<unk>  (ASL), also known as<unk> <unk>  tagging, is a magnetic resonance imaging technique used to quantify cerebral blood perfusion by<unk>  blood water as it flows throughout the brain. ASL specifically refers to magnetic<unk>  of<unk>  blood below the imaging slab, without the need of gadolinium contrast, which is the first of its kind in terms of perfusion imaging. A number of ASL schemes are possible, the simplest being flow alternating inversion recovery (FAIR) which requires two acquisitions of identical parameters with the exception of the out-of-slice saturation; the difference in the two images is theoretically only from inflowing<unk> s, and may be considered a 'perfusion map'. The ASL technique was developed by Alan P. Koretsky, Donald S. Williams, John A. Detre and John S. Leigh, Jr in 1992.
Arterial spin labelling
Perfusion scanning
Blood-oxygen-level-dependent imaging
Perfusion MRI
Disease diffusion mapping
Functional near-infrared spectroscopy
Oxygen enhancement ratio
Intravascular fluorescence