Preoperative intestine-to-liver CT ratio: useful predictor of resection in strangulated obstruction.

Background: Prompt diagnosis of strangulated bowel obstruction (SBO) is critical because delayed recognition can lead to life-threatening complications. This study assessed whether the intestinal-to-liver CT attenuation value ratio-a comparison of ischemic bowel-wall enhancement to liver enhancement-can predict the need for intestinal resection in SBO patients.

Materials and methods: We retrospectively analyzed 52 patients who underwent emergency surgery for suspected SBO from 2014 to 2021. Of these, 35 required intestinal resection due to irreversible ischemia (resection group), while 17 did not (no-resection group). Preoperative clinical and imaging findings were compared between groups.

Results: The resection group had a longer time from onset to surgery (p = 0.034) and higher leukocyte counts (p = 0.037). CT values of the poorly enhanced intestinal wall and the intestinal-to-liver attenuation ratio were significantly lower in the resection group (p < 0.0001). Multivariate analysis identified time to surgery (OR 5.08; 95% CI 1.106-23.350; p = 0.037) and CT attenuation ratio (OR 15.50; 95% CI 2.622-91.686; p = 0.0025) as independent predictors of resection. When stratified by the median ratio cutoff (< 0.40 vs. ≥ 0.40), resection rates were 92% and 44%, respectively (p = 0.0001). Additionally, CT attenuation ratio had the diagnostic performance (AUROC 0.886; Youden index 0.736; sensitivity 97.1% and specificity 76.5%.) CONCLUSION: An intestinal-to-liver CT attenuation ratio below 0.40 is a strong predictor of intestinal ischemia requiring resection in SBO patients.