Magnetic resonance pre-polarization apparatus
AssigneePicker International, Inc.
InventorsIan Robert Young, John Frederick Eastham
Life of this patent
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Abstract
Interventional MRI imaging leads to the development of open magnets such as for example C-magnet 1, in which it is correspondingly more difficult to generate a large field in order to obtain a good signal-to-noise ratio. To overcome this, a pre-polarizing unit 7 is provided which utilizes a HTSC magnet, for example of YBCO, which is brought adjacent to the patient to assist in generating the main field, and then rapidly withdrawn to position 8, in order to enable the r.f. signals to be detected in the presence of the field of the C-magnet 1.
Claims21
An apparatus for use in magnetic resonance imaging, the apparatus comprising:
- a magnet for generating a main magnetic field in an imaging region;
- means for generating time varying gradient magnetic fields in the imaging region;
- means for exciting and detecting magnetic resonance in the imaging region;
- a high temperature superconducting pre-polarizing magnet, the high temperature superconducting magnet being rapidly movable from a first position nearer to the imaging region to a second position further from the imaging region;
- and
- means for moving the high temperature superconducting magnet between the first and second positions.
A method comprising:
- applying a main magnetic field within an imaging region of a magnetic resonance imaging apparatus using a magnet which includes first and second pole pieces disposed on opposite sides of an imaging region and a yoke joining the first and second pole pieces;
- placing an HTSC pre-polarizing magnet in proximity to the imaging region so as to impose a second magnetic field therein;
- exciting magnetic resonance in nuclei disposed in the examination region;
- moving the HTSC magnet away from the imaging region;
- and
- detecting signals indicative of magnetic resonance in the nuclei.
An apparatus for use in magnetic resonance imaging, the apparatus comprising:
- a magnet for generating a main magnetic field in an imaging region;
- means for generating time varying gradient magnetic fields in the imaging region;
- means for exciting and detecting magnetic resonance in the imaging region;
- a high temperature superconducting pre-polarizing magnet, the high temperature superconducting magnet being rapidly movable from a first position nearer to the imaging region to a second position further from the imaging region;
- and
- a first cooling member in thermal communication with the high temperature superconducting magnet when the high temperature superconducting magnet is in the second position.
An apparatus for use in magnetic resonance imaging, the apparatus comprising:
- a magnet for generating a main magnetic field in an imaging region, wherein the magnet for generating a magnetic field in the imaging region includes first and second pole pieces disposed on opposite sides of an imaging region and a yoke joining the first and second pole pieces;
- means for generating time varying gradient magnetic fields in the imaging region;
- means for exciting and detecting magnetic resonance in the imaging region;
- and
- a high temperature superconducting pre-polarizing magnet, the high temperature superconducting magnet being rapidly movable from a first position nearer to the imaging region to a second position further from the imaging region.
Dependencies are inferred from the claim text.