Patent ID: 6891375

Claim:
An MRI apparatus, comprising: a temperature regulator device configured to adjust local temperature of at least one of permanent generating magnets, yoke, and deflectors of a static field generator magnet, wherein said static field generator magnet generates a static magnetic field and said temperature regulator device is configured to adjust said local temperature of the at least one of said permanent generating magnets, yoke, and deflectors to control uniformity of the static magnetic field; and a separate block of permanent magnetic material including at least one of a heater configured to increase said local temperature and a cooler configured to decrease said local temperature, wherein said separate block of permanent magnetic material is embedded within at least one of said permanent generating magnets, yoke, and deflectors, said separate block of permanent magnetic material is different from at least one of said permanent generating magnets, yoke, deflectors, heater and cooler, and at least one of said heater and cooler are configured to be controlled by said temperature regulator device.