New perspectives on the cerebral small vessels with 7T MRI

Pathological research suggests that conditions such as small vessel disease originate from abnormalities of the cerebral small blood vessels. Currently, 7T MRI enables us to measure blood flow velocity and pulsatility of the small cerebral perforating arteries. In this thesis these blood flow velocity and pulsatility measures play a central role, and various aspects of these measurements are investigated.

First, we focused on improving the accuracy and employability of the metrics. We therefore improved an existing method to detect the cerebral perforating arteries on MRI images, by decreasing the impact of subject movement during MRI scanning on the measurements. In addition, we aimed to increase the employability of the blood flow velocity and pulsatility measurements, by showing measurement feasibility on the much more available 3T MRI scanners.

Secondly, we investigated the cerebral perforating arteries within the cardiovascular system. We showed that the blood flow velocity and pulsatility measurements in the perforating arteries are altered in people with flow disruptions or arterial stiffness changes in the larger vessels preceding the perforating arteries. This indicates that perforating artery blood flow velocity and pulsatility are related to the functioning of the cardiovascular system.

Finally, we showed alterations of multiple aspects of the microvasculature in patients with a hereditary form of cerebrovascular disease. These findings also benefit research of non-hereditary small vessel disease due to their similarities.

This thesis increases the understanding of the role of the microvasculature in small vessel disease, and shows its dynamic nature and functioning as part of the cardiovascular system.