Patent ID: 6346816
Filing Date: 2002-02-12
Classification: G01R

Abstract:
A magnet assembly for use in medical magnetic resonance imaging comprising:a ferromagnetic frame including two opposed ferromagnetic elements connected to ends of first and second opposing magnet pole supports, respectively; means for generating magnetic flux magnetically coupled to the ferromagnetic frame and disposed adjacent to each of the pole supports; and first and second ferromagnetic poles supported by the pole supports and magnetically coupled to the ferromagnetic frame, wherein the poles extend towards each other from the first and second pole supports, respectively, the first and second poles being spaced apart from each other to form a gap region therebetween defined by facing first and second surfaces of the respective poles for receiving a portion of a patient therein and for defining a first portion of the patient for scanning; wherein the first pole includes a ferromagnetic block having an end surface facing the second pole, the ferromagnetic block being movable toward the surface of the second pole to decrease the size of a portion of the gap region such that magnetic flux is increased in a portion of the gap region, defining a portion of the patient for higher resolution scanning than the first portion of the patient.