Abstract 3655: Development of a Large Scale Predictive Atlas of Clinical Outcome in Acute Ischemic Stroke

Abstract

Background: Neuroimaging studies including diffusion and perfusion-weighted imaging identify the location and neuroanatomic extent of brain ischemia in the acute phase of infarction. Although there has been substantial progress in using early neuroimaging studies to predict whether localized regions of brain tissue will proceed to infarction or recover, there has been little effort to define imaging parameters that predict which of the patient’s acute functional deficits will remain or resolve with potential recanalization/reperfusion treatments. This information may be particularly important in late time windows when the number of patients with salvageable penumbral tissue progressively declines. We previously reported development of a proof of concept acute stroke imaging atlas correlating DWI lesions and NIHSS items in a relatively small number of subjects. The goal of the current analysis was to expand this atlas to include a much larger number of cases. Methods: As part of a global project aimed at creating a large scale stroke-specific predictive brain atlas, we correlated acute DWI lesion location with the presence of individual sub-item scores from the NIHSS. Inclusion criteria were: acute ischemic stroke; brain MRI (including DWI) performed within 24 hours of symptom onset; and baseline NIHSS score available. Intramural NINDS provided the imaging and clinical data. Acute DWI images from all subjects were aligned to a common neuroanatomic coordinate system. Chi square images were calculated on a voxel-by-voxel basis. Results: A total of 400 patients were included in the analysis. Mean age was 69, range 21-98. Baseline NIHSS was median 5, mean 7, range 0-32. The figure shows representative axial slices from the atlas, including color-coded chi square values, using a false discovery rate of 5%, for anatomic regions in which there was a significant correlation between NIHSS sub-item symptom presence and DWI hyperintensity. Conclusions: Employing a large dataset including 400 acute stroke patients, we have developed a large scale voxel-based stroke atlas correlating NIHSS sub-items employing acute DWI lesion data. The maps illustrate the neuroanatomic representation of the NIHSS sub-items in standardized space. An important next step will incorporate acute diffusion and perfusion MR imaging to predict long-term outcome for two scenarios: untreated vs. treated with recanalization therapy. This information may then assist in guiding treatment decisions for late recanalization therapies.