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:
Nov. 16, 2010
Filed:
Apr. 21, 2003
Anthony H. Aletras, Rockville, MD (US);
Anthony H. Aletras, Rockville, MD (US);
Abstract
Image contributions produced by an untagged specimen magnetization component in magnetic resonance imaging are controlled by applying one or more radiofrequency (RF) pulses that invert at least a portion of the untagged specimen magnetization. In an example, a specimen is tagged with a spatially modulated magnetization that is used to produce an image signal that includes a contribution associated with the tagged magnetization and an untagged magnetization. The untagged magnetization is substantially along an axial direction defined by an applied axial magnetic field. The untagged magnetization increases in magnitude because of so-called Trelaxation. A contribution to the image signal increases for a predetermined time or to a predetermined magnitude, and a 180-degree pulse is applied to invert at least a portion of the untagged magnetization. The untagged magnetization is then antiparallel with respect to the applied axial magnetic field. Additional inversion recovery causes the untagged magnetization to increase from a negative value to zero and then becomes positive. As a result, signal contributions associated with the untagged magnetization are reduced. Additional 180-degree pulses can be applied whenever the untagged magnetization becomes larger than a predetermined value so that image contrast can be maintained. When the tagged magnetization decreases to a predetermined level, an initial specimen magnetization is reestablished for subsequent imaging.