MR imaging of patients with implanted drug infusion pumps.

The influence of magnetic resonance (MR) imaging on the integrity and function of an implantable, programmable drug infusion pump and the distortion of the image by this device were tested. Six identical pumps were tested in magnetic fields of 1.5 T. Pump memory was not affected by the procedure. The pump rotor stalled (no infusion) as long as the device was within the magnetic field. Drug delivery resumed as programmed after the pump was removed from the field. No structural damage to the electrical or mechanical pump components was detected. The pump caused a circular image artifact (a signal dropout) within 8-10 cm of the device. The authors conclude that MR imaging is accurate if the area of interest is at least 10 cm from the pump, and that with awareness of temporary infusion cessation, it is safe to perform MR imaging in patients with this implanted pump.