From the macro- to the microvasculature : temporal and spatial visualization using arterial spin labeling

For many cerebrovascular diseases, visualization of blood flow through the large vasculature, as well as quantitative information on tissue perfusion, is very important. Arterial Spin labelling (ASL) magnetic resonance (MR) imaging enables the visualization of arterial flow by labelling the magnetization of arterial blood using radiofrequency pulses. The labelled arterial blood acts as an endogenous tracer and allows, which can avoid the reliance on the use of contrast agents. In this doctoral thesis, several new techniques for dynamic MR angiography and perfusion imaging were developed based on ASL techniques, which include pulsed ASL, pseudo-continuous ASL (pCASL), vessel-encoded pCASL, time-encoded pCASL as well as simultaneous multi-slice pCASL. The underlying motivation of these development is to reduce the burden on patients by employing non-invasive ASL techniques as potential alternatives to X-ray digital subtraction angiography, contrast-enhanced MR angiography and perfusion imaging. In each study, the optimum ASL techniques was carefully chosen by considering the pros and cons of the technique to achieve better clinical usability, while improving robustness against potential artifacts.LUMC / Geneeskund