A 32-channel lattice transmission line array for parallel transmit and receive MRI at 7 tesla.
Transmit and receive RF coil arrays have proven to be particularly beneficial for ultra-high-field MR. Transmit coil arrays enable such techniques as B(1) (+) shimming to substantially improve transmit B(1) homogeneity compared to conventional volume coil designs, and receive coil arrays offer enhanced parallel imaging performance and SNR. Concentric coil arrangements hold promise for developing transceiver arrays incorporating large numbers of coil elements. At magnetic field strengths of 7 tesla and higher where the Larmor frequencies of interest can exceed 300 MHz, the coil array design must also overcome the problem of the coil conductor length approaching the RF wavelength. In this study, a novel concentric arrangement of resonance elements built from capacitively-shortened half-wavelength transmission lines is presented. This approach was utilized to construct an array with whole-brain coverage using 16 transceiver elements and 16 receive-only elements, resulting in a coil with a total of 16 transmit and 32 receive channels.
Center for Magnetic Resonance Research, Department of Radiology, School of Medicine, University of Minnesota, Minneapolis, Minnesota 55455, USA. gregor@cmrr.umn.edu
Gregor
G
Adriany
Edward J
EJ
Auerbach
Carl J
CJ
Snyder
Ark
A
Gözübüyük
Steen
S
Moeller
Johannes
J
Ritter
Pierre-François
PF
Van de Moortele
Tommy
T
Vaughan
Kâmil
K
Uğurbil
D007089:Image Enhancement / Q000295:instrumentation / Q000379:methods; D008279:Magnetic Resonance Imaging / Q000145:classification / Q000295:instrumentation / Q000379:methods*; D019047:Phantoms, Imaging