Patent ID: 11867780
Assignee: VICTORIA LINK LIMITED
Field: Measurement (Instruments)
Classification: CPC G  A | IPC A  G

Claim 0:
1. A magnet for use in an apparatus for performing magnetic resonance imaging (MRI) of a patient's head, wherein the magnet is an asymmetric magnet comprising a plurality of superconducting coils that are positioned around a cylindrical axis to provide a magnetic field on the cylindrical axis, the cylindrical axis defining an axial direction of the magnet, wherein the magnet comprises:
a patient end arranged to be positioned adjacent or against a patient's shoulders with the patient's shoulders outside the magnet; and
a recess for receipt of the patient's head extending into the magnet from the patient end,
wherein the magnet is configured to provide an offset imaging volume in the recess, wherein the imaging volume has an isocentre that is positioned closer to the patient end of the magnet than to the opposite end of the magnet;
wherein the magnet comprises at least three groups of coils in a generally tapering arrangement, with a first group of coils positioned at or toward the patient end having a larger transverse outer dimension than a transverse outer dimension of a second group of coils positioned further from the patient end, and a third group of coils positioned at or toward an opposite end of the magnet having a transverse outer dimension that is smaller than the transverse outer dimension of the second group of coils; and
wherein the magnet further comprises an additional group of coils, wherein the first group of coils overlaps the additional group of coils in the axial direction, such that a bottom portion of the additional group of coils is positioned closer to the patient end of the magnet than a top portion of the first group of coils.