EVALUATION OF MAGNETIC RESONANCE SAFETY OF VETERINARY RADIOFREQUENCY IDENTIFICATION DEVICES AT 1 T
Article first published online: 11 NOV 2010
© 2010 Veterinary Radiology & Ultrasound
Veterinary Radiology & Ultrasound
Volume 52, Issue 2, pages 161–167, March/April 2011
How to Cite
BAKER, M. A. and MACDONALD, I. (2011), EVALUATION OF MAGNETIC RESONANCE SAFETY OF VETERINARY RADIOFREQUENCY IDENTIFICATION DEVICES AT 1 T. Veterinary Radiology & Ultrasound, 52: 161–167. doi: 10.1111/j.1740-8261.2010.01762.x
- Issue published online: 9 MAR 2011
- Article first published online: 11 NOV 2010
- Received March 8, 2010; accepted for publication September 29, 2010.
- MR safety;
- radiofrequency identification device;
- small animal imaging
Implants containing metallic components have the potential to become heated or move within the patient while in the magnetic resonance (MR) environment. Despite containing a ferromagnetic core and having been in use for over 20 years, no information is available on the safety of veterinary radiofrequency identification devices during MR examinations. These devices are the most commonly encountered metallic implants in dogs and cats undergoing MR imaging. Three commercial veterinary microchips were evaluated for safety in the MR environment at 1 T. Parameters tested were translational force, torque, heating, artifact production, and function. Translation and torque were larger than that expected from normal activity under normal gravity. No significant heating was observed. Signal void artifacts may affect diagnosis if they are too close to the area of clinical importance. Microchip function was unaffected by routine clinical MR imaging. Capsule formation around devices is a major factor in counteracting translation and torque. Our findings support that is acceptable for patients to undergo MR imaging with this 1 T system following an interval of 3 months postimplantation to allow capsule growth. Because of the complex interactions involved, these observations may not be translatable to MR scanners of different field strength and/or manufacturer. Further safety testing of these and other radiofrequency identification devices is therefore recommended at different field strengths and equipment specifications.