TY - JOUR
T1 - In vivo radiofrequency heating in swine in a 3T (123.2-MHz) birdcage whole body coil
AU - Shrivastava, Devashish
AU - Utecht, Lynn
AU - Tian, Jinfeng
AU - Hughes, John
AU - Thomas Vaughan, J.
N1 - Publisher Copyright:
© 2013 Wiley Periodicals, Inc.
PY - 2014/10
Y1 - 2014/10
N2 - Purpose: To study in vivo radiofrequency (RF) heating produced due to power deposition from a 3T (Larmour frequency=123.2 MHz), birdcage, whole body coil. Methods: The RF heating was simulated in a digital swine by solving the mechanistic generic bioheat transfer model (GBHTM) and the conventional, empirical Pennes bioheat transfer equation for two cases: 1) when the swine head was in the isocenter and 2) when the swine trunk was in the isocenter. The simulation results were validated by making direct fluoroptic temperature measurements in the skin, brain, simulated hot regions, and rectum of 10 swine (case 1: n=5, mean animal weight = 84.0366.85 kg, whole body average SAR = 2.6560.22 W/kg; case 2: n=5, mean animal weight = 81.5966.23 kg, whole body average SAR=2.7760.26 W/kg) during 1 h of exposure to a turbo spin echo sequence. Results: The GBHTM simulated the RF heating more accurately compared with the Pennes equation. In vivo temperatures exceeded safe temperature thresholds with allowable SAR exposures. Hot regions may be produced deep inside the body, away from the skin. Conclusion: SAR exposures that produce safe temperature thresholds need reinvestigation.
AB - Purpose: To study in vivo radiofrequency (RF) heating produced due to power deposition from a 3T (Larmour frequency=123.2 MHz), birdcage, whole body coil. Methods: The RF heating was simulated in a digital swine by solving the mechanistic generic bioheat transfer model (GBHTM) and the conventional, empirical Pennes bioheat transfer equation for two cases: 1) when the swine head was in the isocenter and 2) when the swine trunk was in the isocenter. The simulation results were validated by making direct fluoroptic temperature measurements in the skin, brain, simulated hot regions, and rectum of 10 swine (case 1: n=5, mean animal weight = 84.0366.85 kg, whole body average SAR = 2.6560.22 W/kg; case 2: n=5, mean animal weight = 81.5966.23 kg, whole body average SAR=2.7760.26 W/kg) during 1 h of exposure to a turbo spin echo sequence. Results: The GBHTM simulated the RF heating more accurately compared with the Pennes equation. In vivo temperatures exceeded safe temperature thresholds with allowable SAR exposures. Hot regions may be produced deep inside the body, away from the skin. Conclusion: SAR exposures that produce safe temperature thresholds need reinvestigation.
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U2 - 10.1002/mrm.24999
DO - 10.1002/mrm.24999
M3 - Article
C2 - 24259413
AN - SCOPUS:84927691815
SN - 0740-3194
VL - 72
SP - 1141
EP - 1150
JO - Magnetic Resonance in Medicine
JF - Magnetic Resonance in Medicine
IS - 4
ER -