Quantification of coronary calcium mass by dual energy fluoroscopy

描述（由申请人提供）：有效的预防策略需要早期检测亚临床动脉粥样硬化性心脏病。在这方面，冠状动脉钙的放射学检测和定量已经进行了广泛的研究。冠状动脉钙与病理结果和冠状动脉事件之间存在很强的相关性。最近的研究利用计算机断层扫描来评估冠状动脉钙。由于干扰背景组织结构和无法客观量化钙含量，荧光透视评价受到低灵敏度的限制。双能量成像不受这两个限制，并提供了一个较低的剂量和成本较低的解决方案，早期检测动脉粥样硬化。这项研究将开发一种运动不敏感的双能量减影技术，提供冠状动脉钙的密度测量。更具体地说，目的是：（1）研究假设，即冠状动脉中的绝对钙质量可以使用密度测定技术与体模和动物研究准确测量。将对组织抑制双能量图像进行密度测定分析，并将得出绝对（而不是相对）钙质量。(2)检验以下假设：在人类志愿者中采用双能量荧光透视法测量的钙质量与采用电子束计算机断层扫描法测量的钙评分之间的斯皮尔曼相关系数大于0.95。(3)确定两种技术在区分患有冠心病和没有患冠心病的人方面是否存在差异。这项研究将提供一种方法，无创定量冠状动脉钙使用双能量成像。最有可能的是，在未来几年，基于图像增强器电视系统的心脏成像将被平板探测器所取代。正如过去几年的快速发展所表明的那样，新的数字系统将允许开发更复杂的分析技术。基于密度测定的冠状动脉钙质量的定量是一种有前途的分析技术，新的数字系统可以提供。迄今为止，时间减影对心脏运动的敏感性阻碍了用于心脏成像的数字图像处理技术的发展。双能量成像，由于其运动不敏感性，可以作为定量心脏分析的基础。

DESCRIPTION (provided by applicant): Effective preventive strategies require early detection of sub-clinical atherosclerotic heart disease. Radiographic detection and quantification of coronary artery calcium has undergone extensive research in this regard. There is a strong association between coronary calcium and both pathologic findings and coronary events. Most recent research has utilized computed tomography for evaluating coronary calcium. Fluoroscopic evaluation is limited by low sensitivity, due to interfering background tissue structures and inability to objectively quantify calcium content. Dual energy imaging does not suffer from these two limitations and offers a lower dose and lower cost solution to early detection of atherosclerosis. The proposed research will develop a motion insensitive dual energy subtraction technique that will provide densitometry measurements of coronary calcium. More specifically, the aims are: (1) Investigation of the hypothesis that the absolute calcium mass in coronary arteries can be accurately measured using a densitometry technique with phantom and animal studies. The densitometry analysis will be performed on tissue suppressed dual energy images and will yield absolute (as opposed to relative) calcium mass. (2) To test the hypothesis that calcium mass measured in human volunteers with dual-energy fluoroscopy and calcium score measured with electron beam computed tomography have a Spearman correlation coefficient higher than 0.95. (3) To establish the presence or absence of a difference between the two technologies in discriminating persons with prevalent coronary heart disease from those without prevalent coronary heart disease. This research will provide a method to non-invasively quantify coronary artery calcium using dual energy imaging. Most likely, cardiac imaging with image intensifier television based systems will be replaced with flat-panel detectors in the coming years. As the rapid development in the last few years has shown, the new digital systems will allow development of more sophisticated analysis techniques. Densitometry based quantification of coronary artery calcium mass is one promising analytical technique that new digital systems may provide. To date, the sensitivity of temporal subtraction to cardiac motion has hampered the development of digital image processing techniques for cardiac imaging. Dual-energy imaging, because of its motion insensitivity, can serve as a foundation for quantitative cardiac analysis to proceed.