Patent ID: 7116198

Claim:
A magnetic structure for generating a substantially uniform magnetic field capable of implementing MRI imaging of a body part of a patient within a region of interest, comprising: a) first ( 52 ) and second ( 54 ) magnetic structures defining a first cavity ( 30 ) having the region of interest and configured to accommodate a body part of a patient and defining adjacent the first cavity a second cavity ( 58 ), larger than the first cavity, the first and second magnetic structures being positioned on opposite sides of the first and second cavities and defining a common longitudinal axis (Z) through the centers of the first and second magnetic structures and providing access from the outside for surgical intervention to the body part of the patient when positioned within the first cavity, characterized in that: b) each of the first and second magnetic structures comprises: i) an outer conically-shaped permanent magnetic section ( 34 ) having a conical axis and having a narrow end adjacent the first cavity, ii) an inner permanent magnetic section ( 36 ) having a central axis, iii) an intermediate permanent magnetic section ( 40 ) integrally connecting the inner and outer permanent magnetic sections, c) the inner permanent magnetic section ( 36 ) having a recess ( 39 ) at the central axis, d) the intermediate permanent magnetic section ( 40 ) having a surface ( 38 ) bounding the recess ( 39 ), e) the outer surface ( 35 ) of the outer conically-shaped permanent magnetic section ( 34 ) being aligned with an angle θ 0 constituting the outer cone angle of the outer conically-shaped permanent magnetic section ( 34 ), f) the surface ( 38 ) bounding the recess ( 39 ) being aligned substantially with an angle θ 1 constituting the inner cone angle of the outer conically-shaped permanent magnetic section ( 34 ), g) the permanent magnetic sections being configured to produce within the region of interest in the first cavity a substantially uniform magnetic field (H) capable of implementing MRI imaging of the body part when present in the first cavity.