X-ray tomography as a tool for detailed anatomical analysis

Wood identification, anatomical examination and retrieval of quantitative information arc important aspects of many research disciplines. Conventional light microscopy with a camera and (semi)automatic image analysis software is an often used methodology for these purposes. Morc advanced techniques such as fluorescence, scanning electron, transmission electron, confocal laser scanning and atomic force microscopy arc also part of the toolset answering to the need for detailed imaging. Fast, non-destructive visualization in three dimensions with high resolution combined with a broad field of view is sought-after, especially in combination with flexible software. A highly advanced supplement to the existing techniques, namely X-ray sub-micron tomography, meets these requirements. It enables the researcher to visualize the material with a voxel size approaching <1 mu m for small samples (<1 mm). Furthermore, with tailor-made processing software quantitative data about the wood in two and three dimensions can be obtained. Examples of visualization and analysis of four wood species arc given in this paper, focusing on the opportunities of tomography at micron and sub-micron resolution. X-ray computed tomography offers many possibilities for material research in general and wood science in specific, as a qualitative as well as a quantitative technique.