From the Departments of Radiology (M.L.W., J.G.F., A.T.F., J.M.B., J.L.F.) and Gastroenterology (S.L.H., D.H.B.), Mayo Clinic, 200 First St SW, Rochester, MN 55905.
Radiographics. 2018 Jul-Aug;38(4):1089-1107. doi: 10.1148/rg.2018170138. Epub 2018 Jun 8.
Acute gastrointestinal (GI) bleeding is common and necessitates rapid diagnosis and treatment. Bleeding can occur anywhere throughout the GI tract and may be caused by many types of disease. The variety of enteric diseases that cause bleeding and the tendency for bleeding to be intermittent may make it difficult to render a diagnosis. The workup of GI bleeding is frequently prolonged and expensive, with examinations commonly needing to be repeated. The use of computed tomography (CT) for evaluation of acute GI bleeding is gaining popularity because it can be used to rapidly diagnose active bleeding and nonbleeding bowel disease. The CT examinations used to evaluate acute GI bleeding include CT angiography and multiphase CT enterography. Understanding the clinical evaluation of acute GI bleeding, including the advantages and limitations of endoscopic evaluation, is necessary for the appropriate selection of patients who may benefit from CT. Multiphase CT enterography is used primarily to evaluate stable patients who have undergone upper and lower endoscopy without identification of a bleeding source. CT angiography is used to examine stable and unstable patients who respond to resuscitation, are believed to be actively bleeding, and are considered unlikely to have an upper GI source of hemorrhage. In the emergent setting, CT may yield critical information regarding the presence, location, and cause of active bleeding-data that can guide the choice of subsequent therapy. Recent developments in the use of and techniques for performing CT angiography have made it a potential first-line tool for evaluating acute GI bleeding. RSNA, 2018.
急性胃肠道（GI）出血很常见，需要快速诊断和治疗。出血可能发生在胃肠道的任何部位，可能由多种疾病引起。引起出血的肠道疾病种类繁多，且出血具有间歇性，这可能使得诊断变得困难。胃肠道出血的检查过程通常很漫长且昂贵，需要经常重复检查。使用计算机断层扫描（CT）评估急性胃肠道出血越来越受欢迎，因为它可用于快速诊断活动性出血和非出血性肠病。用于评估急性胃肠道出血的 CT 检查包括 CT 血管造影和多期 CT 肠造影。了解急性胃肠道出血的临床评估，包括内镜评估的优缺点，对于适当选择可能从 CT 中受益的患者是必要的。多期 CT 肠造影主要用于评估在上、下内镜检查后未发现出血源的稳定患者。CT 血管造影用于检查稳定和不稳定的患者，这些患者对复苏有反应，被认为有活动性出血，且不太可能有上胃肠道出血源。在紧急情况下，CT 可能提供有关活动性出血的存在、位置和原因的关键信息，这些信息可以指导后续治疗方案的选择。最近在 CT 血管造影的使用和技术方面的进展使其成为评估急性胃肠道出血的潜在一线工具。RSNA，2018 年。
