An infrared radiant heating system for raising or maintaining a uniform core temperature of the body of a patient during surgery, substantially without affecting the temperature of the area surrounding the patient’s body, includes an infrared radiant heater located near the patient to provide radiant heat to the entire body or one or more parts of the body of the patient. A gate wire is below the passivation film. Subsequent to the priming, steady state magnetic resonance imaging data at the first spectral offset is acquired using a magnetic resonance imaging scanner. Provide a housing material in the runner, and then curing the housing material.