Phase Contrast Computed Tomography Scanner

相衬计算机断层扫描仪

• 批准号: 7023153
• 负责人: EDWIN F DONNELLY
• 金额: $ 14.48万
• 依托单位: VANDERBILT UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2005
• 资助国家: 美国
• 起止时间: 2005-12-27 至 2007-11-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7023153
• 关键词: bioimaging /biomedical imaging; biomedical equipment development; computed axial tomography; image enhancement; mathematical model; neoplasm /cancer imaging; radiation dosage

DESCRIPTION (provided by applicant): While computed tomography (CT) imaging is by far the most predominant anatomical imaging device used to evaluate non-neurological malignancies in humans, its role in imaging small animal malignancies (especially rodent models of human tumors) has been much more limited due to the unacceptably high radiation dose levels necessary to image at the needed spatial resolution. These doses can interfere with tumor growth and metabolism and thus may compromise the actual scientific studies the scans were intended to evaluate. The development of phase-contrast imaging, however, offers one potential mechanism for improving soft tissue tumor detectability in small animals with potentially lower radiation doses. Phase-contrast imaging utilizes the diffraction of x-rays as they pass through tissue interfaces to obtain additional information not available to traditional absorption radiography. In addition, these images have a characteristic edge-enhancement effect that tends to increase lesion conspicuity. Because the technique depends upon the diffraction, rather than absorption, of x-rays, these images can be obtained at radiation doses potentially much lower than conventional absorption radiographs. Our laboratory has been investigating phase-contrast radiography (PC-R) for several years, and recently we have partnered with the x-ray source development group of the Free Electron Laser (PEL) Laboratory (located on the Vanderbilt University Campus) to investigate the feasibility of incorporating a newly- developed high-intensity x-ray production device into our existing PC-R system. The x-ray source is completely independent of the Free Electron Laser itself and has been designed specifically to function as a "table-top" source that could be generally available to medical facilities. The x-ray beam produced by this source is largely monochromatic and has an extremely high spatial coherence (the central requirement of phase-contrast imaging). In addition, it has been designed to provide a high x-ray flux. We now propose to extend that work into the development of a phase-contrast computed tomography scanner (PC-CT). In this study, we will optimize the imaging parameters and CT reconstruction algorithms for PC-CT and we will determine whether a small-animal PC-CT scanner is feasible by comparing PC-CT to a commercial, state-of- the-art small-animal microCT scanner using quantifiable data from images of a custom phantom and radiation dose measurements.

描述(申请人提供)：虽然计算机断层扫描(CT)成像是迄今为止用于评估人类非神经系统恶性肿瘤的最主要的解剖成像设备，但由于以所需的空间分辨率成像所需的不可接受的高辐射剂量水平，其在成像小动物恶性肿瘤(尤其是啮齿动物肿瘤模型)中的作用已受到很大限制。这些剂量可能会干扰肿瘤的生长和新陈代谢，因此可能会损害扫描旨在评估的实际科学研究。然而，相位对比成像的发展为提高小动物软组织肿瘤的检测能力提供了一种潜在的机制，而辐射剂量可能更低。 相衬成像利用X射线通过组织界面时的绕射来获得传统吸收射线成像所不具备的额外信息。此外，这些图像具有独特的边缘增强效果，往往会增加病变的显着性。由于这项技术依赖于X射线的绕射，而不是吸收，因此这些图像可以在可能比传统吸收射线照片低得多的辐射剂量下获得。 我们的实验室多年来一直在研究相衬射线照相技术(PC-R)，最近我们与自由电子激光(PEL)实验室(位于范德比尔特大学校园)的X射线源开发小组合作，研究在我们现有的PC-R系统中引入新开发的高强度X射线产生设备的可行性。X射线源完全独立于自由电子激光器本身，并且被专门设计成一种可普遍用于医疗机构的“桌面”源。这种光源产生的X射线束主要是单色的，具有极高的空间相干性(相衬成像的中心要求)。此外，它还被设计成提供高X射线通量。我们现在建议将这项工作扩展到相衬计算机断层扫描仪(PC-CT)的开发中。在这项研究中，我们将优化PC-CT的成像参数和CT重建算法，并通过使用来自定制体模的图像和辐射剂量测量的可量化数据，将PC-CT与商用的最先进的小动物微型CT扫描仪进行比较，以确定小型动物PC-CT扫描仪是否可行。