CT enterography in obscure gastrointestinal bleeding: A systematic review and meta‐analysis

Abstract

The objective of this article is to provide a comprehensive and update overview of clinical application of CT enterography (CTE) in the evaluation of obscure gastrointestinal bleeding (OGIB). We performed a systematic review of relevant literatures in PubMed, EMBASE and The Cochrane Library and pooled the yield of CTE and the incremental yield (IY) of CTE over an alternate modality. A total of 18 studies (n = 660) reported the yield of CTE in evaluating OGIB and the pooled yield was 40% (95% confidence interval (CI): 33-49%). Seven studies (n = 279) compared the yield of CTE with capsule endoscopy (CE). The yield for CTE and CE for all findings was 34% and 53%, respectively (IY = -19%, 95% CI = -34% to -4%). When considering the types of identified lesions, the yield was significantly different for vascular and inflammatory lesions but not significantly different for neoplastic or other lesions. Two studies (n = 63) compared the yield of CTE with double-balloon enteroscopy (DBE). The yield for CTE and DBE was 38% and 78%, respectively (IY = -40%, 95% CI = -55% to -25%). Three studies (n = 49) compared the yield of CTE with digital subtraction angiography. The yield for CTE and digital subtraction angiography was 64% and 60%, respectively (IY = 4%, 95% CI = -40% to 47%). CTE is an excellent diagnostic tool in patients with OGIB. It may play a complementary role to CE and can be used as a triage tool prior to DBE in evaluating OGIB.

Gastrointestinal hemorrhage: evaluation with MDCT

“…Limitations include radiation exposure for multi-phasic examinations [51], the need for IV contrast, and learning curve to allow detection of subtle vascular abnormalities. In a meta-analysis of 18 studies, CTE had a pooled yield of 40% compared to 53% for capsule endoscopy [48]. Other studies have shown similar yields for CTE [22,[55][56][57].…”

“…Capsule endoscopy has been shown to have excellent detection rates of vascular and inflammatory lesions, with superior yields compared to barium and cross-sectional imaging techniques [45,48,49]. Limitations include the risk of capsule retention [50], up to 30% rate of false-positive exams [46], up to 20-25% rate of incomplete small bowel examination [46,48], and difficulty in detecting small bowel masses, especially mural-based lesions [50][51][52][53]. In a study by Huprich et al, CT enterography (CTE) detected 9 of 9 small bowel tumors compared to 3 of 9 for capsule endoscopy [51].…”

“…Several studies have shown that capsule endoscopy has higher yields for detecting vascular and inflammatory lesions than CTE [45,48,49]. However, CTE can detect vascular and inflammatory abnormalities which may be missed on capsule endoscopy [51].…”

Small Bowel Capsule Endoscopy

“…small bowel follow through. Although most radiological methods provide-just like CE-views of the entire small bowel, they are 'betrayed' by their low spatial resolution in cases of small, superficial lesions such as vascular malformations, erosions or ulcers [46,47].…”

CT enterography for Crohn’s disease: optimal technique and imaging issues

“…In order to achieve a high level of efficacy, optimal technique is critical, especially in evaluating patients with obscure gastrointestinal bleeding [6][7][8][9][10][11][12][13][14][15][16][17][18][19][20][21][22]. Further, because CT is now the greatest, single source of nonbackground ionizing radiation in the United States [23] (exposure from medical sources of ionizing radiation in 2006 accounted for 48% of the total exposure as opposed to 50% from background; CT contributes 49% of the medical exposure), dose reduction techniques should be utilized, especially in Crohn's patients, given the chronicity of their disease and the likelihood that they will have repeated examinations in their lifetime.…”