Modified petal resonator surface coil for UHF-MRI

In this paper, a modified radio frequency (RF) coil version is presented to be suitable to work at 900 MHz. The proposed coil is based on the Petal Surface Coil and Petal Resonator Surface Coil, whose resonant frequencies were 22 MHz and 64 MHz, respectively. These encouraging results at low field motivated the development of a modified petal resonator surface coil for ultra-high field magnetic resonance imaging applications. Electromagnetic field and return loss simulations guided the development of our coil design. Our prototype consisted of six small circular loops whose diameter was 0.5 cm, connected in series and the total coil diameter was 3 cm. Electromagnetic simulations showed the characteristic patterns of the prototype and provided the theoretical grounds to reliably develop this type of RF coils at 900 MHz. Bench tests measurements showed an important agreement with numerical values. It still remains to actually acquire phantom images to test the viability and compatibility with standard procedures for ultra-high field magnetic resonance imaging applications. This coil design may serve to develop coil arrays with improved performance for high frequencies.