| 摘要 |
An MRI static field magnet coil is symmetrical along the z-axis direction with a static field uniform region center substantially coincident with the center of the coil. However, the gradient field coil has asymmetrical density along the z-axis direction with the gradient field linear region center displaced from the center of the coil. One end of the gradient magnetic field coil in the z-axis direction forms the linear field region and the other end forms u current return portion. In order to make the gradient magnetic field linear region and the static magnetic field uniform region coincident with each other, the center of the gradient magnetic field coil is displaced from the center of the static field magnet. Thus, the gradient magnetic field coil can be extended from one end of the static field magnet until one end is aligned with one end of the static magnetic field uniform region. This permits the bore end of the gantry to be opened accordingly for greater patient comfort and/or medical access.
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