Heo P, Seo JH, Han SD, Ryu Y, Byun JD, Kim KN, Lee JH. Multi-port-driven birdcage coil for multiple-mouse MR imaging at 7 T.
SCANNING 2016;
38:747-756. [PMID:
27162104 DOI:
10.1002/sca.21324]
[Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/19/2016] [Accepted: 04/19/2016] [Indexed: 06/05/2023]
Abstract
In ultra-high field (UHF) imaging environments, it has been demonstrated that multiple-mouse magnetic resonance imaging (MM-MRI) is dependent on key factors such as the radiofrequency (RF) coil hardware, imaging protocol, and experimental setup for obtaining high-resolution MR images. A key aspect is the RF coil, and a number of MM-MRI studies have investigated the application of single-channel RF transmit (Tx)/receive (Rx) coils or multi-channel phased array (PA) coil configurations under a single gradient coil set. However, despite applying a variety of RF coils, Tx (|B1+ |)-field inhomogeneity still remains a major problem due to the relative shortening of the effective RF wavelength in the UHF environment. To address this issue, we propose a relatively smaller size of individual Tx-only coils in a multiple birdcage (MBC) coil for MM-MRI to image up to three mice. We use electromagnetic (EM) simulations in the finite-difference time-domain (FDTD) environment to obtain the |B1 |-field distribution. Our results clearly show that the single birdcage (SBC) high-pass filter (HPF) configuration, which is referred to as the SBCHPF , under the absence of an RF shield exhibits a high |B1 |-field intensity in comparison with other coil configurations such as the low-pass filter (LPF) and band-pass filter (BPF) configurations. In a 7-T MRI experiment, the signal-to-noise ratio (SNR) map of the SBCHPF configuration shows the highest coil performance compared to other coil configurations. The MBCHPF coil, which is comprised of a triple-SBCHPF configuration combined with additional decoupling techniques, is developed for simultaneous image acquisition of three mice. SCANNING 38:747-756, 2016. © 2016 Wiley Periodicals, Inc.
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