Developmental Study of Very High Resolution Micro-focus X-ray Computed Tomography for Use in Medicine to Enable Acquisition of Images of Soft Tissues.

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Very high resolution micro-focus X-ray computed tomography, so called micro-CT, for industrial use has 10^2〜10^3 times greater spatial resolution than medical CT, however, the contrast resolution of both is low and nearly the same, making it difficult to resolve soft tissues that have nearly the same X-ray absorption values. If this problem were overcoming it would enable micro-CT to be used in a broad range of medical studies, from anatomy to clinical investigations, for example. An attempt was therefore made to design and manufacture both the hard- and soft-ware of a micro-CT system for medical study by using X-ray detection system of an image intensifier having a Be-window as its area sensor, which is never employed for micro-CT, and a direct MOS image sensor as a line sensor with a 21-bit AD conversion system, a bit-depth never achieved in the past with the conventional 16-bits. The system also unique features, such as reducing X-ray exposure and a multi-axis stage to obtain option … More al sections of the specimen.We have tried using this system to obtain continuous sections and produce 3D-reconstruction images of anatomical specimens and medical specimens. Using anatomical specimens, we successfully visualized and analyzed the cranium of asymmetric conjugated twins, especially the inner, middle, and external ear portions, whose structure it was been impossible to know for over forty years because its complexity.All previous reports on arteries employing micro-CT were studies of casts obtained by using contrast medium, and there had never been a study of the tunica vasculosa itself. By using the amputated crus from a patient of oxalosis as a clinical specimen, however, the calcification and pathology of the tunica media of the peroneal and tibial artery caused by deposition of calcium oxalate crystals was identified for the first time. The arteries of patients with arteriosclerosis and diabetes have also been imaged. The arteries of patients with arteriosclerosis caused by diabetes have also been imaged. As an example of the medical applications of micro-CT, we demonstrate that micro-CT is useful in obtaining information on the calcified part of soft tissues, although it is difficult to obtain conventional histological sections of calcified arteries because of the loss of calcified parts because of their hardness and fragility or because of dissolution during processing.We also describe the meaning and technical improvements in micro-CT as a tool for X-ray imaging anatomy and as practical medical equipment for the future. Less