A High Resolution Imager for Tissue Specimen Radiography

用于组织样本射线照相的高分辨率成像仪

• 批准号: 7054923
• 负责人: Tumay O Tumer
• 金额: $ 9.98万
• 依托单位: NOVA R AND D, INC.
• 依托单位国家: 美国
• 财政年份: 2005
• 资助国家: 美国
• 起止时间: 2005-09-26 至 2007-08-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7054923
• 关键词: bioengineering /biomedical engineering; bioimaging /biomedical imaging; biomedical equipment development; charge coupled device camera; clinical biomedical equipment; microprocessor /microchip; neoplasm /cancer diagnosis; radiography; selenium; bioengineering /biomedical engineering; bioimaging /biomedical imaging; biomedical equipment development; charge coupled device camera; clinical biomedical equipment; microprocessor /microchip; neoplasm /cancer diagnosis; radiography; selenium

DESCRIPTION (provided by applicant): Accurate assessment of tissue specimens is a key requirement in the diagnosis of breast cancer. This requires images with high spatial and contrast resolution. A compact, high-resolution x-ray system for imaging of excised tissue specimens will be developed for use in the operating room. Currently, specimen radiography is performed in a cabinet x-ray unit where the image is acquired either on radiographic film or using a small area digital detector. Typically, the digital detector includes an x-ray absorbing phosphor, a fiber-optic coupler and an optical CCD camera. Such a detection system is limited in spatial and contrast resolution related to the use of phosphor technology and distortion and losses in the fiber-optic components. The new system will employ a novel direct conversion selenium CCD detector that will be used to form a slot scanning x-ray imaging system. It offers high x-ray detection and conversion efficiency, high limiting spatial resolution, low noise, linear response and high dynamic range. In the proposed system, the incoming x-rays are absorbed in a layer of selenium where their energy causes electric charge to be liberated. The selenium is directly evaporated onto a CCD readout chip. The charge is integrated in the readout chip and the signal is then digitized and sent to a computer for image processing and display. In Phase I the research plan consists of five goals. First, a small version of the CCD chip will be used in an experimental scanning system to simulate the full-scale specimen radiography system. To emulate a full-scale system, composite or "stitched" images will be made from multiple scans with the small- format chip. Imaging will be performed on tissue-equivalent plastic test objects. Second, the optimal geometry for image acquisition will be determined. For example, depending on the angle and trajectory of the detector, distortions associated with parallax will potentially limit resolution. Third, the optimal x-ray spectral energy will be determined. Tube output, required imaging time, contrast and dynamic range for high quality images will be considered in the optimization. Once this is achieved, the fourth goal will be to evaluate the importance of scattered radiation on image quality through modeling of signal and noise transfer and through experimental imaging using tissue-equivalent phantoms. If necessary, an anti-scatter technique will be used to reduce scatter. Finally, based on the results of these experiments we will prepare a preliminary design of a prototype digital specimen imager system to be built during Phase II. During Phase II, the full-size optimized CCD readout chip will be fabricated and tested and then integrated into a selenium detector with optimized thickness. The new detector's imaging capability and performance will be characterized. The system is expected to provide improved definition of fine tissue structures and aid in determining that the targeted focus of disease has been appropriately removed in biopsy or surgery. This should help ensure improved accuracy of resection of disease and provide a better link between pre- operative imaging and tissue histology.

描述（由申请人提供）：对组织标本的准确评估是诊断乳腺癌的关键要求。这需要具有高空间和对比度分辨率的图像。将开发用于切除组织样品的紧凑，高分辨率的X射线系统，用于在手术室中使用。目前，在橱柜X射线单元中进行样品X光照相，在该单元中，该单元在放射线照相膜上或使用小区域数字探测器上获取图像。通常，数字检测器包括X射线吸收磷光器，光纤耦合器和光学CCD摄像头。这种检测系统的空间和造影剂分辨率有限，与磷酸技术的使用以及失真以及光纤成分中的损失有关。新系统将采用一种新型的直接转换硒CCD检测器，该检测器将用于形成插槽扫描X射线成像系统。它提供高X射线检测和转换效率，高限制空间分辨率，低噪声，线性响应和高动态范围。 在拟议的系统中，传入的X射线被吸收在硒层中，它们的能量会导致电荷解放。硒直接蒸发到CCD读数芯片上。电荷集成在读取芯片中，然后将信号数字化并发送到计算机以进行图像处理和显示。在第一阶段，研究计划包括五个目标。首先，将在实验扫描系统中使用CCD芯片的小版本，以模拟全尺度标本X射线照相系统。为了模拟全尺度系统，将通过小型格式芯片进行多次扫描制成复合或“缝合”图像。成像将在组织等效的塑料测试对象上进行。其次，将确定用于图像采集的最佳几何形状。例如，根据检测器的角度和轨迹，与视差相关的失真可能会限制分辨率。第三，将确定最佳X射线光谱能。在优化中将考虑试管输出，所需的成像时间，对比度和动态范围。一旦实现这一目标，第四个目标将是通过建模信号和噪声传递以及使用组织等效幻象来评估散射辐射对图像质量的重要性。如有必要，将使用一种抗碎片技术来减少散射。最后，根据这些实验的结果，我们将准备在II期期间要构建的原型数字标本成像系统的初步设计。 在II期期间，将制造和测试全尺寸优化的CCD读数芯片，然后集成到具有优化厚度的硒检测器中。新的检测器的成像能力和性能将被表征。预计该系统将改善对细胞组织结构的定义，并有助于确定疾病的靶向重点已在活检或手术中得到适当去除。这将有助于确保改善疾病切除的准确性，并在手术成像和组织学之间提供更好的联系。