Discussion of LESA: Longitudinal Elastic Shape Analysis of Brain Subcortical Structures
Discussion of LESA: Longitudinal Elastic Shape Analysis of Brain Subcortical Structures
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LESA的讨论:大脑皮层下结构的纵向弹性形状分析
DOI:
10.1080/01621459.2022.2120399
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发表时间:
2023
影响因子:
3.7
通讯作者:
Lila, Eardi
中科院分区:
文献类型:
--
作者:
Aston, John A.;Lila, Eardi
We congratulate the authors on an interesting paper which combines the ideas of shape analysis with longitudinal data analysis. With the increasing complexity of experiments involving imaging data, including a number of important longitudinal imaging studies, not least those presented, it is important to develop methodology that allows for a considered analysis of such data, and this article goes a long way to helping address these issues.There are a number of important choices made in the paper. The registration of the shapes themselves is done through an approach which first received prominence in a statistical functional data context in Srivastava et al.(2011), where the squareroot velocity function plays an analogous role to the squareroot normal field (SRNF)(Jermyn et al. 2012). This approach has highly beneficial properties that allow for the definition of reparameterization invariant metrics as described for the SNRF approach in this article. It is very interesting to see the approach using mixed-effect models which again has connections to the literature in functional data and registration (Tucker, Wu, and Srivastava 2013; Hadjipantelis et al. 2015; Marron et al. 2015). However, as with many instances of longitudinal data analysis, particularly with sparse observations, it is very natural to consider the temporal components of the data to be a form of functional data, and hence the PACE approach (Yao, Müller, and Wang 2005) is a more suitable framework to model these in. There are many possible extensions to the original PACE idea, and all these could be implemented if relevant to the application. Of course, this would also set up a number of challenging theoretical questions, particularly given the non-Euclidean nature of shape spaces.