Perihematomal Edema Is Greater in the Presence of a Spot Sign but Does Not Predict Intracerebral Hematoma Expansion

Background and Purpose - Perihematomal edema volume may be related to intracerebral hemorrhage (ICH) volume at baseline and, consequently, with hematoma expansion. However, the relationship between perihematomal edema and hematoma expansion has not been well established. We aimed to investigate the relationship among baseline perihematomal edema, the computed tomographic angiography spot sign, hematoma expansion, and clinical outcome in patients with acute ICH. Methods-Predicting Hematoma Growth and Outcome in Intracerebral Hemorrhage Using Contrast Bolus CT (PREDICT) was a prospective observational cohort study of ICH patients presenting within 6 hours from onset. Patients underwent computed tomography and computed tomographic angiography scans at baseline and 24-hour computed tomography scan. A post hoc analysis of absolute perihematomal edema and relative perihematomal edema (absolute perihematomal edema divided by ICH) volumes was performed on baseline computed tomography scans (n=353). Primary outcome was significant hematoma expansion (>6 mL or >33%). Secondary outcomes were early neurological deterioration, 90-day mortality, and poor outcome. Results-Absolute perihematomal edema volume was higher in spot sign patients (24.5 [11.5-41.8] versus 12.6 [6.9-22] mL; P<0.001), but it was strongly correlated with ICH volume (ρ=0.905; P<0.001). Patients who experienced significant hematoma expansion had higher absolute perihematomal edema volume (18.4 [10-34.6] versus 11.8 [6.5-22] mL; P<0.001) but similar relative perihematomal edema volume (1.09 [0.89-1.37] versus 1.12 [0.88-1.54]; P=0.400). Absolute perihematomal edema volume and poorer outcomes were higher by tertiles of ICH volume, and perihematomal edema volume did not independently predict significant hematoma expansion. Conclusions-Perihematomal edema volume is greater at baseline in the presence of a spot sign. However, it is strongly correlated with ICH volume and does not independently predict hematoma expansion.