboratory test findings, the diagnosis and severity assessment of acute necrotizing pancreatitis are based in large part on imaging findings. On the basis of the revised Atlanta classification system of 2012, necrotizing pancreatitis is subdivided anatomically into parenchymal, peripancreatic, and combined subtypes, and temporally into clinical early (within 1 week of onset) and late (>1 week after onset) phases. Associated collections are categorized as "acute necrotic" or "walled off" and can be sterile or infected. Imaging, primarily computed tomography and magnetic resonance imaging, plays an essential role in the diagnosis of necrotizing pancreatitis and the identification of complications, including infection, bowel and biliary obstruction, hemorrhage, pseudoaneurysm formation, and venous thrombosis. Imaging is also used to help triage patients and guide both temporizing and definitive management. A "step-up" method for the management of necrotizing pancreatitis that makes use of imaging-guided percutaneous catheter drainage of fluid collections prior to endoscopic or surgical necrosectomy has been shown to improve clinical outcomes. The authors present an algorithmic approach to the care of patients with necrotizing pancreatitis and review the use of imaging and interventional techniques in the diagnosis and management of this pathologic condition.

Given the rarity of this disease process and lack of pathognomonic imaging findings, a definitive diagnosis based solely on imaging findings alone is untenable. Select cases are used to emphasize the particularly infiltrative and aggressive nature of NUT midline carcinoma, which shows a complete disregard for normal tissue boundaries and rapid progression during brief intervals.

Disease Epidemiology Esophageal injuries are classified into two broad subcategories: iatrogenic and noniatrogenic. Iatrogenic injuries represent more than half of all cases and have been reported to represent as many as 59% of cases, with endoscopic injury being the most common cause [1]. Although the relative incidence of esophageal injury during endoscopy is low (< 0.04%), because of its overall prevalence, it represents the most common cause of iatrogenic esophageal injury [2]. Noniatrogenic esophageal injuries are most commonly spontaneous perforations occurring after foreign body ingestion (15% of cases), food impaction or vomiting (12% of cases), and trauma (9% of cases) [1]. The average mortality rate is 19% for iatrogenic esophageal injury, compared with 36% for noniatrogenic causes. This difference in mortality results from the subacute nature of many noniatrogenic injuries leading to a delay in diagnosis and treatment [3]. Pathophysiologic Basis: Anatomy and Predisposition to Injury The esophagus is located in the prevertebral mediastinum and is subdivided into four anatomic regions: cervical, thoracic, lower thoracic-esophageal junction, and abdominal (Table 1). A number of factors predispose the esophagus to injury, including its close approximation to extrinsic structures at the level of the cricopharyngeal muscle, left mainstream bronchus, aortic arch, and diaphragmatic hiatus [4]. In addition, its location in close proximity to cervical and intrathoracic organs, including the thyroid, trachea, aorta, and spine, place the esophagus at increased risk secondary to disease processes and surgeries involving these adjacent organs. Beyond anatomic considerations, the esophagus has a relatively poor vascular supply, heightening the probabili