Abstract W P43: Extent of “Blooming Effect” Predicts Middle Cerebral Artery Recanalization After Intravenous Thrombolysis
Background and Purpose: Hemosiderin was shown to have a stronger T2 shortening effect than deoxyhemoglobin. Therefore, the extent of “blooming effect” of susceptibility vessel sign (SVS) might represent composition of different iron forms. We aimed to investigate the relationship between extent of overestimation of thrombus burden and middle cerebral artery (MCA) recanalization.
Methods: We retrospectively examined clinical and imaging data from consecutive acute ischemic stroke patients with MCA occlusion who underwent MRI before and 24 hours after IV thrombolysis in our hospital. A delayed phase contrast enhanced T1-WI was used to measure the true size of thrombus. We then examined the association of MCA recanalization and extent of overestimation of thrombus burden.
Results: We observed the presence of MCA SVS in 44 patients on initial gradient-recalled echo (GRE) scans and MCA recanalization in 21 (47.7%) patients 24 hours after treatment. The extent of overestimation of thrombus width on GRE was an acceptable predictor for MCA recanalization (odds ratio 1.584 per 10%; 95% CI: 1.090 to 2.310; p=0.016), with a receiver-operator characteristic of 0.884 (95% CI: 0.780 to 0.988; p < 0.001). The optimal cut-off point for predicting recanalization was identified at 1.7814, and this yielded a sensitivity of 87.0% and a specificity of 85.7%.
Conclusions: Overestimation of thrombus burden on GRE might reflect the content of hemosiderin. A larger overestimation might indicate aged thrombus, which were resistant to thrombolysis.
Author Disclosures: S. Yan: None. M. Lou: None.
- © 2015 by American Heart Association, Inc.