Snyder C J, DelaBarre L, Metzger G J, van de Moortele P-F, Akgun C, Ugurbil K, Vaughan J T
Radiology, Center for Magnetic Resonance Research, University of Minnesota, Minneapolis, Minnesota 55455-3007, USA.
Magn Reson Med. 2009 Mar;61(3):517-24. doi: 10.1002/mrm.21895.
This work reports preliminary results from the first human cardiac imaging at 7 Tesla (T). Images were acquired using an eight-channel transmission line (TEM) array together with local B(1) shimming. The TEM array consisted of anterior and posterior plates closely positioned to the subjects' thorax. The currents in the independent elements of these arrays were phased to promote constructive interference of the complex, short wavelength radio frequency field over the entire heart. Anatomic and functional images were acquired within a single breath hold to reduce respiratory motion artifacts while a vector cardiogram (VCG) was used to mitigate cardiac motion artifacts and gating. SAR exposure was modeled, monitored, and was limited to FDA guidelines for the human torso in subject studies. Preliminary results including short-axis and four-chamber VCG-retrogated FLASH cines, as well as, short-axis TSE images demonstrate the feasibility of safe and accurate human cardiac imaging at 7T.
这项工作报告了7特斯拉（T）下首次人体心脏成像的初步结果。使用八通道传输线（TEM）阵列结合局部B(1)匀场来采集图像。TEM阵列由前后板组成，紧密贴合受试者胸部。这些阵列独立元件中的电流进行了相位调整，以促进复杂短波长射频场在整个心脏上的相长干涉。在单次屏气期间采集解剖和功能图像，以减少呼吸运动伪影，同时使用矢量心电图（VCG）来减轻心脏运动伪影并进行门控。在受试者研究中，对比吸收率（SAR）暴露进行了建模、监测，并限制在FDA针对人体躯干的指导方针范围内。初步结果包括短轴和四腔心VCG门控的快速低角度激发（FLASH）电影图像，以及短轴快速自旋回波（TSE）图像，证明了在7T下进行安全、准确的人体心脏成像的可行性。
