Fujita Hiroyuki
Department of Physics, Case Western Reserve University, Cleveland, OH 44106, USA.
Magn Reson Med Sci. 2007;6(1):29-42. doi: 10.2463/mrms.6.29.
Parallel imaging techniques have developed very rapidly, and realization of their full potential has required the design of magnetic resonance (MR) scanners with ever-increasing numbers of receiver channels (32 to 128). In particular, 1.5- and 3-Tesla fast MR imaging applications are now used in everyday clinical practice. Both strengths require maximum achievable signal-to-noise ratio (SNR) and multi-detector array coil optimization within the framework of the parallel imaging scheme for more advanced and faster clinical MR scanning. Preamplifiers are key components in the detector array coils and serve many functions beyond mere signal amplification. One critical function is to aid in the decoupling of individual coils, which is essential for optimal SNR and the performance of parallel imaging. To support a large number of detector array coils for parallel imaging, preamplifiers must be physically very small so that they may be tightly packed together to form an optimized detector array. The author herein reviews the state-of-the-art work reported by those skilled in the art to consider the rationale for determining how many channels are enough and how fast we can go. The paper explores the important and fundamental principles of RF array coils for MR imaging and reviews cutting-edge array coils, including those for transmit-SENSE or parallel transmission applications. The future of radiofrequency (RF) coil technology is also considered.
并行成像技术发展非常迅速，要充分发挥其潜力，需要设计接收通道数量不断增加（32至128个）的磁共振（MR）扫描仪。特别是，1.5特斯拉和3特斯拉的快速MR成像应用如今已用于日常临床实践。这两种场强都要求在并行成像方案的框架内实现最大可达到的信噪比（SNR）以及多探测器阵列线圈的优化，以进行更先进、更快的临床MR扫描。前置放大器是探测器阵列线圈中的关键组件，其作用远不止于单纯的信号放大。一个关键功能是有助于单个线圈的去耦，这对于实现最佳SNR和平行成像性能至关重要。为了支持用于并行成像的大量探测器阵列线圈，前置放大器必须在物理尺寸上非常小，以便它们可以紧密排列在一起，形成一个优化的探测器阵列。本文作者回顾了本领域技术人员所报道的最新研究成果，以探讨确定通道数量足够以及速度能有多快的基本原理。本文探讨了用于MR成像的射频阵列线圈的重要基本原理，并回顾了前沿的阵列线圈，包括用于发射敏感编码（transmit-SENSE）或并行发射应用的线圈。还考虑了射频（RF）线圈技术的未来发展。
