- X-ray Microscopy (XRM) is an advanced imaging technique that uses high-energy X-ray radiation to visualize the internal structures of objects with high resolution, often surpassing that of traditional optical microscopy.
- Unlike conventional X-ray imaging, which produces 2D projections, X-ray microscopy is designed to generate detailed three-dimensional (3D) images, allowing for in-depth examination of complex internal features without physically sectioning the sample. This capability makes XRM particularly valuable in fields such as materials science, biology, and medicine, where understanding internal microstructures is crucial.
- The core principle of X-ray microscopy involves focusing a coherent or semi-coherent X-ray beam onto a small region of the sample. The X-rays penetrate the specimen and are either transmitted or scattered depending on the internal composition and density variations within the sample.
- Advanced focusing optics, such as Fresnel zone plates or capillary optics, are used to concentrate the X-ray beam to a fine point, enabling high spatial resolution imaging at the micrometer or even nanometer scale. The collected transmitted X-rays form an image either directly or after passing through a series of projections taken from multiple angles.
- X-ray microscopy can operate in various modes, including absorption contrast, phase contrast, and fluorescence imaging, each offering different types of information about the sample’s internal structures.
- Absorption contrast highlights differences in density or atomic number, useful for distinguishing between different materials or tissue types.
- Phase contrast enhances features with small differences in optical path length, making it advantageous for imaging soft biological tissues with low inherent contrast.
- Fluorescence mode detects emitted X-ray fluorescence from specific elements within the sample, facilitating elemental or chemical analysis.
- Data collection in X-ray microscopy often involves rotating the sample and capturing a series of 2D images at different angles—a process known as computed tomography (CT). These projections are then reconstructed computationally to generate highly detailed 3D representations of the internal architecture. This approach provides invaluable insights into the morphology and composition of specimens, such as biological tissues, mineral samples, or engineered materials.
- The non-destructive nature of XRM, combined with its high-resolution capabilities, enables researchers to study samples in their native state, making it a vital tool for scientific exploration and analysis across multiple disciplines.
