Volumetric blood cutoff for outcome prediction in aneurysmal subarachnoid hemorrhage using semiautomated quantification.

PURPOSE: Hemorrhage volume is a major prognostic factor in aneurysmal subarachnoid hemorrhage (aSAH). This study investigates the association between semiautomatically measured hemorrhage volumes and functional outcomes at discharge. METHODS: A retrospective cohort study was conducted including patients with aSAH admitted to a tertiary hospital between 2016 and 2021. Hemorrhage volumes-including subarachnoid (SAH), intraventricular (IVH), intraparenchymal (IPH), and total hemorrhage (TH)-were quantified from admission CT scans using semiautomated segmentation software (AW Server). Functional outcome was assessed with the Glasgow Outcome Scale (GOS) at discharge, dichotomized as favorable (GOS 4-5) or unfavorable (GOS ≤ 3). ROC curves were used to identify optimal volume thresholds, and multivariate logistic regression assessed independent associations. RESULTS: A total of 170 patients were included (65.3% women, mean age 58.5 years). Unfavorable outcomes were observed in 80 patients (47.1%). ROC analysis identified a TH volume > 29 cm3 as the optimal threshold for predicting poor outcomes, with an AUC of 0.791 (95% CI 0.721-0.861), sensitivity of 75.0%, and specificity of 73.3%. Other volume parameters (SAH, IVH, IPH) showed lower discriminatory power. In multivariate analysis, TH > 29 cm3 remained independently associated with unfavorable outcomes (OR: 3.872; 95% CI 1.704-8.799; p = 0.001), after adjusting for potential confounders. CONCLUSIONS: Semiautomated volumetric analysis of hemorrhage in aSAH identifies TH volume as a key predictor of unfavorable outcomes. TH volume could serve as a useful metric for early risk stratification and support clinical decision-making. Further prospective studies are needed to validate these findings and assess their broader applicability.