Diagnostic Accuracy of Capsule Endoscopy for Small Bowel Crohn's Disease Is Superior to That of MR Enterography or CT Enterography

Abstract

Capsule endoscopy (CE) detects small bowel Crohn's disease with greater diagnostic yield than radiologic procedures, although there are concerns that CE has low specificity. We compared the sensitivity and specificity of CE, magnetic resonance imaging enterography (MRE) and computed tomography enterography (CTE) in patients with suspected or newly diagnosed Crohn's disease. We performed a prospective, blinded study of 93 patients scheduled to undergo ileocolonoscopy, MRE, and CTE and subsequently CE if stenosis was excluded. Physicians reporting CE, MRE, and CTE results were blinded to patient histories and findings from ileocolonoscopy and other small bowel examinations. Results were compared with those from ileoscopy (n = 70), ileoscopy and surgery (n = 4), or surgery (n = 1). Twenty-one patients had Crohn's disease in the terminal ileum. The sensitivity and specificity for diagnosis of Crohn's disease of the terminal ileum were 100% and 91% by CE, 81% and 86% by MRE, and 76% and 85% by CTE, respectively. Proximal Crohn's disease was detected in 18 patients by using CE, compared with 2 and 6 patients by using MRE or CTE, respectively (P < .05). Small bowel stenosis was observed in 5 patients by using CTE and 1 patient by using MRE. Cross-sectional imaging results indicated additional stenoses in only 2 of the patients who received complete ileocolonoscopies. In suspected or newly diagnosed Crohn's disease, MRE and CTE have comparable sensitivities and specificities. In patients without endoscopic or clinical suspicion of stenosis, CE should be the first line modality for detection of small bowel Crohn's disease beyond the reach of the colonoscope.