Wiggins G C, Potthast A, Triantafyllou C, Wiggins C J, Wald L L
Department of Radiology, Massachusetts General Hospital, A. A. Martinos Center, Charlestown, Massachusetts 02129, USA.
Magn Reson Med. 2005 Jul;54(1):235-40. doi: 10.1002/mrm.20547.
An eight-channel receive-only brain coil and table-top detunable volume transmit coil were developed and tested at 7 T for human imaging. Optimization of this device required attention to sources of interaction between the array elements, between the transmit and receive coils and minimization of common mode currents on the coaxial cables. Circular receive coils (85 mm dia.) were designed on a flexible former to fit tightly around the head and within a 270-mm diameter TEM transmit volume coil. In the near cortex, the array provided a fivefold increase in SNR compared to a TEM transmit-receive coil, a gain larger than that seen in comparable coils at 3 T. The higher SNR gain is likely due to strong dielectric effects, which cause the volume coil to perform poorly in the cortex compared to centrally. The sensitivity and coverage of the array is demonstrated with high-resolution images of the brain cortex.
开发了一种八通道仅接收型脑线圈和桌面可调谐容积发射线圈，并在7T场强下进行人体成像测试。该设备的优化需要关注阵列元件之间、发射和接收线圈之间的相互作用源，并尽量减少同轴电缆上的共模电流。圆形接收线圈（直径85mm）设计在柔性框架上，以紧密贴合头部并置于直径270mm的TEM发射容积线圈内。在近皮质区域，与TEM发射-接收线圈相比，该阵列的信噪比提高了五倍，增益大于在3T场强下的同类线圈。更高的信噪比增益可能是由于强烈的介电效应，这导致容积线圈在皮质区域的表现比中心区域差。通过大脑皮质的高分辨率图像展示了该阵列的灵敏度和覆盖范围。
