Abstract: A magnetic resonance technique to measure perfusion of fluid to tissue by inverting all the spins in fluid water hydrogen nuclei of the subject with a non-spatially-selective radiofrequency (RF) pulse and immediately reinverting the spins in an imaging plane of interest such that the spins in the imaging plane experience minimal perturbation of their magnetization while the spins outside the plane (extraslice) are inverted (tagged). To account for signal loss effects of magnetization transfer (MT), a control image is obtained by applying two non-selective inversion pulses and creating a perfusion-weighted image by subtracting the tagged image from the control image. When this tagged image is subtracted from a “control” image, the resulting intensity arises solely from the tagged spins that have flowed into the imaging plane. This resultant image is referred to as a perfusion weighted image, because its intensity is a function of the rate of perfusion into the imaging plane.