Quantitative analysis of hemorrhage volume for predicting delayed cerebral ischemia after subarachnoid hemorrhage

BACKGROUND AND PURPOSE - Delayed cerebral ischemia (DCI) is an important complication after subarachnoid hemorrhage and appears to be associated with clot burden on CT. Quantification of hemorrhage on digitized images may be a more accurate method for predicting DCI than qualitative scales. METHODS - Quantitative analysis of clot burden on CT was performed in 160 subarachnoid hemorrhage patients who were scanned within 24 hours from the symptom onset between June 25, 2005 and July 19, 2009. Cisternal plus intraventricular hemorrhage volumes (CIHV) were classified into quartiles to evaluate their association with DCI. DCI was defined as neurological deterioration or cerebral infarction, or both attributable to vasospasm. RESULTS - DCI occurred in 25% of the patients included (age, 55.4±14.5; male, 36.3%). Compared to the lowest quartile of CIHV (<9.6 mL), the higher quartile (9.6 mL-16.5 mL, 16.5 mL-31.0 mL, and ≥31.0 mL) was associated with a greater risk of DCI (odds ratio, 2.6, 4.1, and 6.1, respectively; P=0.01). Receiver-operating characteristic curve analysis showed that quantitative CIHV performed equivalently to the modified Fisher scale. Patients who had DCI develop in a specific vascular territory had higher amounts of blood volume in the corresponding cisterns. Patients in the highest quartile of CIHV also had a higher risk of death or severe disability at 3 months (71%) compared to other groups (23%, 19%, and 40% for first, second, and third quartiles, respectively). CONCLUSIONS - CIHV is a reasonable predictor for DCI and 3-month functional outcome in subarachnoid hemorrhage patients.