Dynamic susceptibility contrast (DSC): Gadolinium contrast is injected, and rapid repeated imaging (generally gradient-echo echo-planar T2 weighted) quantifies susceptibility-induced signal loss.[54] Dynamic contrast enhanced (DCE): Measuring shortening of the spin–lattice relaxation (T1) induced by a gadolinium contrast bolus.[55] Arterial spin labelling (ASL): Magnetic labeling of arterial blood below the imaging slab, without the need of gadolinium contrast.[56]