An algorithm for the optimum combination of data from arbitrary magnetic resonance phased array probes
An algorithm for the optimum combination of data from arbitrary magnetic resonance phased array probes
复制标题
DOI：
10.1088/0031-9155/47/2/402
复制
发表时间：
2002-01-21
影响因子：
3.5
通讯作者：
Leach, MO
中科院分区：
文献类型：
--
作者：
Prock, T;Collins, DJ;Leach, MO
当用分阶段阵列线圈获得的光谱总结时，信号噪声比率低或错误校正相的信号可能会降低总体信号噪声比（SNR）。在这里，我们提出了一个数学表达式，可预测组合SNR对复合信号相位校正中的信噪比和误差的依赖性。基于此方程。可以将信号与噪声比率总体增加的信号从信号的加权总和中排除。该工具对于大量信号的组合特别有用。此外，提出了一种简单而健壮的算法，用于计算光谱数据的信噪比加权组合所需的复杂加权因子。分析了复合光谱之间相对相差的计算和校正中的误差。对于典型的临床磁共振光谱（MRS），这些误差对整体光谱SNR具有可忽略的影响。此处开发的信号组合常规已应用于1.5 t的人类直肠腺癌的第一次体内MRS研究（Dzik-Jurasz A S K，Murphy P S，George P S，George M，Prock T，Collins D J，Collins D J，Swift I和Swift I和Leach M 0 2001 Magn。在媒体上进行复合。
When summing the spectra acquired with phased array coils, signals with low signal-to-noise ratio or wrongly corrected phase may degrade the overall signal-to-noise ratio (SNR). Here we present a mathematical expression predicting the dependence of combined SNR on the signal-to-noise ratios and errors in phase correction of composite signals. Based on this equation., signals that do not lead to an overall increase in signal-to-noise ratio can be identified and excluded from the weighted sum of signals. This tool is particularly useful for the combination of large numbers of signals. Additionally, a simple and robust algorithm for calculating the complex weighting factors necessary for the signal-to-noise weighted combination of spectroscopic data is presented. Errors in the calculation and correction of relative phase differences between composite spectra are analysed. The errors have a negligible effect on the overall spectral SNR for typical clinical magnetic resonance spectroscopy (MRS). The signal combination routine developed here has been applied to the first in vivo MRS study of human rectal adenocarcinomas at 1.5 T (Dzik-Jurasz A S K, Murphy P S, George M, Prock T, Collins D J, Swift I and Leach M 0 2001 Magn. Reson. Med. at press), showing improvements of combined spectral SNR of up to 34% over the maximum SNR from a single element.