Bhalodia Riddhish, Subramanian Archanasri, Morris Alan, Cates Joshua, Whitaker Ross, Kholmovski Evgueni, Marrouche Nassir, Elhabian Shireen
Scientific Computing and Imaging Institute, University of Utah, Salt Lake City, Utah, USA.
Division of Cardiovascular Medicine, School of Medicine, University of Utah, Salt Lake City, Utah, USA.
Comput Cardiol (2010). 2019;46. doi: 10.22489/cinc.2019.200. Epub 2020 Feb 24.
Evidence suggests that the shape of left atrium appendages (LAA) is a primary indicator in predicting stroke for patients diagnosed with atrial fibrillation (AF). Statistical shape modeling tools used to represent (i.e., parameterize) the underlying LAA variability are of crucial importance to learn shape-based predictors of stroke. Most shape modeling techniques use some form of alignment either as a data pre-processing step or during the modeling step. However, the LAA is a joint anatomy along with left atrium (LA), and the relative position and alignment plays a crucial part in determining risk of stroke. In this paper, we explore different alignment strategies for statistical shape modeling and how each strategy affects the stroke prediction capability. This allows for identifying a unified approach of alignment while analyzing the LAA anatomy for stroke. Here, we study three different alignment strategies, (i) global alignment, (ii) global translational alignment and (iii) cluster based alignment. Our results show that alignment strategies that take into account LAA orientation, i.e., (ii), or the inherent natural clustering of the population under study, i.e., (iii), provide significant improvement over global alignment in both qualitative as well as quantitative measures.
有证据表明，左心耳（LAA）的形状是预测被诊断为房颤（AF）患者中风的主要指标。用于表示（即参数化）潜在的左心耳变异性的统计形状建模工具对于了解基于形状的中风预测因素至关重要。大多数形状建模技术在数据预处理步骤或建模步骤中使用某种形式的对齐。然而，左心耳是与左心房（LA）相连的联合解剖结构，其相对位置和对齐在确定中风风险中起着关键作用。在本文中，我们探索了用于统计形状建模的不同对齐策略以及每种策略如何影响中风预测能力。这使得在分析用于中风的左心耳解剖结构时能够确定一种统一的对齐方法。在此，我们研究了三种不同的对齐策略：（i）全局对齐、（ii）全局平移对齐和（iii）基于聚类的对齐。我们的结果表明，考虑左心耳方向的对齐策略，即（ii），或所研究人群的固有自然聚类，即（iii），在定性和定量测量方面都比全局对齐有显著改进。
