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:
Feb. 02, 1999
Filed:
Jul. 25, 1996
Hiromi Kawamoto, Yaita, JP;
Kabushiki Kaisha Toshiba, Kawasaki, JP;
Abstract
In a magnetic resonance imaging apparatus, gradient magnetic fields and a radiofrequency magnetic field are applied to a subject placed in a static magnetic field to excite nucleuses and generate magnetic resonance signals. A magnetic resonance image is reconstructed on the basis of the magnetic resonance signals. The gradient magnetic fields are produced by gradient coils. A very high-speed imaging method such as an echo planar method requires shield coils to magnetically shield, to the outside, the magnetic fields generated by the primary coils. It is very difficult to drive the primary coils and the shield coils by one amplifier to raise gradient magnetic fields having a relatively high strength within a short period of time. The primary coils and the shield coils are divided into a plurality of groups, and currents are individually supplied to the plurality of groups to allow to raise the gradient magnetic fields having a relatively high strength within the short period of time.