Systematic review with meta‐analysis: magnetic resonance enterography vs. computed tomography enterography for evaluating disease activity in small bowel Crohn's disease

Summary Background Magnetic resonance enterography ( MRE ) has been proposed as a non‐ionising alternative method to computed tomography enterography ( CTE ). Some studies have directly compared CTE and MRE in patients with small bowel Crohn's disease ( CD ) with variable results. Aim To compare the overall diagnostic accuracy in assessing the activity of small bowel and complications. Methods MEDLINE , EMBASE and Cochrane databases were searched for studies on the accuracy of MRE and CTE , as compared with a pre‐defined reference standard. Pooled sensitivity, specificity, the weighted area under the curve ( AUC ), incremental yield ( IY ) and other diagnostic indices were evaluated. Results A total of 290 CD patients from six different studies were analysed. The pooled sensitivity and specificity for MRE in detecting active small bowel CD was 87.9% [95% confidence interval ( CI ), 81.8–92.5] and 81.2% (95% CI : 71.9–88.4) respectively. The AUC under the summary receiver‐operating characteristic (s ROC ) of MRE was 0.905 (SEM 0.03, standard error of the mean). Likewise, the pooled sensitivity and specificity of CTE in detecting active small bowel CD was 85.8% (95% CI : 79.2–90.9) and 83.6% (95% CI : 75.3–90.1) with the AUC of 0.898. The AUC of MRE in detecting fistula, stenosis and abscess was 0.936, 0.931 and 0.996, respectively, compared to 0.963, 0.616 and 0.899 of CTE . No statistically significant IY for MRE vs. CTE was found (fixed model, P  >   0.05). Conclusions Magnetic resonance enterography has a diagnostic effectiveness comparable to computed tomography enterography, thus may serve as a radiation‐free alternative for evaluation of patients with Crohn's disease.