Patent ID: 6816047
Filing Date: 2004-11-09
Classification: G01R

Abstract:
A magnetic resonance imaging apparatus comprising:a pair of magnetic field generating means for generating a magnetic field in a first direction to form a desired uniform magnetic field space, said magnetic field generating means being formed in a doughnut-shape at a predetermined interval across said magnetic field space in a direction perpendicular to said first direction, each of said magnetic field generating means including a vacuum enclosure, cooling means and a group of magnetic field generating devices; said cooling means being arranged within said vacuum enclosure for containing and cooling said group of magnetic field generating devices; and supporting means for supporting said magnetic field generating means; each of said magnetic field generating devices including a first magnetic field generating device for generating a main component of said uniform magnetic field, a second magnetic field generating device for reducing a magnetic field generated outside said magnetic field generating means and a third magnetic field generating device for improving magnetic homogeneity of said uniform magnetic field, said first magnetic field generating device having a predetermined outer diameter greater than that of said third magnetic field generating device, and said second magnetic field generating device having an outer diameter at least equal to that of said first magnetic field generating device; and said first magnetic field generating device being arranged within said second magnetic field generating device relative to a direction of the magnetic field for forming said uniform magnetic field space at the center.