Schmitt Melanie, Potthast Andreas, Sosnovik David E, Polimeni Jonathan R, Wiggins Graham C, Triantafyllou Christina, Wald Lawrence L
Department of Radiology, A.A. Martinos Center for Biomedical Imaging, Massachusetts General Hospital, Charlestown, Massachusetts 02129, USA.
Magn Reson Med. 2008 Jun;59(6):1431-9. doi: 10.1002/mrm.21598.
A 128-channel receive-only array coil is described and tested for cardiac imaging at 3T. The coil is closely contoured to the body with a "clam-shell" geometry with 68 posterior and 60 anterior elements, each 75 mm in diameter, and arranged in a continuous overlapped array of hexagonal symmetry to minimize nearest neighbor coupling. Signal-to-noise ratio (SNR) and noise amplification for parallel imaging (G-factor) were evaluated in phantom and volunteer experiments. These results were compared to those of commercially available 24-channel and 32-channel coils in routine use for cardiac imaging. The in vivo measurements with the 128-channel coil resulted in SNR gains compared to the 24-channel coil (up to 2.2-fold in the apex). The 128- and 32-channel coils showed similar SNR in the heart, likely dominated by the similar element diameters of these coils. The maximum G-factor values were up to seven times better for a seven-fold acceleration factor (R=7) compared to the 24-channel coil and up to two-fold improved compared to the 32-channel coil. The ability of the 128-channel coil to facilitate highly accelerated cardiac imaging was demonstrated in four volunteers using acceleration factors up to seven-fold (R=7) in a single spatial dimension.
描述并测试了一种用于3T心脏成像的128通道仅接收阵列线圈。该线圈采用“蛤壳”几何形状紧密贴合身体，有68个后部元件和60个前部元件，每个元件直径75毫米，以六边形对称的连续重叠阵列排列，以最小化最近邻耦合。在体模和志愿者实验中评估了并行成像的信噪比（SNR）和噪声放大（G因子）。将这些结果与常规用于心脏成像的市售24通道和32通道线圈的结果进行了比较。与24通道线圈相比，使用128通道线圈进行的体内测量导致SNR增加（心尖处高达2.2倍）。128通道和32通道线圈在心脏中显示出相似的SNR，这可能是由这些线圈相似的元件直径主导的。与24通道线圈相比，对于七倍加速因子（R = 7），最大G因子值提高了七倍，与32通道线圈相比提高了两倍。在四名志愿者中，使用高达七倍（R = 7）的加速因子在单个空间维度上证明了128通道线圈促进高度加速心脏成像的能力。
