Santillan, Cynthia

Abstract Background Computed tomography enterography (CTE) is frequently used to assess stricturing Crohn’s disease (CD). However, the reliability of CTE items used for assessment has not been established and there is no validated radiologic stricture severity index. Methods We conducted a retrospective study of 43 patients with symptomatic, terminal ileal stricturing CD. Four radiologists assessed a comprehensive list of pre-defined radiologic items potentially associated with stricture severity in 48 CTE scans in two separate rounds in random order. Reliability was quantified using the intraclass correlation coefficient (ICC). Items with at least moderate (ICC≥0.41) inter-rater reliability that were correlated with a visual analogue scale of overall stricture severity were candidate items for the development of a CTE stricture index. Results Inter-rater reliability was almost perfect for assessment of luminal diameter of pre-stenotic dilation (ICC 0.817 [95% confidence interval 0.703, 0.878]), substantial for stricture length (ICC 0.628 [0.419, 0.797]), and moderate for stricture wall thickness (0.482 [0.330, 0.601]). Intra-rater reliability was almost perfect (ICC ≥ 0.850) for all three items. A stricture severity index was derived and was well calibrated (optimism-adjusted calibration slope = 1.009), with scores calculated as the sum of stricture length (cm) + luminal diameter of pre-stenotic dilation (mm) + 5 x stricture wall thickness (mm). Conclusion Stricture length, prestenotic dilation, and stricture wall thickness can be reliably assessed, and are component items for a novel CTE stricture index (CTE-SI) of stricture severity for CD-related terminal ileal strictures. Additional external index validation for clinical and research contexts is required.

SummaryBackgroundReliable tools for patient selection are critical for clinical drug trials.AimTo evaluate a consensus‐based, standardised magnetic resonance enterography (MRE) protocol for selecting patients for inclusion in Crohn's disease (CD) multicenter clinical trials.MethodsThis study recruited 20 patients [Crohn's Disease Activity Index (CDAI) scores: <150 (n = 8); 150–220 (n = 4); 220–450 (n = 8)], to undergo ileocolonoscopy and two MREs (with and without colonic contrast) within a 14‐day period. Procedures were scored centrally using, Magnetic Resonance Index of Activity (MaRIA), and both Crohn's Disease Endoscopic Index of Severity (CDEIS) and Simplified Endoscopic Score (SES‐CD).Results37 MREs were acquired. Both MREs were evaluable in 16 patients for calculation of test–retest and inter‐reader reliability scores. The MaRIA scores for the terminal ileum had excellent test–retest and inter‐reader reliability, with correlations >0.9. The proximal ileum showed strong within‐reader agreement (0.90–0.96), and fair between‐reader agreement (0.59–0.72). MRE procedures were tolerable. MaRIA scores correlated with CDEIS and SES‐CD (0.63 and 0.71), but not with CDAI (0.34). MRE identified 3 patients with intra‐abdominal complications, who would otherwise have been included in clinical trials. Furthermore, both MRE and ileocolonoscopy identified active bowel wall inflammation in 2 patients with CDAI <150, and none in 1 patient with CDAI > 220. Data quality was good/excellent in 85% of scans, and fair or better in 96%.ConclusionsMagnetic resonance enterography of high‐quality and reproducibility was feasible in a global multi‐ centre setting, with evidence for improved selectivity over CDAI and ileocolonoscopy in identifying appropriate CD patients for inclusion in therapeutic intervention trials.