Development of 3D micron-CT to observe the interior of cells with high space resolving power and high-speed photograph

我们开发了“微米ct”，使用微派克进行体内成像。该系统由高分辨率（像素尺寸为8x8μm^2，像素数为1000x1000）的x射线CCD相机和由微光束照射纯金属靶产生的光斑尺寸为1.5x1.5μm^2的x射线点源组成。样品被放置在一个小直径的管子中，由步进电机旋转。利用锥束CT重建算法对获得的投影数据进行三维图像重建。我们利用这种微ct对小蚂蚁的内部结构进行了研究。考虑到探测，采用Ti作为x射线靶。CCD相机的效率。将福尔马林固定后的蚂蚁插入微米管。获得了空间分辨率为6 μm的蚂蚁头部三维图像，内部结构清晰可见。此外，我们开发了一种测量蚂蚁体内的方法。先用氯仿麻醉蚂蚁，然后将其插入微管。试管的内部保持在大气压力下，可以在体内进行测量。固定的蚂蚁和活的蚂蚁在图像上有很大的不同。在固定蚂蚁的情况下，由于福尔马林的固定，大脑萎缩，有些东西被冲走了。由于CCD对可见光敏感，我们还利用Al_2O_3（Cr）红宝石闪烁体发出的可见红光检测了光微米ct的能力，并将其应用于小红厚的研究。由于光的散射，得到了模糊的图像。三维微米ct可以提供高空间分辨率的活体样本的横切面图像，将对生物学研究有用。

We developed "micron-CT", using micro-PIKE for in-vivo imaging. This system comprises an X-ray CCD camera with high resolution (pixel size : 8x8μm^2, number of pixels : 1000x1000) and an X-ray point source with a spot size of 1.5x1.5μm^2 which is generated by irradiation of a microbeam on a pure metal target. The sample is placed in a tube of a small diameter, and rotated by a stepping motor. The 3D images were reconstructed from the obtained projection data by using a cone-beam CT reconstruction algorithm. We applied this micron-CT to investigate the internal structure of small ant. Ti was used as an X-ray target considering detection. efficiency of the CCD camera. An ant after formalin-fixation was inserted into a micron tube. The 3D images of ant's head were obtained with 6 μm spatial resolution and the internal structure is clearly seen. Furthermore, we developed a method to measure an ant in-vivo. The ant was anaesthetized by chloroform and then it was inserted into the micron tube. The inside of the tube is kept in atmospheric pressure and enabled to measure in-vivo. There is a large difference on the images between the fixed ant and the living one. In the case of fixed ant, the brain shrank and something was washed out due to formalin-fixation. Because the CCD is sensitive to visible light, we also examined the capability of light micron-CT using visible red lights from an Al_2O_3(Cr) ruby scintillator and applied it to investigate a small red thick. Obscure images were obtained due to the dispersion of lights. The 3D micron-CT can provide cross sectional images of in-vivo samples with high spatial resolution and will be useful for biological studies.