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.