Low-dose Myocardial Perfusion Imaging by CT

描述（由申请人提供）本提案的目的是开发临床可行的策略，用于通过动态计算机断层扫描（CT）成像定量估计心肌血流量（MBF），其辐射剂量与普通核心肌灌注研究中接收的辐射剂量相当。尽管定量MBF（以ml/g/min计）的临床价值已得到证实，但尚无广泛的临床方法以绝对单位轻松测量MBF。动态CT提供了量化血流的潜力，但这些研究所给予的辐射剂量阻止了广泛的接受。该提案的具体目标是开发1）最佳心肌血流量估计方法，2）用于MBF估计的低剂量动态CT采集策略，3）无偏数据恢复算法和4）基于权衡空间分辨率以降低噪声和利用先验知识约束噪声的图像重建方法。这些目标将通过模拟动态对比增强CT成像来实现，并通过患者检查进行评价。我们假设，通过选择采集策略和明智地应用降噪策略，可以用低剂量动态CT确定准确的内膜下和内膜下MBF估计值。这项工作提出了新的低剂量采集和数据/图像增强策略，使准确的定量估计血流量的绝对单位毫升/克/分钟。这些方法将允许大幅减少辐射剂量，这是必不可少的患者安全，临床应用的动态CT MBF测量，并为其他证明应用动态CT。这项工作将心脏动态CT定位为一种安全，简单，广泛使用的定量MBF估计工具，提供有价值的临床信息，定量血流限制性疾病，尽量减少不必要的导管插入术，告知治疗选择，并开发新的治疗方法。

DESCRIPTION (provided by applicant) The objective of this proposal is to develop clinically viable strategies for the quantitative estimation of myocardial blood flow (MBF) from dynamic computed tomography (CT) imaging with low radiation doses comparable to those received in common nuclear myocardial perfusion studies. Despite the proven clinical value of quantifying MBF (in ml/g/min), there are no widespread clinical methods to easily measure MBF in absolute units. Dynamic CT offers the potential to quantify flow, but the radiation dose imparted from these studies prohibits widespread acceptance. The specific aims of the proposal are to develop 1) optimal myocardial blood flow estimation methods, 2) low-dose dynamic CT acquisition strategies for MBF estimation, 3) unbiased data restoration algorithms and 4) image reconstruction methods based on trading off spatial resolution for noise reduction and constraining noise with a priori knowledge. These aims will be developed with simulations of dynamic contrast enhanced CT imaging and evaluated with patient exams. We hypothesize that accurate subendo- and subepi-cardial MBF estimates can be determined with low- dose dynamic CT through selection of acquisition strategies and judicious application of noise reduction strategies. This work proposes novel low-dose acquisition and data/image enhancement strategies to enable accurate quantitative estimates of blood flow in absolute units of ml/g/min. These methods will allow for substantial reductions in radiation dose, which is essential for patient safety, clinical application of dynamic CT for MBF measurement, and for other proven applications of dynamic CT. This work will position cardiac dynamic CT as a safe, easy, and widely available tool for quantitative MBF estimation, providing valuable clinical information for quantification of flow limiting disease, minimizing unnecessary catheterization procedures, informing therapy choices, and developing new therapies.