Title :
Heating near implanted medical devices by the MRI RF-magnetic field
Author :
Nyenhuis, J.A. ; Kildishev, A.V. ; Bourland, J.D. ; Foster, K.S. ; Graber, G. ; Athey, T.W.
Author_Institution :
Hillenbrand Biomed. Eng. Center, Purdue Univ., West Lafayette, IN, USA
fDate :
9/1/1999 12:00:00 AM
Abstract :
The temperature rise in the vicinity of a medical implant due to the RF field in Magnetic Resonance Imaging (MRI) was evaluated. For the calculations, the implant was taken to be a conducting cylinder resembling the geometry of a commercial infusion pump. Measurements of temperature rise were made with the pump in a phantom in a clinical imager. The RF protocol was 20-minutes long and produced a specific absorption rate (SAR) of 0.95 W/kg in the 34-kg phantom. In the measurements, the maximal temperature rise near the implant (0.66°C) was about 3 times the control rise (0.23°C) with no implant. The calculations are consistent with experiment
Keywords :
biomedical MRI; biothermics; prosthetics; radiofrequency heating; 20 min; MRI RF-magnetic field; RF protocol; clinical imager; commercial infusion pump; conducting cylinder; control rise; implanted medical devices; specific absorption rate; temperature rise; Biomedical imaging; Geometry; Heating; Imaging phantoms; Implants; Magnetic field measurement; Magnetic resonance imaging; Protocols; Radio frequency; Temperature measurement;
Journal_Title :
Magnetics, IEEE Transactions on
