Melbourne Neuropsychiatry Centre, Department of Psychiatry, The University of Melbourne and Melbourne Health, Victoria 3010, Australia.
Magn Reson Imaging. 2011 Jan;29(1):111-25. doi: 10.1016/j.mri.2010.06.027. Epub 2010 Oct 8.
An evaluative methodology and five accompanying performance measures were developed to quantitatively assess the performance of the skeleton projection algorithm constituting the heart of tract-based spatial statistics (TBSS). The performance measures were designed to quantify the accuracy of skeleton projection in its indented task of alleviating any residual misalignment that may remain after image registration. A ground truth fractional anisotropy (FA) image was slightly warped using a realistic warp field that served to model post-registration residual misalignment of varying magnitudes. Skeleton projection was then used to register the warped FA image to the ground truth. Performing skeleton projection was found to yield up to 50% better correspondence between the values of FA compared to smoothing, despite the fact that less than 10% of post-registration misalignment was corrected. The align-max-with-max strategy underlying TBSS was posited as a potential explanation for this high correspondence in the values of FA, at the expense of lesser alignment between anatomically concordant voxels.
开发了一种评估方法和五个配套的性能指标，以定量评估构成基于轨迹的空间统计学（TBSS）核心的骨架投影算法的性能。这些性能指标旨在量化骨架投影在减轻图像配准后可能残留的任何残余不对齐方面的准确性。使用真实的变形场轻微变形了一个真实的各向异性分数（FA）图像，该变形场用于对不同大小的配准后残余不对齐进行建模。然后使用骨架投影将变形的 FA 图像配准到真实图像。尽管只纠正了不到 10%的配准后不对齐，但与平滑处理相比，执行骨架投影可以使 FA 值之间的一致性提高多达 50%。TBSS 所基于的“对齐最大值与最大值”策略被认为是 FA 值之间这种高度一致性的潜在解释，这是以牺牲解剖学一致体素之间的较小对齐为代价的。
