Imaging Spectrum of Duodenal Emergencies

The duodenum, the first portion of the small bowel, is divided into four segments and extends to both retro- and intraperitoneal spaces. Some conditions arise primarily from the duodenum, but it can be secondarily affected by processes that involve neighboring structures. When duodenal emergencies are not identified and treated promptly, they may result in high morbidity and mortality. Imaging plays an important role in the diagnosis of duodenal conditions in the acute setting. However, the radiologic findings can be subtle, and awareness of relevant patient history and clinical presentation is important as it may increase the index of suspicion and one's ability to diagnose these conditions. Duodenal peptic disease is common and can be complicated by bleeding and perforation. The duodenum can be secondarily involved by pancreatitis and gallbladder pathologic conditions and may be affected by iatrogenic complications following endoscopic procedures. Traumatic injuries to the duodenum are generally uncommon, with penetrating traumatic injury being the most frequent mechanism of injury. Duodenal vascular pathologic conditions such as aortoduodenal fistula are uncommon but can be life threatening.The knowledge of which pathologic condition can involve which duodenal segment can help the radiologist establish a differential diagnosis and achieve a more targeted imaging approach. (C) RSNA, 2020