Magnetic resonance safety testing of a newly-developed fiber-optic cardiac pacing lead.
OBJECTIVE
To assess magnetic resonance (MR) safety for a newly developed, fiber-optic cardiac pacing lead.


METHODS
MR safety was assessed for the fiber-optic cardiac pacing lead by evaluating magnetic field interactions and heating. Translational attraction and torque were evaluated using a 1.5-Tesla MR system and previously described, standardized techniques. MR imaging-related heating was assessed using a 1.5-Tesla MR system and a transmit/receive, body radiofrequency (RF) coil with the fiber-optic lead positioned to simulate an in vivo condition in a saline-filled phantom. The phantom had dimensions similar to a human subject's torso and head. A fluoroptic thermometry system was used to record temperatures on and near the electrodes of the fiber-optic pacing lead at five-second intervals immediately before and during 20 minutes of MR imaging performed at a whole-body-averaged specific absorption rate (SAR) of 1.5 W/kg. Temperatures were also recorded from a reference site during this experiment.


RESULTS
Magnetic field interactions for the fiber-optic lead were minimal (deflection angle, 23 degrees; torque, +2). The highest temperature change recorded for the fiber-optic cardiac pacing lead and reference site was +0.8 degrees C.


CONCLUSIONS
The minor magnetic field interactions and relative lack of heating for the fiber-optic pacing lead indicate that it should be safe for patients with this device to undergo MR imaging procedures using MR systems operating at 1.5-T or less and at a whole-body-averaged SARs up to 1.5 W/kg.
Greatbatch Enterprises, Inc., Clarence, New York, USA.
Wilson
W
Greatbatch
Victor
V
Miller
Frank G
FG
Shellock
D004566:Electrodes; D004869:Equipment Safety; D006358:Hot Temperature / Q000009:adverse effects; D006801:Humans; D008279:Magnetic Resonance Imaging / Q000295:instrumentation / Q000592:standards*; D010138:Pacemaker, Artificial; D019047:Phantoms, Imaging