Chen C N, Sank V J, Cohen S M, Hoult D I
Magn Reson Med. 1986 Oct;3(5):722-9. doi: 10.1002/mrm.1910030508.
A method is proposed for measuring on the bench the NMR signal-to-noise ratio of rf probes, (over the range 1-100 MHz) and also the power deposited in patients during the imaging experiment. The technique is based on the principle of reciprocity, in that a direct relationship exists between the magnetic field generated (upon transmission) by a matched probe coil and the signal-to-noise ratio delivered by the same coil when used as a receiver. The construction and use of a calibrated sense coil for measuring the field is described, and the precautions and theory necessary for accurate measurement and understanding are outlined. Finally, the method is verified by comparison with a direct spectral measure of sensitivity obtained from a small doped water sample placed in NMR imaging equipment.
本文提出了一种在工作台上测量射频探头的核磁共振信噪比（在1 - 100兆赫范围内）以及成像实验期间患者体内沉积功率的方法。该技术基于互易原理，即匹配探头线圈（发射时）产生的磁场与同一线圈用作接收器时的信噪比之间存在直接关系。描述了用于测量磁场的校准感应线圈的构造和使用方法，并概述了准确测量和理解所需的注意事项和理论。最后，通过与放置在核磁共振成像设备中的小掺杂水样获得的灵敏度直接光谱测量结果进行比较，验证了该方法。
