Background and purpose:
Chronic lesion locations are associated with neurologic outcomes. However, voxel-based acute infarct maps have not been used to predict long-term deficits and outcomes. The combination of ischemic lesion volume and location may aid in acute outcome prediction models. We evaluated the feasibility of voxel-based lesion mapping in acute ischemic stroke patients.
Methods:
In a retrospective study of patients with suspected middle cerebral artery (MCA) territory strokes, we identified acute infarcts on the diffusion-weight imaging (DWI; b=1000) sequences and confirmed them on the apparent diffusion coefficient (ADC) sequences using a semi-qualitative approach. Only patients with all three sequences available were included in the study. We then manually created a lesion map for each patient. Lesions were overlaid on T1-weighted images and transformed to standardized stereotactic space. We overlaid the volumetric lesion masks from all patients to create a composite acute lesion atlas.
Results:
Among 164 patients, 5 (3.1%) patients had no clear acute lesion and 9 (5.5%) had technical problems with normalization or overlaying, leaving 150 (91.5%) patients for analysis (mean age 66.1 years; 52.0% male; 66.7% white; median NIHSS scale 4). A composite acute lesion atlas was developed (Figure) with regions of high overlap easily visible, suggesting high statistical power for acute lesion-outcome prediction modeling.
Conclusion:
Acute ischemic lesions can be reliably mapped and used to create aggregated infarct atlases. The considerable overlapping regions in stroke patients might provide sufficient power to detect highly correlated lesion-outcome relationships. The proposed technique may provide a time-sensitive method for identifying acute infarct location, predicting the course of recovery, and selecting patients for early interventions.
ACUTE LESION VOLUME PREDICTS CHRONIC VOLUME REGARDLESS OF ABLATION PARAMETERS, ENERGY SOURCE OR ABLATION LOCATION
