TY  - JOUR
AU  - Ha, YongHyun
AU  - Choi, Chang-Hoon
AU  - Worthoff, Wieland
AU  - Shymanskaya, Aliaksandra
AU  - Schöneck, Michael
AU  - Willuweit, Antje
AU  - Felder, Jörg
AU  - Shah, N. J.
TI  - Design and use of a folded four-ring double-tuned birdcage coil for rat brain sodium imaging at 9.4 T
JO  - Journal of magnetic resonance
VL  - 286
SN  - 1090-7807
CY  - Amsterdam [u.a.]
PB  - Elsevier
M1  - FZJ-2018-00163
SP  - 110 - 114
PY  - 2018
AB  - A folded four-ring quadrature birdcage coil was designed and constructed with a double-tune configuration of an outer high-pass coil for 1H (400 MHz) and inner low-pass coil for 23Na (105.72 MHz at 9.4 T). The coil was evaluated on the bench and in the scanner, comparing its performance with that of single-tuned coils and a large four-ring coil. All coils were tuned and matched and the isolation between two quadrature ports was found to be better than −13.7 dB for 1H and −27 dB for 23Na. Signal-to-noise ratios (SNRs) were calculated and 23Na flip angle maps were acquired. 23Na SNR of the folded four-ring reached ∼93% of that obtained with the single-tuned coil. A set of in vivo1H and 23Na axial images to cover the whole rat brain were obtained. The performance of the folded four-ring coil and its benefit for 23Na imaging experiments have been demonstrated. This proposed four-ring coil could avoid length restrictions, e.g. the shoulders, by folding the outer rings vertically. This facilitates the construction of double-tuned four-ring birdcage coils just to fit the head, leading to higher filling factors and better SNR.
LB  - PUB:(DE-HGF)16
C6  - pmid:29227914
UR  - <Go to ISI:>//WOS:000424071300015
DO  - DOI:10.1016/j.jmr.2017.12.003
UR  - https://juser.fz-juelich.de/record/841866
ER  -