Avdievich Nikolai I, Peshkovsky Alexey S, Kennan Richard P, Hetherington Hoby P
Department of Radiology, Albert Einstein College of Medicine, Bronx, New York 10461, USA.
J Magn Reson Imaging. 2006 Oct;24(4):934-8. doi: 10.1002/jmri.20714.
To demonstrate the feasibility of high-field SENSE imaging of large objects, such as the human head, using a semicircular (half-volume) coil for both transmission and multi-channel reception.
As a proof of concept, we present experimental data obtained using a seven-element half-volume (180 degrees of arc) transmit/receive quadrature transverse electromagnetic (TEM) coil. SENSE images of the human brain were acquired with a reduction factor of R=2, using two degenerate linear modes of the same coil as independent receive channels at 4T. Since the need for additional hardware (i.e., a separate set of receive coils) is eliminated, the design can be substantially simplified.
The experimental data demonstrate that linear modes of the half-volume TEM coil have essentially no noise correlation, and their sensitivity profiles satisfy the requirement for small g-factors. Also, this type of coil provides efficient transmission with a relatively large uniform region and a reception profile that is more uniform than that of the surface coils.
We demonstrate the feasibility of SENSE imaging using a half-volume coil. Half-volume coils allow reduced total power deposition compared to full-volume coils, and may replace the latter in body imaging applications in which the target region of interest (ROI) is smaller than the entire torso.
利用半圆形（半容积）线圈进行发射和多通道接收，以证明对大型物体（如人类头部）进行高场敏感编码成像（SENSE成像）的可行性。
作为概念验证，我们展示了使用七元半容积（180度弧）发射/接收正交横向电磁（TEM）线圈获得的实验数据。在4T场强下，使用同一线圈的两种简并线性模式作为独立接收通道，以R = 2的缩减因子采集人脑的SENSE图像。由于无需额外硬件（即单独的一组接收线圈），该设计可大幅简化。
实验数据表明，半容积TEM线圈的线性模式基本没有噪声相关性，其灵敏度分布满足小g因子的要求。此外，这种类型的线圈能实现高效发射，具有相对较大的均匀区域，且接收分布比表面线圈更均匀。
我们证明了使用半容积线圈进行SENSE成像的可行性。与全容积线圈相比，半容积线圈可降低总功率沉积，在感兴趣的目标区域（ROI）小于整个躯干的身体成像应用中，可能会取代全容积线圈。
