SUB-MICRON X-RAY TOMOGRAPHY OF CALCIFIED TISSUE

钙化组织的亚微米 X 射线断层扫描

• 批准号: 2677650
• 负责人: MICHAEL G. FLYNN
• 金额: $ 9.99万
• 依托单位: HENRY FORD HEALTH SYSTEM
• 依托单位国家: 美国
• 财政年份: 1998
• 资助国家: 美国
• 起止时间: 1998-09-01 至 2000-08-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/2677650
• 关键词: X ray; bioengineering /biomedical engineering; biomedical equipment development; bone imaging /visualization /scanning; calcification; charge coupled device camera; clinical biomedical equipment; computer data analysis; digital imaging; human tissue; image enhancement; image processing; method development; particle accelerators; radiation detector; scintillation cameras; tomography

DESCRIPTION (Adapted from the applicant's abstract): Calcium precipitates in human tissue as a part of the formation of bone, teeth, or in certain abnormal processes (i.e., such as benign or malignant calcifications of the breast, vascular plaque, stones formed in the kidney or gallbladder, etc.). In bone, tissue is formed with a complex hierarchical structure which produces oriented material properties. Conventional microscopy methods are not suitable for studying this three dimensional (3-D) structure since both light and energetic electrons have minimal penetration into mineralized tissue. X-rays in the energy range from 7 to 11 keV penetrate small calcified tissue specimens of 50 to 250 micrometer dimension with characteristics that may permit measurement of the 3-D distribution of mineral concentration with a resolution of 0.1 to 0.5 micrometer. 3D X-ray microtomography is a method wherein many radiographic views of a specimen are acquired from different direction and the data reconstructed with a computer to produce an array (512 x 512 x 256) of values proportional to the X-ray attenuation coefficient of the specimen at many locations. Methods using microfocus X-ray tubes have been frequently used to study bone specimens with a size ranging from 4 to 20 mm with a resolution of 25 to 125 microns. Microtomography using synchrotron X-ray sources is capable of better resolution but detector limitations have limited present methods to a resolution of 2 to 25 micrometers. The applicant proposes to investigate a method using X-rays from a synchrotron source (the Advanced Photon Source, APS, at Argonne National Laboratory) which might achieve a resolution of 0.1 to 0.5 micrometer. An innovative approach using a zone plate to focus an X-ray beam to a sub-micron spot is proposed. The approach combines methods developed for scanning X-ray microscopy using lower X-ray energies and methods for tomographic reconstruction developed for cone beam tomography using electron beam X-ray sources. The methods developed will be evaluated using wet bone specimens. The ability to determine the 3-D ultrastructure with the collagen matrix, the structure and orientation of mineral within bone lamella, and the porosity of bone tissue will be specifically examined. If successful, this method will permit investigations of 3-D bone structure at a resolution that has previously not been possible.

描述(摘自申请者的摘要)：钙沉淀物 在人类组织中，作为骨骼、牙齿或某些组织形成的一部分 异常过程(例如，良性或恶性的钙化 乳房、血管斑块、肾结石或胆结石等)。 在骨骼中，组织由复杂的等级结构组成，这种结构 生成定向的材料特性。传统的显微镜检查方法有 不适合研究这种三维(3-D)结构，因为 光和高能电子对矿化的穿透最少。 组织。能量范围从7到11keV的X射线穿透小 50至250微米大小的钙化组织标本 可允许测量三维分布的特性 矿物浓度，分辨率为0.1至0.5微米。 3D X射线显微断层摄影术是一种方法，在这种方法中，许多 从不同方向采集标本，重建数据 用计算机产生成比例的值阵列(512x512x256) 对样品在多个位置的X射线衰减系数的影响。 使用微焦点X射线管的方法已被频繁地用于骨研究 尺寸从4毫米到20毫米的样品，分辨率为25到125 微米。使用同步加速器X射线源的微层析成像能够 更好的分辨率，但探测器的限制使目前的方法仅限于 分辨率为2到25微米。 申请人建议研究一种使用来自 同步加速器源(Argonne National的高级光子源，APS 实验室)，可能达到0.1到0.5微米的分辨率。一个 使用波带板将X射线束聚焦到 提出了亚微米光斑的概念。该方法结合了为 使用较低X射线能量的扫描X射线显微镜和方法 锥束电子层析成像的层析重建技术 束流X射线源。 开发的方法将使用湿骨标本进行评估。这个 用胶原蛋白基质确定三维超微结构的能力 骨板内矿物的结构和取向，以及孔隙率 将对骨组织进行专门检查。如果成功，则此方法 将允许在具有以下分辨率的情况下研究3D骨骼结构 以前是不可能的。