Liquid infusion apparatus includes non-magnetic materials in a pumping structure and drive motor therefor, and in a controller that supplies drive signals to the motor to facilitate convenient operation in intense magnetic fields without distorting the magnetic fields and without radiating objectionable radio-frequency interference. A non-MRI-compatible liquid infusion apparatus is temporarily replaced with MRI-compatible, non-magnetic liquid infusion apparatus without disconnecting patient from an installed intravenous infusion set to continue infusing liquid within the MRI environment.
