Validation and application of arterial spin labeling MRI for cerebral perfusion

Non-invasive evaluation of the cerebral blood flow (CBF) by means of arterial spin labeling (ASL) MRI offers an interesting alternative to currently used clinical perfusion measurement techniques. Where the current perfusion imaging techniques require the injection of an exogenous contrast-agent, ASL employs the blood that travels to the brain tissue as an endogenous tracer, for a non-invasive evaluation. However, due to the limited image quality and reliability of ASL measurements, the application of ASL was predominantly limited to highly specialized MRI centers. Recent technical developments in ASL research have elevated the quality and reliability of the technique to a level where it is ready for widespread ASL usage in clinical and research applications. However, with the focus mainly on technical improvements, several clinically relevant aspects such as patient comfort and quantitative performance have not been fully investigated to date. The main aim of this thesis was therefore to investigate such clinically relevant aspects.
The chapters in this thesis address a few of the important steps necessary into making ASL a clinically accepted technique for use in daily clinical practice. Where chapters 2 and 3 focus on improving patient comfort, chapters 4 to 6 address the performance of different ASL techniques with respect to the gold-standard perfusion measurement.