Design And Implementation Of A Micro-CT System For Small Animals'Study

Computed Tomography(CT) is one of the key technologies in contemporary medical image and nondestructive testing, the use of medical CT is evolving especially rapidly. Small animal model has been a basic tool in human disease research. Different instruments specially for small animal image has appeared in recent years. Micro-CT imaging is an oncoming CT technology. With micron spatial resolution, it can get complex internal structure of the 3D information by completely nondestructive method with lower radiation and more fast reconstruction algorithm, which make the systems perfect for scanning small samples in medical images. As the development of computer science and information technology, micro-CT will be the typical research methods.The dissertation focuses on the design and application of micro-CT system. A design scheme of a micro-CT system based on the theory of imaging and reconstruction of CT system. The key components of this micro-CT system are X-ray source and flat-panel detector, and it includes horizontal table controlling system and image acquisition and processing system. X-ray source and detector stay still when image capturing, and sample is put on the center of rotatable table. The operation of the whole system is controlled by the control center, it controls the X-ray source, the data acquisition of detector, it also sends instructions to the motor driver, driving the rotatable table and the horizontal table. The amplification ratio of this micro-CT system is between 1.22~2.72, the repeat positioning accuracy is 0.003 degree and the step angle of rotation is 1 degree.We have used this micro-CT system to sample and reconstruct a small sample, the FDK algorithm is token as the 3D reconstruction algorithm, which can ignore the effect of cone-angle. Slice images and visualization of three-dimensional datasets showed the good performance of the micro-CT system and the capability of scanning small samples with high resolution. Then the micro-CT system can be used to image a small animal successfully.