Christopher P. Bidinosti1, Chen-Yi Liu1,
Scott B. King2
1Physics,
Spiral
birdcage coils have been used for transmit array spatial encoding (TRASE) as
well as for partially correcting central image brightening. A Fourier
transform method usually employed for designing wire-wound shim, gradient and
low frequency RF coils is used here to analyze the magnetic field symmetries
of the spiral birdcage coil. Results
show that twisting leads to a strong, intrinsic radial dependence in all
magnetic field components. This knowledge will guide the optimization of
coils used for TRASE, and may also lead to a more direct correction scheme
for the problem of central brightening that occurs in high field MRI.
Keywords