Title:
MAGNETIC RESONANCE DEVICE AND METHOD TO PERFORM SHIM OF MAGNETIC RESONANCE DEVICE
Document Type and Number:
Japanese Patent JPH08224220
Kind Code:
A
Abstract:
PROBLEM TO BE SOLVED: To offer an MRI apparatus that makes not only an axis-inclination but also a lateral inclination of sim possible and a system which puts shim into practice. SOLUTION: Pitch wave distortion component which is bigger than Z 6 formed by Magnet 10 surrounding a subject receiving bore 12 is decreased by shim. A magnetic field probe 80 measures pitch wave at the enough number of axis-positions by measuring the magnetic field in the inside of the bore 12. For instance, the magnetic field probe 80 measures up to harmonic distortion Z 12 at twenty-four axis-positions. All the existing lateral spherical pitch waves are sampled at a specified number of angular increments 32-36. Iron shim is provided with the inside of the pocket of shim tray in the hole and adjusts Z 12 and sampled pitch waves which are bigger than Z 6. The shim trays have a sufficient number of pockets, for example, twenty-four pockets axially along the bore to compensate for the Z 12 harmonic.
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Inventors:
BUITSUSHIYUNUU SHII SURIBASUTA
JIYON BUI EMU MATSUKUGINREI
GOODON DEI DEIMIISUTAA
JIYON BUI EMU MATSUKUGINREI
GOODON DEI DEIMIISUTAA
Application Number:
JP30991995A
Publication Date:
September 03, 1996
Filing Date:
November 02, 1995
Export Citation:
Assignee:
PICKER INT INC
International Classes:
A61B5/055; G01R33/3873; (IPC1-7): A61B5/055; G01R33/3873
Attorney, Agent or Firm:
Nobuyuki Iida