TY - JOUR
T1 - A Monopole and Dipole Hybrid Antenna Array for Human Brain Imaging at 10.5 Tesla
AU - Woo, Myung Kyun
AU - Delabarre, Lance
AU - Waks, Matt
AU - Lagore, Russell
AU - Radder, Jerahmie
AU - Jungst, Steve
AU - Kang, Chang Ki
AU - Ugurbil, Kamil
AU - Adriany, Gregor
N1 - Publisher Copyright:
© 2002-2011 IEEE.
PY - 2022/9/1
Y1 - 2022/9/1
N2 - In this letter, we evaluate antenna designs for ultra-high frequency and field (UHF) human brain magnetic resonance imaging (MRI) at 10.5 tesla (T). Although MRI at such UHF is expected to provide major signal-to-noise gains, the frequency of interest, 447 MHz, presents us with challenges regarding improved B1+ efficiency, image homogeneity, specific absorption rate (SAR), and antenna element decoupling for array configurations. To address these challenges, we propose the use of both monopole and dipole antennas in a novel hybrid configuration, which we refer to as a mono-dipole hybrid antenna (MDH) array. Compared to an 8-channel dipole antenna array of the same dimensions, the 8-channel MDH array showed an improvement in decoupling between adjacent array channels, as well as ∼18% higher B1+ and SAR efficiency near the central region of the phantom based on simulation and experiment. However, the performances of the MDH and dipole antenna arrays were overall similar when evaluating a human model in terms of peak B1+ efficiency, 10 g SAR, and SAR efficiency. Finally, the concept of an MDH array showed an advantage in improved decoupling, SAR, and B1+ near the superior region of the brain for human brain imaging.
AB - In this letter, we evaluate antenna designs for ultra-high frequency and field (UHF) human brain magnetic resonance imaging (MRI) at 10.5 tesla (T). Although MRI at such UHF is expected to provide major signal-to-noise gains, the frequency of interest, 447 MHz, presents us with challenges regarding improved B1+ efficiency, image homogeneity, specific absorption rate (SAR), and antenna element decoupling for array configurations. To address these challenges, we propose the use of both monopole and dipole antennas in a novel hybrid configuration, which we refer to as a mono-dipole hybrid antenna (MDH) array. Compared to an 8-channel dipole antenna array of the same dimensions, the 8-channel MDH array showed an improvement in decoupling between adjacent array channels, as well as ∼18% higher B1+ and SAR efficiency near the central region of the phantom based on simulation and experiment. However, the performances of the MDH and dipole antenna arrays were overall similar when evaluating a human model in terms of peak B1+ efficiency, 10 g SAR, and SAR efficiency. Finally, the concept of an MDH array showed an advantage in improved decoupling, SAR, and B1+ near the superior region of the brain for human brain imaging.
KW - Dipole antenna
KW - human brain imaging
KW - monopole antenna
KW - multi-channel array
KW - ultra-high field imaging
UR - https://www.scopus.com/pages/publications/85132739783
UR - https://www.scopus.com/pages/publications/85132739783#tab=citedBy
U2 - 10.1109/LAWP.2022.3183206
DO - 10.1109/LAWP.2022.3183206
M3 - Article
AN - SCOPUS:85132739783
SN - 1536-1225
VL - 21
SP - 1857
EP - 1861
JO - IEEE Antennas and Wireless Propagation Letters
JF - IEEE Antennas and Wireless Propagation Letters
IS - 9
ER -