Nikolai I Avdievich1, Ioannis Giapitzakis1, Andreas Pfrommer1, and Anke Henning1,2
1High-field Magnetic Resonance, Max Planck Institute for Biological Cybernetics, Tübingen, Germany, 2Institute for Biomedical Engineering, University and ETH Zurich, Zurich, Switzerland
Ultra-high field (UHF) (>7T) transmit (Tx) and
transceiver surface loop phased arrays improve Tx-efficiency and homogeneity
for human brain imaging. Overlapping the loops enhances Tx-efficiency and SNR by
increasing the penetration depth. However, overlapping can compromise decoupling
and SNR by generating a substantial mutual resistance. Therefore, UHF Tx-arrays
are commonly constructed using gapped loops. Based on analytical optimization
we constructed a 9.4T 8-loop head transceiver array. Both the magnetic and
electric coupling were compensated at the same time by overlapping and excellent
decoupling was obtained. Tx- and Rx-performance of the array was compared favorably
to that of a gaped array.
