Patent ID: 6937126

Claim:
A magnetic coil assembly for use in an MRI system, said assembly comprising: a former; an annular drive coil; and an annular compensating coil; wherein, the former includes means for supporting the drive coil and means for supporting the compensation coil; the drive coil is disposed on the former, and is arranged to receive a current to run through the drive coil in a first direction, thereby generating magnetic fields; the compensating coil is disposed on the former, and has a common axis with the drive coil; the compensating coil is arranged to receive a further current to run through the compensating coil in a second direction, opposite to the first direction; the compensating coil has a diameter less than a diameter of the drive coil; the former is made of an easily magnetically saturated ferromagnetic material; and the former is configured to surround the compensating coil on axial sides and radially outer sides thereof, such that the compensating oil is magnetically attracted towards the former in a direction radially outward from the common axis.