Cardiovascular CT Clinical Research

总结 具体目的1：研究负荷CT灌注诊断的准确性 CT扫描仪可以获得高质量的冠状动脉图像。CT冠状动脉造影对绝大多数患者具有较高的诊断准确性，但可能没有足够的分辨率或图像质量来评估冠状动脉支架和严重钙化血管的通畅性。利用CT对负荷心肌灌注成像有助于解决这些特殊患者亚群的诊断不确定性。此外，虽然整体分辨率高，但是用于对3mm动脉中的冠状动脉狭窄的严重性进行分级的CT扫描的分辨率可能是边缘的。因此，CT负荷灌注可以提供所需的生理评估的另一个领域，以帮助确定解剖狭窄是否严重到足以引起缺血或需要干预。为了解决这些问题，我们研究了58例患者，作为多中心Core320研究的一部分，该研究将CT冠状动脉造影和负荷CT灌注与传统的定量侵入性冠状动脉造影和SPECT灌注进行了比较。我们是这项研究的主要北美招募网站，该研究最近关闭了招募。 此外，我们正在进行一项辅助研究，包括CT灌注与负荷MRI灌注的比较。这项辅助研究正在分析中。 具体目标2：开发低剂量心脏CT成像方案，保持高诊断准确性。 另一个紧迫的研究方向是开发低辐射剂量的心脏CT扫描。公众和学术医学界都认识到，诊断成像的辐射照射正在迅速增加，并可能与一些健康风险有关。因此，寻找减少心脏CT扫描中辐射暴露的方法是一个重要的优先事项。据我们所知，NHLBI心脏CT程序在使用320探测器CT扫描仪的任何部位中具有最低的平均辐射暴露。我们正在领导研究，以改进技术并创建更低剂量的CT成像协议。 具体目标3：开发结构性心脏病介入的CT计划方法。 NHLBI开发了将大型植入物引入主动脉进行经导管主动脉瓣置换术和相关手术的新技术。 CT可用于计划这些复杂的手术，这些手术可以挽救生命。 NHLBI作为CT核心实验室进行多中心试验，以评估该技术在美国的安全性和有效性。 具体目标4：为其他NIH研究人员提供安全准确的心血管表型。 心血管CT实验室与来自心脏病学分支以及NHLBI和其他机构的其他研究人员一起，提供执行和解释心血管CT和MR检查的专业知识。 这些数据为多种系统性和罕见遗传性疾病的心脏和血管病理生理学提供了有价值的信息。

Summary Specific Aim 1: Study the diagnostic accuracy of stress CT perfusion CT scanners can acquire high quality images of the coronary arteries. CT coronary angiography has high diagnostic accuracy in the great majority of patients but may not have sufficient resolution or image quality to assess the patency of coronary stents and heavily calcified vessels. Using CT to image stress myocardial perfusion could help solve the diagnostic uncertainty in those special subsets of patients. In addition, while high resolution overall, the resolution of a CT scan for grading the severity of a coronary stenosis in a 3 mm artery can be marginal. Therefore, another area where CT stress perfusion could provide the physiologic assessments needed to help determine whether an anatomic stenosis is severe enough to have caused ischemia or warrant intervention. To address these issues, we have studied 58 patients as part of the multicenter Core320 study which compares CT coronary angiography and stress CT perfusion with conventional quantitative invasive coronary angiography and SPECT perfusion. We were the leading North American recruitment site for this study which recently closed enrollment. Additionally, we are leading an ancillary study that includes comparison of CT perfusion with stress MRI perfusion. That ancillary study is under analysis. Specific Aim 2: Develop low dose cardiac CT imaging protocols that retain high diagnostic accuracy. Another pressing research direction has been developing low radiation dose CT scans of the heart. The public and academic medical communities have both realized that radiation exposure from diagnostic imaging is increasing at a rapid pace and may be associated with some health risks. Thus, finding methods for reducing radiation exposure in CT scans of the heart is a significant priority. To the best of our knowledge, the NHLBI cardiac CT program has the lowest average radiation exposure of any site using the 320 detector CT scanner. We are leading investigations to improve the technology and create even lower dose CT imaging protocols. Specific Aim 3: Develop CT planning methods for structural heart disease interventions. New techniques to introduce large implants into the aorta for transcatheter aortic valve replacement and related procedures have been developed at NHLBI. CT can be used to plan these complex procedures which can be lifesaving. NHLBI serves as the CT Core Lab for a multicenter trials to evaluate the safety and efficacy of this technique throughout the USA. Specific Aim 4: Provide safe and accurate cardiovascular phenotyping for other NIH investigators. In conjunction with other investigators from not only the Cardiology Branch, but also NHLBI and other institutes, the Laboratory of Cardiovascular CT provides expertise in performing and interpreting cardiovascular CT and MR exams. This data provides valuable information on the cardiac and vascular pathophysiology of multiple systemic and rare genetic diseases.