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:
Jan. 26, 1999
Filed:
Jul. 05, 1996
Andrew Li, South San Francisco, CA (US);
Toshiba America MRI, Inc., Tustin, CA (US);
Abstract
An improved MRI magnet structure is created by utilizing a lower pole mounting support with one or more vertically extending yokes. The one or more vertically extending yokes mount an upper pole mounting structure including an upper pole mounting ring and at least one spoke connecting the ring to at least one of the vertically extending structural supports. The average effective spacing of the upper pole mounting structure is greater than the air gap between the upper and lower pole thereby resulting in improved uniformity of the B.sub.o field at the patient imaging volume. In a preferred embodiment, a pie-shaped cryostat encompasses a plurality of radially distributed superconducting electromagnets for generating a more uniform field in the patient imaging volume. The patient imaging field uniformity in some embodiments can be improved by the use of shim coils and/or shim rings associated with either the upper or lower poles to further modify the field within the patient imaging volume.