Designing novel radio-frequency coils for high field and ultra-high field magnetic resonance imaging

2021 Fall.Includes bibliographical references.High field and ultra-high field magnetic resonance imaging is the upcoming technology in the field of magnetic resonance imaging. This has created the need for designing of new radio frequency (RF) coils. Here are presented several of these novel RF coils include multifilar helical antenna coils for 3-T, 4.7-T, 7-T and 10.5-T NMR scanners, slotted-waveguide array coils for 7-T, inverted microstrip array coil for 7-T along with other methods to improve the efficiency and homogeneity of the RF field. The coils were simulated using commercial electromagnetic solvers including WIPL-D and ANSYS-HFSS, and some were also measured experimentally. The results for B1+ efficiency are compared with state-of-art coils. These novel coils exhibit high B1+ efficiency, strong right-hand polarization, good field homogeneity with an acceptable level of SAR. Details of numerical methods for the simulations of the coils has also been discussed. Ongoing work and future plans have also been presented