Automated Hemorrhage Volume Quantification in Aneurysmal Subarachnoid Hemorrhage

Abstract Background The volume of hemorrhage is a critical factor in predicting outcomes following aneurysmal subarachnoid hemorrhage (aSAH). Although grading scales such as the Fisher score are extensively used, their subjective nature can lead to inaccuracies in quantifying the total volume of blood. We analyzed a large cohort of patients with aSAH with an automated software for the precise quantification of hemorrhage volume. The primary aim is to identify clear thresholds that correlate with the likelihood of complications post-aSAH, thereby enhancing the predictive accuracy and improving patient management strategies. Methods An automated algorithm was developed to analyze non-contrast computed tomography scans of aSAH patients. The algorithm categorized tissues into blood, gray matter, white matter, and cerebrospinal fluid, isolating the blood for volume quantification. Receiver operating curve analysis was done to establish thresholds for vasospasm, acute hydrocephalus, shunt-dependent hydrocephalus (SDH), and death within 7 days. Additionally, we determined if there is any relationship between the aneurysm size and the amount of hemorrhage. Results A total of 500 aSAH patients and their respective aneurysms were analyzed. Hemorrhage volume was significantly higher in patients with vasospasm (21.7 [10.9, 41.4] vs 10.7 [4.2, 26.9], p < 0.001), acute hydrocephalus (22.7 [9.2, 41.8] vs 5.1 [2.1, 13.5], p < 0.001), SDH (23.8 [11.3, 40.7] vs 11.7 [4.1, 28.2], p < 0.001), and those who died before 7 days (52.8 [34.6, 90.6] mL vs 14.8 [5.0, 32.4] mL, p < 0.001) compared to their counterparts. Notably, specific hemorrhage thresholds were identified for each complication: 15.16 mL for vasospasm (65% sensitivity and 60% specificity), 9.95 mL for acute hydrocephalus (74% sensitivity and 69% specificity), 16.76 mL for SDH (63% sensitivity and 60% specificity), and 33.84 mL for death within 7 days (79% sensitivity and 77% specificity). Conclusion Automated blood volume quantification tools could aid in stratifying complication risk after aSAH. Established thresholds for hemorrhage volume related to complications could be used in clinical practice to aid in management decisions.