ABSTRACT
Cerebral perfusion is a tightly regulated process to ensure that the metabolic demand of the brain is met at all times. As such, perfusion measurements offer insight in the function, and possible dysfunction, of the brain. Arterial spin labelling is a non-invasive MRI technique that uses magnetically labelled blood water as an endogenous tracer to measure perfusion. It can quantify a wide range of hemodynamic parameters, which together with its non-invasiveness makes it a valuable tool both for research and clinical settings. For example, in acute stroke, ASL can provide information on whole brain perfusion, perfusion territories and arterial transit time.
This chapter provides theoretical background and practical guidance for each stage of an ASL experiment. First, an overview is given on the possibilities of different sequences, after which we look into the acquisition parameters that provide optimal image quality. Once good-quality data are acquired, we discuss the options to convert the images to a quantitative measure of cerebral blood flow while minimising artefacts. Lastly, the current state of the technique and future perspectives are discussed.
