A local multi-transmit coil combined with a high-density receive array for cerebellar fMRI at 7 T

TY - JOUR

T1 - A local multi-transmit coil combined with a high-density receive array for cerebellar fMRI at 7 T

AU - Priovoulos, Nikos

AU - Roos, Thomas

AU - Ipek, Özlem

AU - Meliado, Ettore F

AU - Nkrumah, Richard O

AU - Klomp, Dennis W J

AU - van der Zwaag, Wietske

N1 - © 2021 The Authors. NMR in Biomedicine published by John Wiley & Sons Ltd.

PY - 2021/7/6

Y1 - 2021/7/6

N2 - The human cerebellum is involved in a wide array of functions, ranging from motor control to cognitive control, and as such is of great neuroscientific interest. However, its function is underexplored in vivo, due to its small size, its dense structure and its placement at the bottom of the brain, where transmit and receive fields are suboptimal. In this study, we combined two dense coil arrays of 16 small surface receive elements each with a transmit array of three antenna elements to improve BOLD sensitivity in the human cerebellum at 7 T. Our results showed improved B1 + and SNR close to the surface as well as g-factor gains compared with a commercial coil designed for whole-head imaging. This resulted in improved signal stability and large gains in the spatial extent of the activation close to the surface (<3.5 cm), while good performance was retained deeper in the cerebellum. Modulating the phase of the transmit elements of the head coil to constructively interfere in the cerebellum improved the B1 + , resulting in a temporal SNR gain. Overall, our results show that a dedicated transmit array along with the SNR gains of surface coil arrays can improve cerebellar imaging, at the cost of a decreased field of view and increased signal inhomogeneity.

AB - The human cerebellum is involved in a wide array of functions, ranging from motor control to cognitive control, and as such is of great neuroscientific interest. However, its function is underexplored in vivo, due to its small size, its dense structure and its placement at the bottom of the brain, where transmit and receive fields are suboptimal. In this study, we combined two dense coil arrays of 16 small surface receive elements each with a transmit array of three antenna elements to improve BOLD sensitivity in the human cerebellum at 7 T. Our results showed improved B1 + and SNR close to the surface as well as g-factor gains compared with a commercial coil designed for whole-head imaging. This resulted in improved signal stability and large gains in the spatial extent of the activation close to the surface (<3.5 cm), while good performance was retained deeper in the cerebellum. Modulating the phase of the transmit elements of the head coil to constructively interfere in the cerebellum improved the B1 + , resulting in a temporal SNR gain. Overall, our results show that a dedicated transmit array along with the SNR gains of surface coil arrays can improve cerebellar imaging, at the cost of a decreased field of view and increased signal inhomogeneity.

U2 - 10.1002/nbm.4586

DO - 10.1002/nbm.4586

M3 - Article

C2 - 34231292

SN - 0952-3480

VL - 34

SP - e4586

JO - NMR in Biomedicine

JF - NMR in Biomedicine

ER -