IMAGING AND VOLUMETRY IN 3-DIMENSIONAL ECHOCARDIOGRAPHY

这个项目的主要重点是开发和验证一个高度 自动化、临床可行的系统可实现准确的定性(形态学) 和心脏的三维定量(容量测量)评估 超声心动图(3DE)。 这项研究的具体假设是；人体心脏的3DE图像 可以提供更准确的定性和定量信息 目前的二维超声心动图。其目的是测试 以下领域的假设：1)图像获取；使用 经食道入路在两种柱状结构中的获取 (金字塔和圆锥)，找到所需的最佳增量扫描次数 详细的形态学研究和准确的左心室(LV) 卷评估。2)图像分割：提出了一种两步算法 用于三维超声心动图左室抽吸术。第一步包括自动识别 以及确定适合于以下条件的全局阈值 左心室和心脏结构的初始分割。在第二步中， 使用一种先进的空腔边界检测算法来创建3D LV腔的计算机表示。该算法模拟了 自然细胞的自主生长，使其形状适应于 周围的环境。该软件控制着生长和弹性性能 “细胞膜”应再现左心室的空间分布。 心内膜表面。生成的3D对象将用于定性 对左心室进行定量评价。3)临床验证和 应用：3DE左心室容量测量的准确性将通过 该方法与CT容积测量法的比较。病人 随着正常和对称性或不对称性增大，LV将 被选中了。经过验证的3DE算法将随后应用于 缺血性、瓣膜和先天性心脏病患者的研究 在临床超声心动图实验室检查。 该项目的意义在于，可理解的3DE图像 心脏解剖和准确的左心室容量测量将提高心脏手术的质量 心血管疾病患者的诊断、治疗和随访 疾病。

The primary emphasis of this project is to develop and validate a highly automated, clinically feasible system for accurate qualitative (morphology) and quantitative (volumetry) assessment of the heart by 3 dimensional echocardiography (3DE). The specific hypothesis of this research is; 3DE images of the human heart can provide more accurate qualitative and quantitative information than current 2-dimensional echocardiography. The aims are to test the hypothesis in the following areas: 1) Image Acquisition; Using a transesophageal approach and acquisition in two cylindrical geometries (pyramidal and conical), find optimal number of incremental scans required for detailed morphological studies and for accurate left ventricular (LV) volume evaluation. 2) Image Segmentation: Develop a two step algorithm for LV extraction in 3DE. The first step includes automated identification of the LV cavity and determination of a global threshold suitable for initial segmentation of the LV and cardiac structures. In the second step, an advanced algorithm for cavity boundary detection is used to create a 3D computer representation of the LV chamber. The algorithm simulates autonomous growth of a natural cell which adapts its shape to the surroundings. The software controlled growth and elastic properties of the "cell membrane" should reproduce the spatial distribution of the LV endocardial surface. The resulting 3D object will be used for qualitative and quantitative evaluation of the LV. 3) Clinical Validation and Application: Accuracy of LV volumetry by 3DE will be validated through the comparison of this method to volumetry by computed tomography. Patients with normal and symmetrically or asymmetrically enlarged LV will be selected. The validated 3DE algorithm will be subsequently applied to studies in patients with ischemic, valvular and congenital heart diseases examined in the Clinical Echocardiographic Laboratory. The significance of the project is that comprehensible 3DE images of cardiac anatomy and accurate LV volumetry will improve the quality of the diagnosis, treatment, and follow-up of patients with cardiovascular diseases.