C-Arm CT for Guidence of Cardiac Interventions

描述（由申请人提供）：在X线透视引导下使用血管内入路的微创心脏手术能够治疗以前需要心内直视手术的患者。这种微创手术是优选的，因为其风险较低、恢复较快和成本较低。发展最快的手术之一是用于治疗房颤的消融术-最终有20%的人口患有房颤，并且是中风、患者发病率和死亡率的重要因素。虽然有希望，但首次干预的手术成功率仍然只有~50%，即使进行后续干预，最终结局成功率也徘徊在~ 70%。据推测，导致成功率有限的主要因素是缺乏关于所创建病变的确切数量和位置的精确知识。我们建议利用和扩展我们最近开发的ECG门控心脏C形臂CT，以在介入手术期间提供三维成像。通过利用介入套件中的X射线系统生成3D图像，将避免与先前CT或MRI检查进行的容易出错且耗时的时空配准。反映患者当前状态的详细三维图像将与电解剖标测图相结合，以最佳方式协助介入医生。我们的目标是通过缩短透视引导所需的时间和采用多维降噪算法来减少患者和工作人员的辐射剂量。我们将通过解决欠采样、采集时序和时间清晰度问题，以及通过开发硬件和软件来提高低对比度性能、配准精度和可视化，从而提高图像质量。我们的目标之一是证明描绘左心房和肺静脉的能力，以提供优于2 mm的引导精度，并将配准所需的时间减少50%（约20分钟）。随着这些发展，我们的最终目标是实现更快、更准确的导管介入，成功率与外科手术相当（80-90%）。该项目的重要性进一步放大，因为开发的技术最终可能影响许多其他当前的微创手术，以及未来的手术，例如用于治疗心肌梗死的干细胞内注射。项目叙述该项目旨在在介入手术期间提供介入手术室中跳动心脏的高质量3D CT图像。我们认为，提供反映患者在介入时真实状态的图像，与器械跟踪硬件结合使用，将显著提高准确性，并缩短复杂手术（如房颤射频消融术）的手术时间。我们还在开发新的图像处理和重建方法，可以实现心脏壁射频病变的3D可视化，从而可以在术中监测病变位置。在介入手术期间访问这样的图像还可以通过允许治疗（细胞、药物等）的准确引导来实现针对心肌梗死的新的定向治疗。直接注射到受影响的组织

DESCRIPTION (provided by applicant): Minimally invasive cardiac procedures using endovascular access under x-ray fluoroscopic guidance have enabled treatment of patients that previously would have required open-heart surgery. Such minimally invasive procedures are preferred because of their lower risk, faster recovery and lower cost. One of the fastest growing procedures is ablation for treatment of atrial fibrillation - a problem eventually suffered by 20% of the population and a significant contributor to stroke, patient morbidity and mortality. While promising, procedure success rates are still only ~50% for the first intervention, and even with subsequent interventions, final outcome success hovers at ~70%. It is hypothesized that a major factor contributing to the limited success rate is the lack of precise knowledge about the exact number and location of the created lesions. We propose to leverage and expand upon our recent development of ECG gated cardiac C-arm CT to provide three-dimensional imaging during the interventional procedure. By generating 3D images utilizing the x-ray system in the interventional suite, the error prone and time-consuming spatio-temporal registration with prior CT or MRI exams will be avoided. Detailed three- dimensional images reflecting the current state of the patient will be combined with electroanatomical maps to optimally assist the interventionalist. We aim to also reduce the radiation dose to both patients and staff by shortening the time needed for fluoroscopic guidance and by incorporating multi-dimensional noise reduction algorithms. We will develop image quality improvements by addressing under-sampling, acquisition timing and temporal definition, and by developing hardware and software to improve low-contrast performance, registration accuracy and visualization. One of our goals is to demonstrate the ability to depict the left atrium and pulmonary veins to provide guidance accuracy of better then 2 mm, and to reduce the time required for registration by 50% (~20 minutes). With these developments our ultimate goal is to accomplish faster and more accurate catheter based interventions with an equivalent success rate as surgical procedures (80-90%). The significance of this project is further amplified by the fact that the technology developed could eventually impact many other current minimally invasive procedures, and also future procedures as they become available, such as endocardial injection of stem cells for treatment of myocardial infarction. Project Narrative The project aims to provide high-quality 3D CT images of the beating heart in the interventional suite during an interventional procedure. We believe that providing images that reflect the true status of the patient at the time of intervention, when combined with device-tracking hardware, will provide significant improvements in accuracy and reduction in procedure times for complicated procedures such as radiofrequency ablation of atrial fibrillation. We are also developing new image processing and reconstruction approaches that may permit 3D visualization of radiofrequency lesions in the heart wall that would allow intra-procedural monitoring of lesion placement. Access to such images, during an interventional procedure, could also enable new, directed treatments for myocardial infarction by allowing accurate guidance of therapy (cell, drug etc.) directly to the affected tissue.