Enhancing the multivariate signal of [/sup 15/O] water PET studies with a new nonlinear neuroanatomical registration algorithm [MRI application]
Enhancing the multivariate signal of [/sup 15/O] water PET studies with a new nonlinear neuroanatomical registration algorithm [MRI application]
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发表时间：
1999
影响因子：
10.6
通讯作者：
U. Kjems;S. Strother;J. Anderson;I. Law;L. K. Hansen
中科院分区：
文献类型：
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作者：
U. Kjems;S. Strother;J. Anderson;I. Law;L. K. Hansen
本文讨论了功能性[/sup 15/O]水PET激活研究中个体间神经解剖配准的问题。提出了一种新的MR扫描三维非线性结构配准算法。该方法执行一个分层缩放搜索的位移场，最大化的几个体素相似性措施之一，从二维（2-D）直方图匹配的图像强度，正则化，确保位移场的平滑。研究了在解剖MR扫描上计算非线性结构配准的效果，并将其应用于来自相同受试者的共配准[/sup 15/O]水PET扫描：在本实验中，研究了视觉引导的扫视眼球运动。使用多变量函数信号和噪声措施的非线性翘曲的性能进行评估。事实证明，这些措施对于比较不同的受试者间配准方法很有用，例如，仿射与非线性。12参数仿射配准与非线性配准的比较表明，所提出的非线性方法增加了保留在跨主题掩模中的体素的数量。作者证明，改进的结构配准可能导致改进的多元函数信噪比（SNR）。此外，与直接对PET图像进行12参数仿射对准相比，使用对准共同配准的MR图像的12参数仿射变换对PET扫描进行配准不会改善配准。
This paper addresses the problem of neuro-anatomical registration across individuals for functional [/sup 15/O] water PET activation studies. A new algorithm for three-dimensional (3-D) nonlinear structural registration (warping) of MR scans is presented. The method performs a hierarchically scaled search for a displacement field, maximizing one of several voxel similarity measures derived from the two-dimensional (2-D) histogram of matched image intensities, subject to a regularizer that ensures smoothness of the displacement field. The effect of the nonlinear structural registration is studied when it is computed on anatomical MR scans and applied to coregistered [/sup 15/O] water PET scans from the same subjects: in this experiment, a study of visually guided saccadic eye movements. The performance of the nonlinear warp is evaluated using multivariate functional signal and noise measures. These measures prove to be useful for comparing different intersubject registration approaches, e.g., affine versus nonlinear. A comparison of 12-parameter affine registration versus nonlinear registration demonstrates that the proposed nonlinear method increases the number of voxels retained in the cross-subject mask. The authors demonstrate that improved structural registration may result in an improved multivariate functional signal-to-noise ratio (SNR). Furthermore, registration of PET scans using the 12-parameter affine transformations that align the coregistered MR images does not improve registration, compared to 12-parameter affine alignment of the PET images directly.