Development and Application of the non-invasive high-resolutional structural analysis system for bone tissue

为了研究动物骨密度和三维结构研究的实验阶段所发生的变化，开展了高分辨率微焦点X射线计算机断层扫描(Micro CT)的研制。[图像条件与曝光辐射剂量和图像质量的关系和考虑。]通过使用锥形束式高灵敏度探测器和缩短曝光时间，我们实现了三维图像重建的加速。与目前使用的其他方法相比，照射时的辐射剂量降低了1/16-1/50，但110微伏的理想靶点产生的辐射剂量是其他方法的12-35倍。为了进一步减少暴露的辐射剂量，对高灵敏度探测器进行了重新检查，并使用2048x2048像素12位数字平板探测器进行了试验。[开发了一种可以稳定动物以与x-ra…一起使用的硬质工作台我们成功地完成了用于狗、猴、兔和其他较大动物的微型CT设备的初步设计。[建立了骨体密度测量和评估系统。]对于具有相同体积密度体模的皮质骨和具有相同体密度体模的松质骨的几种组合，实现了皮质骨和松质骨的CT值定量效果相同的方法。通过这种方法，可以精确地获得松质骨的绝对密度。[新开发的高分辨率微型CT的应用。]可以清楚地观察到卵巢切除后猴子下颌骨的变化，以及给予维生素D剂量的小鼠的变化和Gli基因敲除小鼠的骨骼异常。这些发现发表在日本骨与矿物研究学会年会和美国骨与矿物研究学会年会上。较少

The development of high-resolutional microfocus x-ray computed tomography(micro CT)was carried out in order to investigate the kind of changes occurring during the experimental stages of the study of the bone density of animal and three dimensional structure.[Relationships and considerations of image conditions regarding exposed radiation dose and image quality.]Through utilization of a cone beam type high-sensitivity detector and a shortened exposure time, we achieved a speeding-up of the reconstruction of a 3D image. At the time of exposed radiation dose was reduced by 1/16-1/50 compared with other methods used to date, however the desired target of 110 micro SV resulted in 12-35 times the radiation dosage. In order to reduce the exposed radiation dose even further, the high-sensitivity detector was re-examined and trials were carried o utilizing a 2048 x 2048 pixel 12 bit digital flat panel detector.[Development of a rigid table upon which animals can be stabilized for use with x-ra … More y computed tomography equipment.]We successfully completed a preliminary design of micro CT equipment for use with dogs, monkeys, rabbits and other larger animals.[Establishment of a bone volume density measurement and evaluation system.]Regarding several combinations of cortical bone with the same volume density phantom and trabecular bone with the same volume density phantom, it became possible to achieve a method by which the CT value quantitative effect received for both cortical bone and trabecular bone was the same. In this way the absolute density of the trabecular bone can be precisely obtained.[Applications of the newly developed high-resolutional micro CT.]Changes in monkey mandible achieved through ovaliextomy and the changes in a mouse which had been administered with doses of vitamin D and skeletal abnormality of the Gli-gene knock out mouse could be clearly observed. These findings were reported at both the Annual Meeting of the Japanese Society for Bone and Minearl Research and the Annual Meeting of the American Society for Bone and Mineral Research. Less