Cerebral blood velocity of small intracortical blood vessels in macaque monkey measured by quantitative phase-contrast MRI at 7T

Motivation: Fine-scale functions of the cerebral cortex are shaped by vascular hemodynamics; however, there is still a lack of knowledge about the velocity of small intracortical vessels in primates. Goal(s): To quantify the cerebral blood velocity of small intracortical vessels in non-human primates using a conventional human 7 T scanner. Approach: Using non-human primate model, phase-contrast MRA images were acquired using a 7T large-bore MRI scanner with 64-μm in-plane resolution. Results: We show the accessibility to measure blood velocity of small intracortical vessels using a 7T large-bore MRI scanner. The mean blood velocity and radius of intracortical vessels are 7.3 mm/s and 43 μm. Impact: Using a standard human 7T MRI scanner, we measured the velocity of micron-scale intracortical vessels non-invasively in primates. This study paves the way to understand intracortical vessel function in relation to functional organization and clinical application using non-human primate model.