Vascular Territory Segmentation Software

The visualization and quantification of the perfusion territories from major feeding arteries in the brain is important for many clinical applications, including arterial stenosis and ischemic stroke. Current MRI processing techniques that monitor this activity in the brain are limited because they require manual intervention and post-processing. Often this manual approach leads to inaccurate visualization of perfusion in the brain.

The current limitations in monitoring vessel territory may increase the likelihood of a clinician missing the signs of arterial stenosis or ischemic stroke. In the presence of arterial stenosis or ischemic stroke, blood flow is restricted and blood supply decreases to the parts of the brain fed by corresponding vessels. Often collateral circulation increases in the brain as a mechanism to bypass and compensate for blockage in a main artery. This increased collateral flow can supply enough oxygenated blood to maintain adequate cerebral perfusion for supporting brain function. Such collateral circulation masks stenosis or stroke symptoms, creating the need for non-invasive clinical exams to determine levels of stenosis or occlusion in symptom-free patients.

Initial testing on the technology using a Siemens Skyra 3T scanner on 20 normal patients has been completed. Vascular territory maps were created with a Fourier Encoded Arterial Spin Labeling technique with 2D Echo Planar Imaging acquisition. Results of the vascular territory maps show the anterior and middle cerebral regions are supplied via the internal carotid arteries and the posterior cerebral region supplied from the vertebral arteries. This technology showed unique patient variability in the probabilistic territory maps which would not be possible with current conventional vascular territory mapping.

• Youngkyoo Jung, PhD, Department of Radiology