Combination of signals from array coils using image-based estimation of coil sensitivity profiles
Combination of signals from array coils using image-based estimation of coil sensitivity profiles
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DOI：
10.1002/mrm.10092
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发表时间：
2002-03-01
影响因子：
3.3
通讯作者：
Hajnal, JV
中科院分区：
文献类型：
--
作者：
Bydder, M;Larkman, DJ;Hajnal, JV
众所周知，组合来自阵列线圈的联合收割机图像数据的最佳无偏方式是线圈信号的逐像素和，其中每个信号由像素位置处的单独线圈灵敏度加权。一种实用的替代方案将来自线圈的图像组合为平方和（SOS）的平方根，这可以降低信噪比（SNR）并引入偏差。这项工作描述了如何通过图像导出的量来替换线圈灵敏度，该图像导出的量使得接近最佳信号组合达到全局强度缩放。典型的缩放是通过单个线圈灵敏度或阵列中的一些或所有线圈的灵敏度的线性或SOS组合。该方法减小了信号偏差，提高了线圈具有不相等噪声水平时的SNR，并且可以减少图像伪影。它可以产生相位校正的数据，从而完全消除偏差。此外，该方法允许来自包括高度局部化线圈的阵列的图像，例如前列腺线圈和外部骨盆阵列，与接近最佳的SNR和强度调制相结合，使它们更容易查看。(C)2002 Wiley-Liss，Inc.
It is well established that the optimal unbiased way to combine image data from array coils is a pixel-by-pixel sum of coil signals, with each signal weighted by the individual coil sensitivity at the location of the pixel. A pragmatic alternative combines the images from the coils as the square root of the sum of squares (SOS), which can reduce the signal-to-noise ratio (SNR) and introduce bias. This work describes how to replace coil sensitivity by an image-derived quantity that enables close to optimal signal combination up to a global intensity scaling. Typical scaling is by an individual coil sensitivity or a linear or SOS combination of the sensitivities of some or all of the coils in the array. The method decreases signal bias, improves SNR when coils have unequal noise levels, and can reduce image artifacts. It can produce phase-corrected data, which eliminates bias completely. In addition, the method allows images from arrays that include highly localized coils, such as a prostate coil and external pelvic array, to be combined with near-optimal SNR and an intensity modulation that makes them easier to view. (C) 2002 Wiley-Liss, Inc.