Semiautomated Hemorrhage Volume Quantification in Aneurysmal Subarachnoid Hemorrhage.

Background: The volume of hemorrhage is a crucial factor in predicting outcomes following aneurysmal subarachnoid hemorrhage (aSAH). Although grading scales such as the Fisher score are widely used, they can lead to inaccuracies in quantifying the total blood volume because of their reliance on visual assessment. We analyzed a large cohort of patients with aSAH with a semiautomated software for the precise quantification of hemorrhage volume. The primary aim is to identify clear thresholds that correlate with the likelihood of complications after aSAH, thereby enhancing the predictive accuracy and improving patient management strategies.

Methods: A semiautomated algorithm was developed to analyze noncontrast computed tomography scans of patients with aSAH. 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 (SDHC), and death within 7 days.

Results: A total of 500 patients with aSAH 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), SDHC (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 with 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 SDHC (63% sensitivity and 60% specificity), and 33.84 mL for death within 7 days (79% sensitivity and 77% specificity).

Conclusions: Semiautomated 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.