The availability of digital twins for the cardiovascular system will enable insightful computational tools both for research and clinical practice. This, however, demands robust and well defined methods for the different steps involved in the process. We present a vessel coordinate system (VCS) that enables the unanbiguous definition of locations in a vessel section, by adapting the idea of cylindrical coordinates to the vessel geometry. Using the VCS, point correspondence can be defined among different samples of a cohort, allowing data transfer, quantitative comparison, shape coregistration or population analysis. We provide the technical details for coordinates computation and discuss the assumptions taken to guarantee that they are well defined. The VCS is tested in a series of applications. We present a robust, low dimensional, patient specific vascular model and use it to study phenotype variability analysis of the thoracic aorta within a cohort of patients. Point correspondence is exploited to build an haemodynamics atlas of the aorta for the same cohort. Across the paper, we also show how VCS can be used for visualization of different types of data on the anatomy.

翻译：心血管系统数字孪生的可用性将为研究与临床实践提供深刻的计算工具。然而，这要求该过程中各步骤具备稳健且定义明确的方法。我们提出一种血管坐标系 (VCS)，通过将柱坐标概念适配至血管几何结构，实现血管截面上位置的无歧义定义。利用VCS，可在队列的不同样本间建立点的对应关系，从而支持数据迁移、定量比较、形状共配准或群体分析。我们提供坐标计算的技术细节，并讨论确保其定义良好的假设条件。VCS在系列应用中得到验证：我们提出一种稳健的低维患者特异性血管模型，并用于研究胸主动脉在患者队列中的表型变异性分析；同时利用点对应关系为同一队列构建主动脉血液动力学图谱。在全文范围内，我们还展示VCS如何用于解剖结构上不同类型数据的可视化。