Journal
MAGNETIC RESONANCE IN MEDICINE
Volume 66, Issue 1, Pages 255-263Publisher
WILEY
DOI: 10.1002/mrm.22790
Keywords
safety; radiofrequency; MRI; 7 T; bioheat
Funding
- National Institute of Health (NIH) [R01 EB007327, R01 EB000895, R01 EB006835, BTRR-P41 RR08079]
- Keck Foundation
Ask authors/readers for more resources
Temperatures were measured in vivo in four pigs (mean animal weight = 110.75 kg and standard deviation = 6.13 kg) due to a continuous wave radiofrequency (RF) power irradiation with a 31.75 cm internal diameter and a 15.24 cm long, 7 T (296 MHz), eight channel, transverse electromagnetic head coil. The temperatures were measured in the subcutaneous layer of the scalp, 5, 10, 15, and 20 mm deep in the brain, and rectum using fluoroptic temperature probes. The RF power was delivered to the pig's head for similar to 3 h (mean deposition time = 3.14 h and standard deviation = 0.06 h) at the whole head average specific absorption rate of similar to 3 W kg(-1) (mean average specific absorption rate = 3.08 W kg(-1) and standard deviation = 0.09 W kg(-1)). Next, simple bioheat transfer models were used to simulate the RF power induced temperature changes. Results show that the RF power produced uniform temperature changes in the pigs' heads (mean temperature change = 1.68 degrees C and standard deviation = 0.13 degrees C) with no plateau achieved during the heating. No thermoregulatory alterations were detected due to the heating because the temperature responses of the pre-RF and post-RF epochs were not statistically significantly different. Simple, validated bioheat models may provide accurate temperature changes. Magn Reson Med 66:255-263, 2011. (C) 2011 Wiley-Liss, Inc.
Authors
I am an author on this paper
Click your name to claim this paper and add it to your profile.
Reviews
Recommended
No Data Available