The role of imaging in gastrointestinal bleed

Abstract

Gastrointestinal (GI) bleed accounts for approximately 20% of emergency visits; 2% of hospital admissions and its incidence has been increasing. In patients where the GI bleed does not stop spontaneously, intervention is required to identify the source of bleeding and stop the hemorrhage. Although identifying the source of bleeding can be challenging due to the vast number of underlying etiologies, radiology plays a vital role in patients where endoscopy and/or medical management fail. Radiology offers both non-invasive and invasive options for the diagnosis as well as management of GI bleeds. Scintigraphy and computed tomography angiography (CTA) are the most important non-invasive imaging tests that can identify presence of and help locate the site of bleeding and are used when the patient is hemodynamically stable. If the patient is hemodynamically unstable, conventional angiography (CA) allows diagnosis of the presence, site of bleeding as well as the means of treating the bleed by embolization. Our review article focuses on the various etiologies of GI bleed, the role of imaging in diagnosis as well as treatment of these patients based on the underlying etiologies, the merits and disadvantages of each of these modalities with emphasis on triaging patients for the most appropriate imaging test to guide the most suitable management.

Keywords: Gastrointestinal bleeding; computed tomography angiography (CTA); conventional angiography (CA); scintigraphy.

Figure 1

A 70-year-old male presenting with bleeding per rectum and drop in hematocrit. Colonoscopy was negative; underwent tagged RBC scan that demonstrated site of active bleeding in the hepatic flexure of the colon (A, arrow) which was subsequently embolized via conventional angiography (B, C: arrowheads).

Figure 2

A 56-year-old male presenting with upper GI bleeding was found to have a friable mass in the gastric fundus on upper endoscopy (A, arrow). He presented with re-bleed a few months later when CT angiogram demonstrated ongoing active bleed from the mass (B, C: coronal CTA images—arrowheads). The mass was then surgically removed, proven to be a gastrointestinal stromal tumor.

Figure 3

A 72-year-old male presenting with anemia and no active demonstrable source of bleeding on upper or lower endoscopy. CT enterography demonstrated multiple dilated vessels in the wall of the jejunum (A: axial CTE image; B: coronal CTE image; C: sagittal CTE image) on the enteric phase (arrows) which were also demonstrated on the subsequently performed capsule endoscopy compatible with jejunal vascular malformations, presumed to be the cause for occult GI bleed.

Figure 4

A 69-year-old male presenting with hematemesis was found to have active bleeding from a posterior duodenal ulcer on upper endoscopy (A, arrow). It was then interrogated by conventional angiography and active bleeding was identified from branches of the gastroduodenal artery (B, arrowhead) that was then successfully coil embolized (C, arrowhead).

Figure 5

A 72-year-old female presenting with bright red blood per rectum was found to have an active bleed from sigmoid colonic diverticula (A, B: arrows). Catheter angiography with superselective interrogation of the left sided inferior mesenteric arterial branches (C, arrowhead) demonstrated the site of active bleed (arrowheads) with successful coil embolization (D, arrowhead) to stop the bleeding.