Title:
GRADIENT COIL DEVICE AND MAGNETIC RESONANCE IMAGING DEVICE
Document Type and Number:
WIPO Patent Application WO/2012/096363
Kind Code:
A1
Abstract:
A gradient coil device has a major axis gradient coil (x main coil, 9x) and a minor axis gradient coil (y main coil, 9y). A cross section of the major axis gradient coil which is perpendicular to a center axis z direction has an ellipse shape, and the major axis gradient coil generates a gradient magnetic field in which a magnetic field strength is inclined in the major axis direction (x direction). A cross section of the minor axis gradient coil which is perpendicular to the center axis z direction has an ellipse shape, and the minor axis gradient coil generates a gradient magnetic field in which a magnetic field strength is inclined in the minor axis direction (y direction). A length Lmy of the minor axis gradient coil (9y) in the center axis direction is shorter than a length Lmx of the major axis gradient coil (9x) in the center axis direction. Magnetic energy of the minor axis gradient coil (9y) is equal to or less than magnetic energy of the major axis gradient coil (9x). The maximum value of a leak field by the minor axis gradient coil (9y) is equal to or less than the maximum value of the leak field by the major axis gradient coil (9x). As a result, the leak field of the minor axis gradient coil (9y) is reduced by extending a length of a shield coil (2b) in the z direction as little as possible.
Inventors:
TERADA MASANAO (JP)
ABE MITSUSHI (JP)
IMAMURA YUKINOBU (JP)
TAKEUCHI HIROYUKI (JP)
KUROME AKIRA (JP)
ABE MITSUSHI (JP)
IMAMURA YUKINOBU (JP)
TAKEUCHI HIROYUKI (JP)
KUROME AKIRA (JP)
Application Number:
PCT/JP2012/050547
Publication Date:
July 19, 2012
Filing Date:
January 13, 2012
Export Citation:
Assignee:
HITACHI MEDICAL CORP (JP)
TERADA MASANAO (JP)
ABE MITSUSHI (JP)
IMAMURA YUKINOBU (JP)
TAKEUCHI HIROYUKI (JP)
KUROME AKIRA (JP)
TERADA MASANAO (JP)
ABE MITSUSHI (JP)
IMAMURA YUKINOBU (JP)
TAKEUCHI HIROYUKI (JP)
KUROME AKIRA (JP)
International Classes:
A61B5/055; G01R33/421
Foreign References:
| JP2007296195A | 2007-11-15 | |||
| JPH021238A | 1990-01-05 | |||
| JP2007175438A | 2007-07-12 | |||
| JP2001112737A | 2001-04-24 | |||
| JP2001212107A | 2001-08-07 |
Other References:
T. N. BAIG ET AL.: "Shielding and energy advantages of capped elliptical coil structures", PROC. INTL. SOC. MAG. RESON. MED. 14, May 2006 (2006-05-01), pages #520
Attorney, Agent or Firm:
ISONO Michizo (JP)
Michizo Isono (JP)
Michizo Isono (JP)
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Claims: