Wolfgang Driesel1, Toralf Mildner1, Andr Pampel1, Harald E. Mller1
1Max Planck Institute for Human
Cognitive and Brain Sciences,
Two versions of an anatomically shaped microstrip transmission-line (MTL) helmet coil were built: (A) a circularly polarized (CP) transmit/receive (Tx/Rx) coil and (B) a CP-Tx/eight-channel-Rx array. Curved MTL elements of different lengths were used to provide sufficient space for audiovisual stimulation and the electrical length was adjusted by proper termination. Both helmet coils generated an almost perfect circular polarization in a large portion of the human head extending into regions near the coil elements. Initial experiments verify that the designs permit imaging of the brain with good tissue contrast and potential for parallel imaging.