Sung-Min Sohn1, Anand Gopinath1, J. Thomas Vaughan1,2
1Electrical & Computer Engineering, University of Minnesota, Minneapolis, MN, United States; 2Center for Magnetic Resonance Research, University of Minnesota, Minneapolis, MN, United States
RF coil based on microstip transmission lines, the TEM coil, has been widely used for high-field MRI and has narrow bandwidth due to its high quality factor (Q). Although high Signal-to-Noise Ratio (SNR) of MR coils is obtained from this property it has a critical drawback, human body (loading) effect that causes the resonance frequency and Q of RF coil to change when different human bodies are loaded. This work proposes an adaptive impedance matching technique to avoid mismatch of the RF loaded coils at the Larmor frequency and alternative manual tuning that needs a several minutes and remains a major obstacle to the use of TEM coils in ultra-high-fields MRI systems.