Chu Ying-Hua, Hsu Yi-Cheng, Keil Boris, Kuo Wen-Jui, Lin Fa-Hsuan
Institute of Biomedical Engineering, National Taiwan University, Taipei, Taiwan.
Athinoula A. Martinos Center for Biomedical Imaging, Massachusetts General Hospital, Charlestown, MA, United States of America.
PLoS One. 2016 Feb 24;11(2):e0149446. doi: 10.1371/journal.pone.0149446. eCollection 2016.
The goal of this study is to optimize a 32-channel head coil array for accelerated 3T human brain proton MRI using either a Cartesian or a radial k-space trajectory. Coils had curved trapezoidal shapes and were arranged in a circular symmetry (CS) geometry. Coils were optimally overlapped to reduce mutual inductance. Low-noise pre-amplifiers were used to further decouple between coils. The SNR and noise amplification in accelerated imaging were compared to results from a head coil array with a soccer-ball (SB) geometry. The maximal SNR in the CS array was about 120% (1070 vs. 892) and 62% (303 vs. 488) of the SB array at the periphery and the center of the FOV on a transverse plane, respectively. In one-dimensional 4-fold acceleration, the CS array has higher averaged SNR than the SB array across the whole FOV. Compared to the SB array, the CS array has a smaller g-factor at head periphery in all accelerated acquisitions. Reconstructed images using a radial k-space trajectory show that the CS array has a smaller error than the SB array in 2- to 5-fold accelerations.
本研究的目的是优化一个32通道头部线圈阵列，以便使用笛卡尔或径向k空间轨迹来加速3T人体脑部质子MRI。线圈呈弯曲梯形形状，并以圆对称（CS）几何结构排列。线圈进行了最佳重叠以降低互感。使用低噪声前置放大器进一步使线圈之间去耦。将加速成像中的信噪比（SNR）和噪声放大与具有足球（SB）几何结构的头部线圈阵列的结果进行比较。在横断面上，CS阵列在视野（FOV）周边和中心处的最大SNR分别约为SB阵列的120%（1070对892）和62%（303对488）。在一维4倍加速中，CS阵列在整个FOV上具有比SB阵列更高的平均SNR。与SB阵列相比，在所有加速采集中，CS阵列在头部周边具有更小的g因子。使用径向k空间轨迹重建的图像表明，在2至5倍加速中，CS阵列比SB阵列具有更小的误差。
