MR enterography activity index.
Inflammatory activity in ileocolonic Crohn's disease on MR enterography, from wall thickness, relative contrast enhancement, oedema and ulceration, validated against the CDEIS.
The calculator collects 4 items:
Any item left blank stops the score being calculated — an incomplete form never reports as remission.
| < 7 | Inactive |
| 7 - 10.9 | Active |
| ≥ 11 | Severe lesions |
Bands as implemented in IBD Care. A band is a description of the score, not an instruction.
Requires intravenous gadolinium, which limits repeated use and excludes some patients. It was validated segment by segment against endoscopy, so it reflects inflammation rather than fibrosis, and it does not separate inflammatory from fibrostenotic stricture. A simplified version avoiding contrast exists and its scores are not interchangeable with this one.
Content last reviewed 2026-10-10. References were resolved against PubMed, a service of the US National Library of Medicine, which does not endorse this site.
Magnetic Resonance Index of Activity is implemented as an interactive calculator in IBD Care, with its full guidance and scoring bands.
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