Expanding the capabilities of arterial spin labeling MRI

Abstract

The main goal of this thesis is to further improve the ASL

methodology for cerebral perfusion imaging by means of technological

development. In this thesis, several new ASL techniques are proposed, which

cover the full breath of ASL-methodology, thereby enabling or improving the detection of different aspects of cerebral hemodynamics. VE-DASL is proposed to achieve fast cerebral flow territory mapping within 30 seconds. Time-encoded pCASL with a single voxel PRESS spectroscopic readout was implemented to detect multi-phase white matter perfusion in a highly time efficient manner. To better understand the signal generation mechanisms of IVIM, an ASL-preparation module was employed before an IVIM read-out, the diffusion properties of the blood pool were exclusively measured and the perfusion contribution was isolated. A novel method was proposed, optimized and validated to measure the labeling efficiency of pCASL directly by performing multi-phase pCASL imaging distal to the labeling plane. The longitudinal relaxation times of blood at different magnetic field strengths were measured and the expected gain in SNR by performing ASL at ultra-high magnetic field was quantified.