Preoperative imaging accuracy in Crohn’s Disease: MR and CT enterography versus intraoperative bowel length measurement in a single-center experience

Background Surgical planning in Crohn’s disease (CD) requires precise definition of diseased-bowel length to minimize unnecessary resection and short bowel syndrome. We assessed the accuracy of preoperative magnetic resonance (MR)- or computed tomography (CT)-enterography in predicting intraoperative measurements. Methods We retrospectively included consecutive patients undergoing primary or repeat ileocecal/ileal surgery (November 2017–April 2023) with recent MR or CT enterography. Two expert radiologists independently measured diseased small-bowel segments using a vessel-analysis software. A single surgeon measured the still-vascularized segment intraoperatively. Radiologic and operative lengths were compared using Pearson correlation and Bland–Altman analysis. Results A total of 81 patients were included (44% male; median age 42 years). Most underwent first surgery (92%); 34% had fistulizing and the remainder stenosing CD. Median radiologic length was 27 cm (range 3–205 cm) versus 30 cm intraoperatively (5–165 cm). Radiologic and intraoperative lengths were strongly correlated ( r 2 = 0.981; p < 0.01). Bland–Altman showed a mean bias of + 3.00 cm (SD 2.05) with limits of agreement −1.02 to +7.05 cm; 95% CI around these limits were ± 0.45 cm. Conclusions MR and CT enterography provide precise, accurate estimates of diseased-bowel extent and location in CD, supporting optimal surgical planning and risk stratification for short bowel syndrome, particularly in extensive disease or reoperations.