Cerbral Perfusion Imaging using Cone Beam Computed Tomography

描述(申请人提供)：中风是美国成年人致残的首要原因，也是导致死亡的第三大原因，每年约有70万新发或复发的中风。灌注计算机断层扫描(PCT)提供了脑血流量、容量和通过时间等参数的地图。这些参数可用于区分缺血性卒中和出血性卒中，确定低灌注区的位置和范围，以及区分不可逆转的受损组织和可挽救的组织。我们将研究在移动式平板探测器锥束CT(CBCT)系统上实施PCT的可行性。使用这样的平台将解决当前PCT技术的两个缺点：缺乏全脑覆盖以及急诊科和重症监护病房的可获得性有限。我们将关注两个问题：1)基于平板的CBCT扫描速度相对较低，这可能会阻碍对比度动力学的时间采样；以及2)投影噪声增加和平板探测器的动态范围有限。在这个项目中，我们将首先对用于成像碘增强血管的平板探测器的图像噪声和对比度特性进行实验研究。在研究的第二阶段，我们将开发和验证一种基于模型的迭代算法，用于重建使用相对较慢的旋转系统获取的动态投影数据。公共卫生相关性：在美国，中风是导致成人残疾的首要原因，也是导致死亡的第三大原因，每年约有70万新发或复发的中风。本文提出的能够进行灌注成像的移动式平板CT系统将允许在急诊科直接对全脑神经血管功能进行快速评估。这一工具可以提高中风的诊断水平，为治疗决策提供重要支持，从而极大地改善急性中风患者的预后。

DESCRIPTION (provided by applicant): Stroke is the leading cause of adult disability and third leading cause of death in the United States with approximately 700,000 new or recurrent strokes each year. Perfusion Computed Tomography (PCT) provides maps of parameters such as cerebral blood flow, volume and transit times. These parameters can be used to distinguish between ischemic and hemorrhagic stroke, to determine the location and extent of the hypoperfused area, and also to differentiate between the irreversibly damaged and salvageable tissue. We will investigate the feasibility of implementing PCT on a mobile, flat-panel detector, cone-beam CT (CBCT) system. Using such a platform will address two shortcomings of current PCT technology: lack of whole-brain coverage and limited accessibility in the emergency department and intensive care unit. We will focus on two issues: 1) relatively low scanning speed of flat-panel-based CBCT, which may hamper temporal sampling of contrast dynamics; and 2) increased projection noise and limited dynamic range of flat-panel detectors. In this project we will first experimentally investigate the characteristics of flat- panel detectors for imaging iodine enhanced vessels with respect to image noise and contrast. In the second stage of the research we will develop and validate a model- based, iterative algorithm for reconstruction of dynamic projection data acquired with relatively slowly rotating systems. PUBLIC HEALTH RELEVANCE: Stroke is the leading cause of adult disability and third leading cause of death in the United States with approximately 700,000 new or recurrent strokes each year. The mobile flat-panel-based CT system capable of perfusion imaging proposed here will allow for rapid assessment of neurovascular function of the whole brain directly in the emergency department. This tool may bring about improvements in stroke diagnosis and provide important support for treatment decisions, thus greatly improving outcome for acute strokes victims.