Triple-tunable birdcage coil for frequency selection in PET/MRI systems

Motivation: The PET insert can be used with MRI systems of different magnetic field strengths; however, a radio frequency(RF) coil cannot be used with different tesla. Goal(s): Our goal is to generate uniform RF transmit magnetic fields at 3T, 7T and 11.74T MRI system using single RF coil. Approach: Based on electromagnetic(EM) simulation, we proposed a new geometry of birdcage coil, which has 6 end-rings and 4 legs for triple resonance frequencies. Results: In EM simulation, the proposed coil showed higher than 90% uniformity in the central axial plane. In bench measurement, proposed coil clearly showed triple resonance frequencies at 123.2, 297.2 and 500MHz. Impact: Our proposed RF coil, named triple tunable birdcage coil, can generate uniform RF transmitted magnetic fields in 3T, 7T and 11.74T MRI systems. Therefore, it can be used for frequency selection in PET/MRI systems.