Article
Calculation and visualization of the vascular territories and watersheds of the major brain arteries
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Published: | May 20, 2009 |
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Objective: Advanced neurovascular procedures and tumor resections necessitate careful consideration of vascular anatomy. It has been shown that individual differences in the branching patterns of the major brain arteries do exist. We hereby present our ongoing work to quantitatively calculate and visualize the vascular territories and watersheds of the major brain arteries based on routine magnetic resonance imaging (MRI).
Methods: From five routine time-of-flight MRI sequences, the vascular tree was segmented using a specialized vascular region-growing algorithm. The extracted vessel tree was then skeletonized and transformed into a spatial description of the blood vessels. Additionally, vessel diameters and branching patterns were recorded. After 3D visualization and validation of the virtual vessel tree, relative vascular supply of scanned brain tissue by the major brain arteries (Aa. cerebri anteriores, mediae and posteriores) was calculated. A next-neighbor and distance algorithm was used to estimate the relative vascular supply for each voxel of brain tissue. The results were visualized using volume and surface-based rendering. Furthermore, volumetric analysis of the resulting vascular territories was accomplished.
Results: In five out of five patients, it was possible to calculate, visualize and volumetrically analyze the supratentorial vascular territories and the watersheds of the six major cerebral arteries. Vascular supply of the basal ganglia as well as the brain stem could not be successfully calculated due to the limited spatial resolution of the imaging material. Our imaging and post-processing techniques need to be further refined to include more distal branches of the brain arteries. Finally, the results need to be validated in an experimental setting using corrosion casts, for example.
Conclusions: Using refined imaging techniques and advanced MRI scanners, it should be possible to include the vascular anatomy and territories into surgical planning and decision making in neurosurgery.