Abstract 48: Digital Brain Maps of 1018 Acute Supratentorial Large Artery Atherosclerotic Infarction

Abstract

Background: Current territorial maps are difficult to interpret because of highly variable territorial boundaries noted, thus complicating the assessment of stroke mechanism . Objective: To offer further knowledge on the variable anatomy of cerebral artery territory by providing terriorial maps of the anterior, middle, and posterior cerebral arteries (ACA, MCA, and PCA, respectively). Methods and Results: Digital maps of supratentorial infarcts were generated using diffusion-weighted MRIs of 1160 acute (<1w) stroke patients (67.0±13.3 years old, 53.7% male) recruited consecutively from 11 academic stroke centers in Korea. All had supratentorial infarction due to significant stenosis or occlusion of one of the three large supratentorial arteries, but with patent intracranial/extracranial carotid arteries. The three vascular territories were mapped individually by affected vessel, generating three datasets for which infarct frequency is defined for each voxel in the dataset. By mapping these three vascular territories collectively, we generated datasets showing the certainty index (CI) to reflect the likelihood of a voxel being a member of a specific vascular territory, calculated as either ACA, MCA, or PCA infarct frequency / total infarct frequency in that voxel. We defined border-zone maps using relative frequencies or CI differences. The volume of the MCA territory (54.1% of the supratentorial parenchymal brain volume) was about 3-fold bigger than the volumes of the ACA (13.3%) and PCA territories (13.8%). Quantitative studies using the maps showed that the medial frontal gyrus, superior frontal gyrus, and anterior cingulate were involved mostly in ACA infarcts, whereas the middle frontal gyrus and caudate were involved mostly by MCA infarcts. The PCA infarct territory was smaller and narrower than traditionally shown. Infarct territories in posterior upper brain regions were complex with a z-axis dependent order of involvement. The width of overlapping border-zones was relatively narrow in the anterior boundary of the MCA territory compared with its posterior boundary. Conclusion: The new topographic brain atlas can be used in clinical care and research to objectively define the supratentorial arterial territories and their borders.