Analysis by AJ. Aschoff, T. Jäckle
Acute gastrointestinal (GI) bleeding is an emergency situation with mortality rates of 8%-14% (1). Mortality rates are higher in elderly persons, in patients with severe comorbidity, and in those with rebleeding (2). Depending on the site of bleeding (proximal or distal of the ligament of Treitz), GI hemorrhage can be divided into bleeding of the upper or lower GI tract. Annual incidence for GI bleeding ranges between 20 and 150 cases per 100 000 persons, with a higher incidence for upper GI hemorrhage (3).
Fast detection and localization of the bleeding site is extremely important. Currently, the first diagnostic procedure in cases of suspected upper GI tract bleeding is endoscopy, whereas for lower GI tract hemorrhage patients undergo colonoscopy, conventional angiography or 99mTc-red blood cell scintigraphy. These procedures have some limitations. In unprepared endoscopy, the bleeding site may be obscured by blood clots or feces. Conventional angiography is an invasive technique carrying a risk of complications (3). Finally, scintigraphy is a time-consuming method with a limited ability to identify bleeding sites.
Due to higher spatial and temporal resolution provided by newer generation MDCT technology, acquisition of arterial- and portal-venous phase images as well as depiction of active extravasation of contrast medium have become feasible. Several studies have evaluated the usefulness of MDCT in localizing GI bleeding restricted to the lower GI tract (5 – 8), and two recent studies assessed the role of MDCT in detecting bleeding sources in the upper and lower GI tracts (9 – 11).