Cardiovascular CT Research

具体目的1：研究负荷CT灌注成像的诊断准确性 如前所述，CT扫描仪可以获得高质量的冠状动脉图像。CT冠状动脉造影对大多数患者具有较高的诊断准确率，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一些严重钙化的血管的通畅性。使用CT对应激性心肌灌注成像可以帮助解决这些特殊亚群患者的诊断不确定性。此外，尽管总体分辨率很高，但CT扫描对3 mm动脉的冠状动脉狭窄程度进行分级的分辨率仍然很低。这是另一个CT应力灌注可以提供必要的生理评估的领域，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，我们对58名患者进行了研究，这是多中心Core320研究的一部分，该研究将CT冠状动脉造影/负荷CT灌注与定量有创冠状动脉造影/SPECT灌注进行比较。我们是这项研究的领先的美国招聘网站，最近结束了注册。结果尚待公布。 此外，我们正在领导一项辅助研究，其中包括CT灌注和负荷MRI灌注的比较。这项辅助研究也已完成登记，正在进行分析。 具体目标2：开发保持高诊断准确率的低剂量心脏CT成像方案。 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意识到，来自诊断成像的辐射暴露正在快速增加，可能与一些健康风险有关。因此，找到减少心脏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计划是使用320探测器CT扫描仪的所有地点中平均辐射暴露最低的。我们正在领导一项评估更低剂量的CT成像方案。初步结果已在全国会议上提出，并正在编写过程中。

Specific Aim 1: To study the diagnostic accuracy of stress CT perfusion As mentioned, 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 some 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 is still marginal. This is 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/ stress CT perfusion with quantitative invasive coronary angiography/SPECT perfusion. We were the leading US recruitment site for this study which recently closed enrollment. Results are pending. In addition, we are leading an ancillary study that includes comparison of CT perfusion with stress MRI perfusion. That ancillary study has also completed enrollment and is under analysis. Specific Aim 2: To 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 an assessing even lower dose CT imaging protocols. Preliminary results have been presented at National meetings and are in the process of being written.