Electricity: measuring and testing – Particle precession resonance – Spectrometer components
Patent
1992-09-09
1994-03-22
Tokar, Michael J.
Electricity: measuring and testing
Particle precession resonance
Spectrometer components
324319, G01R 3320
Patent
active
052968103
ABSTRACT:
A superconducting magnetic imaging apparatus includes a vacuum vessel (40) having a central helium reservoir (48) in which superconducting magnetic coil windings (44) are maintained at a superconducting temperature. The vacuum vessel defines an internal bore (42) within which a self-shielded gradient coil assembly (14) and an RF coil (22) are received. The self-shielded coil assembly includes an inner former (60) which defines an imaging region (12) within which an imaged portion of the patient are received. X and y-gradient coils having winding patterns (62) are bonded to the former (60) forming an integral structure. A z-gradient coil (70) is mounted to mechanical reinforcement structure (72) to be held in a spaced relationship from the x and y-gradient coils with an air gap (74) in between. This facilitates the dissipation of heat generated by the large current pulses applied to the x and y-gradient coils. An outer former (80) of larger diameter than the z-gradient coils is received in the bore and supports the inner former therein. X, y, and z-gradient secondary or shielding coils (82, 84) are bonded to the outer former for preventing the gradients generated by the primary gradient coils from inducing gradient eddy currents in the vacuum vessel and the structures contained therein.
REFERENCES:
patent: 4733189 (1988-03-01), Punchard et al.
patent: 4737716 (1988-04-01), Roemer et al.
patent: 4876510 (1989-10-01), Siebold et al.
patent: 4881035 (1989-11-01), Siebold
patent: 4896129 (1990-01-01), Turner et al.
patent: 4905316 (1990-02-01), Okamoto
patent: 4978920 (1990-12-01), Mansfield et al.
patent: 5132618 (1992-07-01), Sugimoto
"Active Magnetic Screening of Gradient Coils in NMR Imaging", Mansfield, et al., Journal of Magnetic Resonance 66, 573-576 (1986).
"Active Magnetic Screening of Coils for Static and Time-Dependent Magnetic Field Generation in NMR Imaging", Mansfield, et al., J. Phys. E. Sci. Instrum. 19 (1986).
"Minimum Inductance Coils", Turner, J. Phys. E. Sci. Instrum. 21 (1988) 948-952.
Picker International Inc.
Tokar Michael J.
LandOfFree
MRI self-shielded gradient coils does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with MRI self-shielded gradient coils, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and MRI self-shielded gradient coils will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-439461