Clinical Usefulness of Computed Tomography Enterography as a Diagnostic Modality for Isolated Terminal Ileitis

Guidelines for further diagnostic evaluation in patients with isolated terminal ileitis have not been established. Although computed tomography enterography (CTE) is an established modality for small bowel evaluation, its diagnostic value in this setting remains unclear. This study aimed to evaluate the diagnostic utility of CTE in patients with isolated terminal ileitis identified during ileocolonoscopy and to identify patient subgroups most likely to benefit from additional CTE evaluation.

We retrospectively reviewed the medical records of 98 patients who were diagnosed with terminal ileitis without colonic abnormalities during ileocolonoscopy at a tertiary referral center between October 2005 and July 2021. A positive CTE finding was defined as the presence of a lesion in the proximal small bowel beyond the terminal ileum. Independent predictors of positive CTE findings were evaluated using logistic regression analysis.

The mean patient age was 43.8 years, and 59.2% were male. Positive CTE findings were identified in 48 patients (49.0%). The most common final diagnosis among these patients was Crohn's disease (n=36, 75.0%). Multivariate analysis revealed that an elevated erythrocyte sedimentation rate (>10 mm/hr) (odds ratio [OR], 3.057; p=0.040), older age (>60 years) (OR, 7.392; p=0.002), and mucosal erythema in the terminal ileum on ileocolonoscopy (OR, 12.078; p=0.030) were independent predictors of positive CTE findings.

Approximately half of patients with isolated terminal ileitis had positive CTE findings, with Crohn's disease being the most frequent final diagnosis. CTE may be particularly useful in patients with elevated erythrocyte sedimentation rate (>10 mm/hr), age >60 years, or mucosal erythema in the terminal ileum.