论文标题
区域几何和功能评估的右心室容量
Volumetric parcellation of the right ventricle for regional geometric and functional assessment
论文作者
论文摘要
3D超声心动图是一种越来越流行的工具,用于评估右心室(RV)中的心脏重塑。它允许在没有任何几何假设的情况下定量心脏室,这是2D超声心动图的主要弱点。然而,几何和功能的区域量化受到较低的空间和时间分辨率以及可识别的解剖学地标的稀缺性的限制。我们开发了一种用于评估3个相关RV区域的技术:顶,入口和流出。该方法的输入是末期 - 舒张(ED)和末端节局(ES)分割的3D表面模型。该方法首先使用从每个表面点到顶点,三尖瓣和肺动脉瓣的大地距离的距离定义了ED内膜的分区:定义了3个区域的地标。然后将ED表面网格四面体化,心内膜定义的分区通过拉普拉斯方程在血液腔中插值。为了获得ES分区,使用基于图像的跟踪将心内膜分区从ED转移到ES,然后插入与ED类似的心内膜插入,以计算体积和射血分数(EF)。我们对该方法的有效性和可重复性进行了完整的评估。首先,我们评估在分割变异性下的可重复性,获得了观察者内部和间间误差(分别为4-10%和10-23%)。最后,我们使用合成重塑数据集来确定我们方法能够正确确定已重塑区域的情况。该数据集是通过一种新型的网格重建方法生成的,该方法变形了参考网格,该方法在解剖坐标中表达的局部施加给定菌株。我们表明,分析方法足以捕获局部圆周和全球圆周和纵向RV重塑。
3D echocardiography is an increasingly popular tool for assessing cardiac remodelling in the right ventricle (RV). It allows quantification of the cardiac chambers without any geometric assumptions, which is the main weakness of 2D echocardiography. However, regional quantification of geometry and function is limited by the lower spatial and temporal resolution and the scarcity of identifiable anatomical landmarks. We developed a technique for regionally assessing the 3 relevant RV regions: apical, inlet and outflow. The method's inputs are end-diastolic (ED) and end-systolic (ES) segmented 3D surface models. The method first defines a partition of the ED endocardium using the geodesic distances from each surface point to apex, tricuspid valve and pulmonary valve: the landmarks that define the 3 regions. The ED surface mesh is then tetrahedralised, and the endocardial-defined partition is interpolated in the blood cavity via the Laplace equation. For obtaining an ES partition, the endocardial partition is transported from ED to ES using a commercial image-based tracking, and then interpolated towards the endocardium, similarly to ED, for computing volumes and ejection fraction (EF). We present a full assessment of the method's validity and reproducibility. First, we assess reproducibility under segmentation variability, obtaining intra- and inter- observer errors (4-10% and 10-23% resp.). Finally, we use a synthetic remodelling dataset to identify the situations in which our method is able to correctly determine the region that has remodelled. This dataset is generated by a novel mesh reconstruction method that deforms a reference mesh, locally imposing a given strain, expressed in anatomical coordinates. We show that the parcellation method is adequate for capturing local circumferential and global circumferential and longitudinal RV remodelling.