High-density dipole array for human lumbar spine cord imaging at 7T

The Dipole antenna, which has a long longitudinal coverage and deep penetration, has demonstrated a better transmit efficiency for spinal cord imaging compared to the standard loop coil. However, owing to the inevitable coupling, the number of dipoles is highly limited. In this work, we find that the number of dipoles could be doubled if they are be shortened in different ways and arranged to interleave. An 8-channel dipole array consisting of 4 inductor-shortened dipoles and 4 folded dipoles was designed and numerically investigated for 7T lumbar spinal cord imaging.