| 摘要 |
The present invention provides a permanent magnet arrangement, comprising: a. a mobile permanent magnet grouping; b. a facing plate constructed from ferromagnetic material; c. a an air gap defined by the spacing between said permanent magnet grouping and said facing plate; d. a yoke of predetermined shape formed from magnetically permeable material, said yoke holding said front surfaces of said magnets in a substantially parallel arrangement relative to said facing plate; e. means for individually moving said permanent magnets in said magnet grouping along an axis generally perpendicular to said facing plate; f. means for moving said permanent magnet grouping in a plane generally parallel to said facing plate; wherein a magnetic field within an active volume located in said air gap between said permanent magnet grouping and said facing plate is provided, said magnetic field sufficiently homogeneous for performance of MRI. |
