Test and optimization of a multi-modal phase-based x-ray microscope for soft tissue imaging
Test and optimization of a multi-modal phase-based x-ray microscope for soft tissue imaging
复制标题
用于软组织成像的多模态相位 X 射线显微镜的测试和优化
DOI：
--
复制
发表时间：
2022
期刊：
影响因子：
--
通讯作者：
A. Olivo
中科院分区：
文献类型：
--
作者：
M. Esposito;L. Massimi;I. Buchanan;J. Ferrara;M. Endrizzi;A. Olivo
组织成像是生物医学研究和临床实践的关键组成部分。为了识别细胞水平的组织结构，需要能够以微米到亚微米的分辨率对mm大小的未染色组织样本进行成像。组织成像通常使用X射线或可见光进行。虽然后者受到相对厚的组织中的光散射的限制，但前者通常在基于吸收的系统中遭受差的对比度。存在相衬X射线显微镜，但它们通常缺乏所需的定量性，需要数十小时的3-D成像的数量级的采集时间，并且限于狭窄的视场。我们提出了一种新的多模态相位为基础的X射线显微镜，能够成像毫米厚的组织样本上毫米大小的视场使用强度调制掩模。它们充当光学元件，允许定量检索组织特性，如透射、折射和散射。此外，考虑到系统的空间分辨率仅取决于掩模孔径大小，通过选择孔径大小与特定样品的分辨率要求（微米和亚微米）相匹配的掩模，多分辨率方法是可能的。本文介绍了X射线显微镜的设计和优化，以及从三个对比通道的检索中得到的薄泡沫样品的示例图像。最后的论文将包括系统参数优化的细节（例如，传播距离、掩模孔径和周期），它们对检索算法和成像性能以及生物样品的第一图像的影响。
Tissue imaging is a pivotal component of both biomedical research and clinical practice. In order to identify tissue structures down to the cellular level, it requires the capability to image mm-size unstained tissue specimens with micron to sub-micron resolution. Tissue imaging is normally performed either using x-rays or visible light. While the latter is limited by light scattering in relatively thick tissues, the former often suffers from poor contrast in absorption-based systems. Phase-contrast x-ray microscopes exist but they often lack the required quantitativeness, entail acquisition times of the order of tens of hours for 3-D imaging and are limited to narrow fields of view. We propose a novel multi-modal phase-based x-ray microscope capable of imaging mm-thick tissue samples on a mm-size field of view using intensity-modulation masks. They act as optical elements allowing the quantitative retrieval of tissue properties such as transmission, refraction and scattering. Additionally, given that the system’s spatial resolution depends only on the mask aperture size, a multi-resolution approach is possible by selecting masks with aperture size matching the resolution requirements (micron and sub-micron) of specific samples. The design and optimization of the x-ray microscope is presented in this paper together with exemplar images of a thin foam sample resulting from the retrieval of the three contrast channels. The final paper will include details of the system parameter optimization (e.g., propagation distance, mask aperture and period), their effect on the retrieval algorithm and imaging performance as well as the first images of biological samples.