The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Aug. 07, 2001
Filed:
Sep. 02, 1999
Stuart S. Berr, Batesville, VA (US);
Vu Minh Mai, Brighton, MA (US);
Other;
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. The intensity is also a function of the relaxation rate of the inflowing spins, the partition coefficient of the spins, and the relaxation rate of the stationary tissue. Estimates on these values can be made and can be used to calculate a perfusion map, which is an image that is created in which the intensity of each voxel is proportional to the perfusion of spins into the voxel. EST MRI is entirely noninvasive and overcomes some of the problems associated with the other noninvasive MRI techniques.