Improved C-Arm CT for Interventional Procedures

描述（由申请人提供）： 在X射线荧光镜引导下使用血管内入路的微创手术使以前没有选择的患者能够得到治疗。即使在可能是手术候选人的患者中，微创手术也可能是首选，因为其风险更低，恢复更快，成本更低。这些应用包括使用支架治疗腹主动脉瘤以及使用溶栓和栓塞剂进行颅内介入治疗。使用X线透视的引导非常适合这些手术的许多方面，但是它无法描述许多潜在的并发症，例如内漏（发生在20-30%的主动脉支架中）或颅内出血，也无法充分探索血液动力学参数，例如血容量。通常，患者需要进行后续CT扫描。虽然使用C形臂的断层摄影成像被用于对高对比度对象进行成像，但是基本问题已经阻止了这些系统为许多重要任务提供足够低的对比度灵敏度。 我们建议大大提高C形臂CT的低对比度性能，从而在介入手术期间提供X射线荧光透视和更高质量的基于C形臂的CT图像。改进的C形臂CT将使介入实验室的低对比度分辨率接近传统CT，并改善这些手术的图像引导。我们将解决散射、欠采样和射束硬化等问题，并开发硬件和软件来改善低对比度检测，具体目标是检测40 HU对比度（+/-10 HU噪声）的10 mm物体。我们将优化采集和测量方案，以指导腹主动脉支架植入术和颅内介入术，并在体外和猪模型中进行测试。我们希望证明能够描述支架与血管壁和血栓之间的关系，可视化内漏，估计血容量，并检测新鲜颅内出血。这个项目的重要性被这样一个事实放大了，即这里开发的技术最终可能影响许多其他微创手术。

DESCRIPTION (provided by applicant): Minimally invasive procedures using endovascular access under x-ray fluoroscopic guidance have enabled treatment of patients that previously had no options. Even in patients who may be surgical candidates, minimally invasive procedures may be preferred because of their lower risk, faster recovery, and lower cost. Among these applications are the treatment of abdominal aortic aneurysms using stents and intracranial interventions with thrombolytic and embolic agents. Guidance using x-ray fluoroscopy is well-suited for many aspects of these procedures, however it is unable to depict a number of potential complications, such as endoleaks (which occur in 20-30% of aortic stents) or intracranial bleeding, nor to fully explore hemodynamic parameters such as blood volume. Often, patients require follow-up CT scans. While tomographic imaging using C-arms is being used for imaging high-contrast objects, basic problems have prevented these systems from providing sufficient low contrast sensitivity for a number of important tasks. We propose to greatly improve the low-contrast performance of C-arm CT, and thereby provide both x-ray fluoroscopy and much higher quality C-arm-based CT images during interventional procedures. The improved C-arm CT will bring low contrast resolution approaching that of conventional CT into the interventional lab and improve image guidance for these procedures. We will address problems such as scatter, under-sampling and beam hardening, and develop hardware and software to improve low-contrast detection with the specific goal of detecting a 10 mm object of 40 HU contrast (+/-10 HU noise). We will optimize acquisition and measurement protocols for the guidance of abdominal aortic stenting and intracranial interventions, and test these in vitro and in a porcine model. We expect to demonstrate the ability to depict the relationship among a stent and the vessel wall and thrombus, to visualize endoleaks, to estimate blood volume, and to detect fresh intracranial bleeds. The significance of this project is amplified by the fact that the technology developed here could eventually impact many other minimally invasive procedures.