IBBT-Vision Lab, Department of Physics, University of Antwerp, Belgium, 2610.
Magn Reson Imaging. 2012 Dec;30(10):1512-8. doi: 10.1016/j.mri.2012.04.021. Epub 2012 Jul 21.
Effective denoising is vital for proper analysis and accurate quantitative measurements from magnetic resonance (MR) images. Even though many methods were proposed to denoise MR images, only few deal with the estimation of true signal from MR images acquired with phased-array coils. If the magnitude data from phased array coils are reconstructed as the root sum of squares, in the absence of noise correlations and subsampling, the data is assumed to follow a non central-χ distribution. However, when the k-space is subsampled to increase the acquisition speed (as in GRAPPA like methods), noise becomes spatially varying. In this note, we propose a method to denoise multiple-coil acquired MR images. Both the non central-χ distribution and the spatially varying nature of the noise is taken into account in the proposed method. Experiments were conducted on both simulated and real data sets to validate and to demonstrate the effectiveness of the proposed method.
有效的去噪对于从磁共振（MR）图像中进行适当的分析和准确的定量测量至关重要。尽管已经提出了许多方法来对 MR 图像进行去噪，但只有少数方法能够处理从相控阵线圈获得的真实信号的估计。如果将相控阵线圈的幅度数据重建为均方根和，在没有噪声相关和欠采样的情况下，数据被假定遵循非中心χ分布。然而，当 k 空间被欠采样以提高采集速度（如在 GRAPPA 等方法中）时，噪声会变得空间变化。在本说明中，我们提出了一种用于去噪多线圈采集的 MR 图像的方法。所提出的方法考虑了非中心χ分布和噪声的空间变化性质。在模拟和真实数据集上进行了实验，以验证和演示所提出方法的有效性。
