Fluoroscopic Evaluation of Duodenal Diseases.

The duodenum can be affected by a variety of abnormalities because of its development during embryogenesis and its dual intra- and retroperitoneal location. If small bowel embryogenesis is disturbed, congenital errors occur. Although some congenital variants may be asymptomatic and inconsequential to the patient, other anomalies can result in life-threatening emergencies such as malrotation, leading to midgut volvulus. Many infectious processes affect the duodenum, including duodenal ulcers and opportunistic infection in patients with HIV/AIDS or Crohn disease. Small bowel malignancies are uncommon but important to recognize, because the duodenum can be involved in polyposis syndromes or the development of primary adenocarcinoma, neuroendocrine tumors, lymphoma, and metastasis. Although endoscopy is currently the most used diagnostic method to assess the lumen of the upper gastrointestinal tract, fluoroscopy is a valuable adjunct technique and the study of choice for many diseases, specifically those for which anatomic and functional information is required. Fluoroscopy is also commonly used postoperatively to assess for complications such as obstruction and extraluminal leaks. Compared with endoscopy, fluoroscopy is an inexpensive and noninvasive technique that provides salient anatomic information and allows delineation of the duodenal mucosa and assessment of real-time duodenal motility. The authors examine the broad spectrum of conditions that can involve the duodenum, including congenital, infectious, inflammatory, and neoplastic abnormalities, and review their typical appearances at fluoroscopy. RSNA, 2022.