Non-perforating small bowel Crohn's disease assessed by MRI enterography: derivation and histopathological validation of an MR-based activity index

Eur J Radiol. 2012 Sep;81(9):2080-8. doi: 10.1016/j.ejrad.2011.07.013. Epub 2011 Sep 15.


Objectives: To develop and validate a qualitative scoring system for enteric Crohn's disease activity using MR enterography (MRE).

Methods: MRE was performed in 16 patients (mean age 33, 8 male) undergoing small bowel resection. Mural thickness, T2 signal, contrast enhancement, and perimural oedema were scored qualitatively (0-3) at 44 locations. Transmural histopathological scoring of acute inflammation (AIS) was performed at all locations (score 0-13). MRI parameters best predicting AIS were derived using multivariate analysis. The MRI activity index was applied to 26 Crohn's patients (mean age 32, range 13-69 years, 15 male) and correlated to terminal ileal biopsy scores of acute inflammation ("eAIS" score 1-6). Receiver operator characteristic curves were calculated.

Results: Mural thickness (coefficient 1.34 (95% CI 0.36, 2.32)], p=0.007) and T2 signal (coefficient 0.90 (95% CI -0.24, 2.04) p=0.06) best predicted AIS (AIS=1.79+1.34*mural thickness+0.94*mural T2 score [R-squared 0.52]). There was a significant correlation between the MRI index and eAIS (Kendall's tau=0.40, 95% CI 0.11-0.64, p=0.02). The model achieved a sensitivity of 0.81 (95% CI 0.54-0.96), specificity of 0.70 (0.35-0.93) and AUC 0.77 for predicting acute inflammation (eAIS ≥2).

Conclusions: A simple qualitative MRI Crohn's disease activity score appears predictive against a histopathological standard of reference.

Publication types

  • Research Support, Non-U.S. Gov't
  • Validation Study

MeSH terms

  • Adolescent
  • Adult
  • Aged
  • Algorithms*
  • Crohn Disease / pathology*
  • Female
  • Humans
  • Image Enhancement / methods
  • Image Interpretation, Computer-Assisted / methods*
  • Intestinal Perforation / pathology
  • Intestine, Small / injuries
  • Intestine, Small / pathology*
  • Magnetic Resonance Imaging / methods*
  • Middle Aged
  • Reproducibility of Results
  • Sensitivity and Specificity
  • Severity of Illness Index*
  • Young Adult