Magnetic Resonance Imaging of the Small Bowel in Crohn’s Disease: A Systematic Review and Meta-Analysis

Abstract

Introduction. Crohn's disease is most commonly found in the terminal ileum and colonic region. Magnetic resonance has become a useful modality for assessing small bowel activity. In this study, we performed a systematic review and meta-analysis on the use of MR in detecting small bowel activity as well as extramural complications in Crohn's patients. Methods. Two independent reviewers sorted through articles until October 2, 2014. We included both studies providing raw data for pooling and studies without raw data. Sensitivity, specificity, likelihood ratios, and 95% confidence intervals were calculated for each study. Results. There were 27 included studies, of which 19 were included in the pooled analysis. Pooled analysis of the 19 studies (1020 patients) with raw data revealed a sensitivity of 0.88 (95% CI 0.86 to 0.91) and specificity was 0.88 (95% CI 0.84 to 0.91). In regard to detecting stenosis, pooled sensitivity was 0.65 (95% CI 0.53 to 0.76) and specificity was 0.93 (95% CI 0.89 to 0.96). Conclusion. MR imaging provides a reliable alternative in detecting small bowel activity in patients with Crohn's disease. Its advantages include high diagnostic accuracy and no radiation exposure while its disadvantages include high cost and limited availability.

Diagnostic accuracy of magnetic resonance enterography and small bowel ultrasound for the extent and activity of newly diagnosed and relapsed Crohn's disease (METRIC): a multicentre trial

“…Our detection rates were at the upper end of estimates from previous meta-analyses. 6 , 9 , 10 , 11 , 12 , 13 , 14 , 15 , 16 , 17 , 18 , 19 , 20 Dong and colleagues 12 estimated ultrasound to have a sensitivity 88% and a specificity of 97%; Liu and colleagues 17 reported corresponding figures of 86% sensitivity and 93% specificity for MRE. However, the primary literature is markedly heterogeneous, which affects the validity of point estimates.…”

“…Although meta-analyses 6 , 9 , 10 , 11 , 12 , 13 , 14 , 15 , 16 , 17 , 18 , 19 , 20 suggest that MRE and ultrasound have similar accuracy for diagnosing and staging Crohn's disease, the primary literature is of questionable quality. Most studies 17 , 20 , 21 are small and done in a single centre, and few compare tests directly in the same patients, despite this being advocated as an optimal method for diagnostic accuracy studies.…”

ECCO-ESGAR Guideline for Diagnostic Assessment in IBD Part 1: Initial diagnosis, monitoring of known IBD, detection of complications

“…[246][247][248] A recent meta-analysis of 27 studies [19 included in pooled analysis] showed MRI to have a sensitivity of 0.88 [95% CI 0.86-0.91] and a specificity of 0.88 [95% CI 0.84-0.91]. 249 The studies included both MR with oral contrast solution [MR enterography] or contrast administered by nasojejunal tube insertion [MR enteroclysis]. MRI is perhaps superior to IUS in assessing disease extent 86 and leads to changes in clinical management following investigation 250 ; MRI increases scores of disease location [L] and disease behaviour [B] of the Montreal classification in over 20% of patients.…”

Magnetic resonance enterography compared with ultrasonography in newly diagnosed and relapsing Crohn’s disease patients: the METRIC diagnostic accuracy study

“…There have been several systematic reviews and meta-analyses reporting the accuracy of MRE and US for diagnosing and staging CD. 12,[15][16][17][18][19][20][21][22][23][24][25][26] Many have considered MRE or US in isolation, 15,[17][18][19][20]22,23 whereas others have attempted to compare the two modalities (along with others, such as CT). 12,21,25,26 Some have primarily focused on assessment of disease activity, 17,22,26 with most assessing diagnostic accuracy.…”