Patent ID: 8466681
Filing Date: 2013-06-18
Classification: A61B,G01R

Abstract:
1. An open-type MRI apparatus comprising: a pair of static magnetic field generating means disposed to face each other across a space for imaging an object to be examined; a pair of holding means configured to hold the pair of static magnetic field generating means at predetermined intervals, the pair of holding means being symmetrically disposed with respect to a central axis of the static magnetic field generating means; and a pair of tabular gradient magnetic field coil structures disposed on the imaging space side of the static magnetic field generating means, wherein the static magnetic field generating means includes an X-Y-Z coordinate system in the static magnetic field generating means in which a central axis of the facing static magnetic field generating means is set as a Z-axis, an axis which is orthogonal to the Z-axis and passes through a central axis of the pair of holding means is set as an X-axis, and an axis which is orthogonal to the X-axis and the Z-axis is set as a Y-axis, the tabular gradient magnetic field coil structures include an x-y-z coordinate system in the tabular gradient magnetic field coil structures in which an axis along the central axis of the static magnetic field generating means in the tabular gradient magnetic field coil structures is set as a z-axis, and two axes which are orthogonal to the z-axis, are orthogonal to each other, and are along respective gradient magnetic field directions are set as an x-axis and a y-axis, an x-y coordinate of the gradient magnetic field coil is disposed as to be rotated around z(Z) axis relative to an X-Y coordinate of the static magnetic field generating means, and the respective tabular gradient magnetic field coil structures are fixed to the facing static magnetic field generating means at a plurality of positions for suppressing distortions generated in the gradient magnetic field coil structures attributed to the Lorentz force which acts on the coil conductors upon applying a drive current to the gradient magnetic field coil.