IMAGING AND VOLUMETRY IN 3-DIMENSIONAL ECHOCARDIOGRAPHY

该项目的主要重点是开发和验证一个高度 用于准确定性（形态学）的自动化临床可行系统 和定量（容积法）评估心脏的三维 超声心动图（3DE）。 本研究的具体假设是：人体心脏的3DE图像 可以提供更准确的定性和定量信息， 二维超声心动图。 目的是测试 假设在以下领域：1）图像采集;使用 两种圆柱形几何结构中的经食管入路和采集 （金字塔形和圆锥形），找到所需的最佳增量扫描次数 用于详细的形态学研究和准确的左心室（LV） 体积评价 2)图像分割：开发两步算法 用于3DE中的LV提取。 第一步包括自动识别 的LV腔和确定适用于 LV和心脏结构的初始分割。 在第二步中， 一个先进的算法腔边界检测是用来创建一个三维 LV腔室的计算机表示。 该算法模拟了 自然细胞的自主生长，使其形状适应 四周 该软件控制的增长和弹性性能的 “细胞膜”应该再现LV的空间分布 内表面 生成的3D对象将用于定性 和LV的定量评价。3)临床确认和 应用：通过3DE进行LV容量测定的准确性将通过 该方法与计算机断层扫描容量法的比较。 患者 左心室正常、对称或不对称增大， 选定. 经确认的3DE算法随后将应用于 缺血性、瓣膜性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， 心脏解剖结构和准确的LV容量测定将提高 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.