SAR and temperature changes in the leg due to an RF decoupling coil at frequencies between 64 and 213 MHz

J W Hand, J J W Lagendijk, J V Hajnal, R W Lau, I R Young

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Abstract

Specific absorption rate (SAR) due to a butterfly surface coil in a realistic model of the leg was calculated for frequencies 64 less than or equal to nu less than or equal to 213 MHz. The resulting temperature distribution and temperature changes (DeltaT) were found using the bioheat transfer equation. To compare results at different frequencies, the minimum B-field within the coil's footprint in the plane parallel to the coil but displaced 50 mm from it was kept constant. To achieve the same minimum B-field as that associated with operation at 64 MHz that was compliant with safety guidelines (peak SAR in IL cm(3) of tissue of 2.3 W/kg), it was predicted that SAR would exceed recommended levels when nu greater than or equal to 149 MHz. The corresponding maximum DeltaT at 64, 128, and 213 MHz were 0.3, 1.3, and 5.0 degreesC, respectively. (C) 2000 Wiley-Liss, Inc.

Original languageEnglish
Pages (from-to)68-74
Number of pages7
JournalJournal of Magnetic Resonance Imaging
Volume12
Issue number1
Publication statusPublished - Jul 2000

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