Hugo Kroeze1, Jeroen Stroeve1, Michel Italiaander1, Ingmar Voogt1, Giel Mens1, Peter R. Luijten1, Dennis W. J. Klomp1
1Radiology, UMC Utrecht, Utrecht, Netherlands
At high field MRI it is usefull to place the RF amplifiers directly on the coil. To avoid excessive heat in the bore, these amplifiers must be very efficient. A class-E amplifier was constructed with an efficiency of 80%. Class-E amplifiers can not amplify amplitude modulated signals, a modulator was added. This modulator was driven from a gradient waveform board. The amplifier was directly connected to a 50 mm loop coil. Images of a phantom and a wrist were made using this setup. This demonstrates that efficient on coil amplifiers can be connected to MRI scanners without major hardware modification.