Effects of k-space filtering and image interpolation on image fidelity in 1H MRSI
Effects of k-space filtering and image interpolation on image fidelity in 1H MRSI
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DOI：
10.1016/s0730-725x(01)00456-8
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发表时间：
2001-11-01
影响因子：
2.5
通讯作者：
Ekholm, S
中科院分区：
文献类型：
--
作者：
Vikhoff-Baaz, B;Starck, G;Ekholm, S
由于k空间采样的截断，二维MRSI受到空间响应函数的影响。K空间数据集的滤波通常用于抑制由SRF效应引起的旁瓣，其中采样的数据集在逆FT之前与加权函数相乘。核磁共振成像中常用的滤波器有余弦滤波器、哈明滤波器和汉明滤波器。通常将数据集内插到更大的图像矩阵中进行分析，其中傅立叶插值法(FOI)和三次样条插值法(CSPI)是两种常用的方法。本文考察了k空间滤波在实际应用中的效果，并比较了两种内插方法对物体的图像表示，结果表明，滤波的应用改善了物体内部结构的图像表示，应该在磁共振成像中使用。FOI正确地显示了数据集中固有的信息，而对象的特征依赖于对象在CSPI内插图像中相对于原始矩阵的位置。因此，应使用FOI对MRSI图像进行定量评估。(C)2001 Elsevier Science Inc.保留所有权利。
2D MRSI suffers from the effect of the spatial response function due to the truncation of the sampling of k-space. Filtering of the k-space data-set is often used to suppress the side lobes caused by the effects of the SRF, where the sampled data-set is multiplied with a weighting function before inverse FT. Commonly used filters in MRSI are the cosine, Harming and Hamming filters. The data-set is often interpolated into a larger image matrix size for analysis, where "Fourier interpolation" (FoI) and "cubic spline interpolation" (CSpI) are two common methods. In this work, the effects of k-space filtering in practical usage was examined, and the image representations of the object for the two interpolation methods were compared.This study showed that application of filtering improves the image representation of the structures in the object and should be used in MRSI. FoI correctly visualizes the information inherent in the data-set, while the features of the object were dependent on the position of the object relative the original matrix in the CSpI interpolated images. FoI should therefore be used for quantitative evaluation of MRSI images. (C) 2001 Elsevier Science Inc. All rights reserved.