Patent ID: 6909284

Claim:
A planar MRI system having: (I) an open magnet configuration that produces a magnetic field having a remote region of substantial magnetic field homogeneity; (II) spatial encoding gradient coils; and (III) an RF coil; the open magnet configuration comprising: a ferromagnetic core having a substantially planar core surface layer and a longitudinal axis; and a unipolar current wire pair adjacent said planar core surface layer, the wire pair being separated along said longitudinal axis on an one side of the ferromagnetic core, the wire pair extending in a direction substantially perpendicular to the axis and substantially parallel to the planar core surface layer, the unipolar current wire pair providing a maximum magnetic field between the current wire pair along a direction perpendicular to said planar core surface layer and in said remote region of substantial magnetic field homogeneity, the planar core surface layer of the ferromagnetic core providing an orthogonal ferrorefraction effect, which provides the effect of generating a set of mirror image current wires of the same polarity on the opposite side of the ferromagnetic core, that substantially increases the resulting magnetic field compared to a magnetic field generated by the unipolar current wire pair in free space.