Revised Criterion for Identifying Small-Bowel Stricture in Crohn Disease at CT Enterography

Background Recent guidelines lowered the prestenotic dilatation threshold from >3 cm to ≥2.5 cm for diagnosing small-bowel stricture at CT enterography (CTE) in Crohn disease (CD). Its impact on stricture prevalence and risk stratification is unknown. Purpose To quantify the increase in stricture prevalence when applying a threshold of ≥2.5 cm and to assess whether risks for adverse outcomes are stratified according to the new threshold. Materials and Methods This retrospective study included patients with CD without acute obstructive symptoms who underwent CTE from 2017 to 2018 for routine follow-up of CD. Patients were classified into three groups: nonstricture, stricture with a prestenotic dilatation of 2.5-3 cm, and stricture with a dilatation of >3 cm. Stricture prevalence was calculated using both conventional and revised thresholds. Clinical outcomes during follow-up were analyzed using a Cox proportional hazards regression and Poisson regression, adjusting for relevant covariates. Results Among 1022 patients (median age, 35 years [IQR, 28-42 years]; 719 [70.4%] men), 190 (18.6%) had strictures with a prestenotic dilatation of >3 cm, and 137 (13.4%) had strictures with a prestenotic dilatation of 2.5-3 cm-a prevalence of 32.0% (327 of 1022 patients) using the new threshold. Compared with the nonstricture group, both stricture groups-2.5-3 cm and >3 cm-had a higher risk for emergency department visits (adjusted hazard ratios [HRs], 2.13 [P < .001] and 2.04 [P < .001], respectively; incidence rate ratio, 2.46 [P < .001] and 2.05 [P = .002]), small-bowel surgery (adjusted HRs, 2.27 [P = .006] and 3.58 [P < .001]), symptomatic obstruction (adjusted HRs, 7.99 [P < .001] and 6.25 [P < .001]), and small-bowel penetration (ie, de novo occurrence or progression of a sinus or fistula to an abscess or inflammatory mass) (adjusted HRs, 3.47 [P < .001] and 4.41 [P < .001]). Conclusion Applying a prestenotic dilatation threshold of ≥2.5 cm at CTE enabled identification of small-bowel strictures in additional patients with CD without acute obstructive symptoms, and these patients had increased risks of adverse clinical outcomes. © RSNA, 2026 Supplemental material is available for this article.