Multi-detector CT: review of its use in acute GI haemorrhage.

The advent of multi-section computed tomography (CT) technology allows the non-invasive assessment of the arterial tree. Using current software, it is now possible to produce high-quality, angiographic-like images that can be used to plan and guide therapeutic procedures. One such clinical situation is the assessment of patients with acute gastrointestinal (GI) haemorrhage. Multi-section CT has a number of advantages over conventional angiography in this situation. The simplicity and non-invasive nature of the technique compared with conventional angiography make CT angiography possible in situations where conventional angiography is not available. Movement artefact from respiration and peristalsis is a common problem in the interpretation of conventional angiography; this is essentially abolished with rapid acquisition times and the use of multi-planar images to remove overlying bowel loops. Cross-sectional imaging with the ability for multi-planar reconstruction allows the accurate anatomical localization of the bleeding site, as well as an assessment of the underlying pathology: this can be used to plan therapy (embolization or surgery). The aim of this paper is to review the current use of CT in the investigation of patients with GI haemorrhage, illustrated with images from our Institution. For patients in whom GI endoscopy has failed to establish a diagnosis, we propose multi-section CT angiography as the initial imaging investigation in acute GI haemorrhage.