Quantitative X-ray Phase Contrast Imaging

X射线在研究体积大和不透明的样品方面是独一无二的，正如其在医学、安全和无损检测方面的广泛应用所证明的那样。X射线相衬成像（XPCI）方法克服了传统射线照相术的局限性，特别是对于那些表现出低吸收的样品。生物软物质主要由低Z元素组成，它们不以高概率吸收X射线，但检测X射线波前中相位畸变的能力使X射线不可见的细节可视化。先进X射线成像集团（阿克西姆）率先开发了紧凑型XPCI系统，并与尼康合作建立了第一个原型，用于乳腺组织的术中成像。图像质量大大上级当前的临床标准，但是图像的解释仍然主要是定性的，并且高度依赖于受试者。校准和不确定度评估是仪器可追溯性的基本要素，国家物理实验室NPL正在领导国家和国际层面尺寸计量X射线CT的发展。为应用于医疗领域的XPCI micro-CT创建计量框架将是将三维图像转换为绝对测量的努力中的一个步骤，其中仪器的偏差，精度和准确度是已知的并具有特征。该项目旨在开发模型和技术，以融合最先进的X射线成像技术，为软组织和更一般的低Z材料提供独特的灵敏度，并提供完全定量和可追溯的测量方法。绝对的定量测量将使不同实验、不同实验室和不同时间点的样本比较成为可能，也是有意义的，改变了研究人员、临床医生和开发人员看待样本的方式。这些新的方法将提供一个途径，改变X射线微型CT应用在广泛的应用，包括三维成像的组织在临床应用，设计和制造和临床前的小动物调查。为工程和技术、人工智能以及改变健康和医疗保健领域的前沿战略重点做出贡献。国家物理实验室（NPL）和尼康将与该项目合作。

X-rays are unique for investigating bulky and opaque samples, as their broad use in medicine, security and non-destructive inspection demonstrates. X-ray phase contrast imaging (XPCI) methods overcome the limitations of conventional radiography, especially for those samples exhibiting low absorption. Biological soft matter is mostly composed of low-Z elements, which do not absorb X-rays with high probability, but the capability of detecting phase distortions in the X-ray wavefront enables visualising details that would be otherwise X-ray-invisible. The Advanced X-ray Imaging Group (AXIm) has pioneered the development of compact XPCI systems, and a partnership with Nikon has built a first prototype, field deployed for intraoperative imaging of breast tissue. The image quality was vastly superior to the current clinical standards, however the interpretation of images remained largely qualitative and highly subject-dependent. Calibration and uncertainty evaluation are fundamental elements of instrument traceability and the National Physical Laboratory NPL is leading the development of X-ray CT for dimensional metrology at national and international levels. The creation of a metrology framework for XPCI micro-CT applied in the medical field would be a step change in the efforts to transform three-dimensional images into absolute measurements, where the instrument's bias, precision, and accuracy are known and characterised. The project aims at developing models and techniques to merge the most advanced X-ray imaging techniques, providing unique sensitivity for soft-tissues and more in general low-Z materials, with a fully quantitative and traceable measurement methodology. Absolutely quantitative measurements will make possible, and meaningful, the comparison of samples across different experiments, different labs, and different points in time, shifting the way researchers, clinicians and developers look at specimens. These new approaches would provide a pathway for transforming X-ray micro-CT applications across a wide spectrum of applications, encompassing three-dimensional imaging of tissue in clinical applications, design and manufacturing and pre-clinical small-animal investigations.This program aligns well with the EPSRC research areas of light matter interaction, medical imaging and sensors and instrumentation; contributing to the strategic priorities of frontiers in engineering and technology, ai and transforming health and healthcare.Both the National Physical Laboratory (NPL) and Nikon will be collaborating with this project.