Abstract 3046: Co-registration and 3D Comparison Reveal a Variable Trajectory of Intracerebral Hemorrhage Expansion in Relation to Spot Sign Location: Analysis from the PREDICT Study
Background: Intracerebral hemorrhage (ICH) expansion can have devastating effects for patients. The spot sign, a form of contrast extravasation, has been shown to predict hemorrhage expansion. However, the relationship between the location of the spot sign within the ICH and the direction of hemorrhage expansion has not been defined. We hypothesized that the spot sign can predict the trajectory of ICH expansion.
Methods: Data from PREDICT, a prospective, observational cohort study coordinated at the University of Calgary, were used to conduct this case series. Non-contrast computed tomography (CT) and CT-angiography data were obtained for each subject. We used segmentation software to outline ICH volume on baseline and follow-up CTs. We then co-registered the scans and volumes in the same space to allow for three-dimensional voxel-to-voxel comparison along the x-, y-, and z-axes. This comparison yielded three points in three-dimensional space: the spot sign center of mass, the baseline ICH center of mass, and the follow-up ICH center of mass. Distances and angles between these points were used to classify four groups of ICH expansion: 1) perpendicular to the spot sign and baseline ICH center of mass; 2) away from the spot sign; 3) toward the spot sign; and, 4) circumferential.
Results: Eighty-two PREDICT study subjects exhibited spot signs. Forty were multiple spot signs and 42 were single spot signs eligible for this analysis. Seven subjects were excluded because of surgery or incomplete imaging. Sixteen subjects were not co-registered because of head motion or insufficient image quality. Nineteen single spot subjects were successfully co-registered. The radius of these 19 hemorrhages was 1.6±0.4 cm (assuming a sphere). The spot sign was located 1.4±0.6 times the length of the radius away from the baseline ICH center of mass. We classified nine co-registered subjects into the four groups because they showed significant hemorrhage expansion defined as ≥6 mL or ≥33% from baseline to follow-up. Four subjects exhibited hemorrhage expansion away from the spot sign, three exhibited circumferential hemorrhage expansion, and two exhibited hemorrhage expansion toward the spot sign. No hemorrhages expanded perpendicular to the spot sign.
Conclusion: The spot sign is generally located in the periphery of the ICH. Hemorrhages do not consistently expand in one specific trajectory from the spot sign. This study suggests that the spot sign location may not be useful to predict the direction of hemorrhage expansion.
- © 2012 by American Heart Association, Inc.