Digital Probabilistic Atlas of the Border Region between the Middle and Posterior Cerebral Arteries

Abstract

Background and Purpose: The diagnosis of external borderzone infarction is made when the stroke is located at the border between the arterial territories. Recent studies have raised questions regarding the location of this borderzone given the variability in the arterial territories. We examined the location of this region using a digital approach and its correspondence with the ‘traditional’ template. Methods: Infarcts resulting from occlusion of the middle cerebral artery (MCA) or posterior cerebral artery (PCA) trunk or branches were segmented from T₂-weighted MR images and linearly registered into a common stereotaxic coordinate space. For MCA infarcts and PCA infarcts, maps of voxels in a rim surrounding the infarct were created. The maps of individual rims were averaged to create images of the probability of each voxel lying in the MCA and PCA rims. The MCA and PCA rims were used to create a digital atlas of the probability of each voxel lying concurrently in both rims. Results: The MCA group consisted of 36 patients (16 males) with a median age of 73 (range 25–87) years. The PCA territory group consisted of 30 patients (24 males) with a median age of 61 (range 22–86) years. The probability of involvement in the digital atlas was higher in the posterior putamen (probability 0.12–0.29) and optic tract (probability 0.13–0.0.20) than in the angular gyrus (probability 0.01). Conclusion: We have created a digital model of the border region between the MCA and PCA territories. This approach may be useful for evaluating the likelihood of a stroke mechanism from topography.

Computer Modeling of Anterior Circulation Stroke: Proof of Concept in Cerebrovascular Occlusion

“…Thus, regional variations in arterial branching pattern additionally explain some of the differential effect of intracranial arterial occlusion on cortical arterial flow. These scenarios mirror clinical cases presented in Figure 3, the regional variation in infarct risk is published digital probabilistic maps in stroke patients (6) and other clinical case series (4). …”

“…However, the CoW may not offer sufficient protection when the site of occlusion is in the cortical arterial branches distal to the CoW. Further, there are several clinical reports of “sanctuary sites” in the brain, which are relatively protected from the effect of ischemia even in the setting of arterial occlusion (6, 13). These reports suggest that the LA may be of some importance in protecting the brain tissue, arguing for a need to develop better understanding of their role in ischemic stroke.…”

Dynamics of Regional Distribution of Ischemic Lesions in Middle Cerebral Artery Trunk Occlusion Relates to Collateral Circulation

“…Superficial compartments of the MCA territory, which are also reached by collateral blood flow through leptomeningeal arteries, were also spared from infarction in most patients, although involved in the acute perfusion lesion. Previous studies have used regional information on ischemic lesion distribution to generate maps of topographic lesion distribution (Phan et al, 2009), to correlate infarct location with stroke severity (Menezes et al, 2007), and to generate statistical outcome parameters on a voxelwise analysis (Wu et al, 2006). Our study exceeds previous digital maps Figure 2 Shows the probabilistic distribution of the six-lesion ROI in a standard MNI space superimposed on a mean image of spatially normalized nondiffusion-weighted (b = 0) images of patients with failed (left side, n = 13) and successful (right side, n = 18) recanalization.…”

Direct Exploration of the Role of the Ventral Anterior Temporal Lobe in Semantic Memory: Cortical Stimulation and Local Field Potential Evidence From Subdural Grid Electrodes

“…This is most probably because the common sources of neuroscience data on language and semantics are much less likely to “sample” this region. For example, middle cerebral artery (MCA) stroke (a primary source of information that underpins models of language and aphasia) typically does not damage the inferior-to-middle aspects of the ATL, because it is in the posterior cerebral artery-MCA watershed territory ( Phan et al 2005 , 2009 ). The same regions are often missing from functional neuroimaging studies due to a variety of technical reasons, including magnetic field inhomogeneities (for standard gradient EPI fMRI) and limited field of view ( Devlin et al 2000 ; Visser et al 2010 ).…”