| 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 as a new nondestructive detecting technology of high spatial resolution has been greatly improved in recent decades. Micro-CT has been put into use in many areas, such as bone structure analysis, blood vessel analysis of rat liver, the study of adiposity treatment, etc. 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 a digital radiography system has been described. The digital radiography system is a fiber-optics taper-coupled imaging system based on two CCD arrays. The system showed its advantage in terms of its properties of spatial resolution and the measurement of modulation transfer function (MTF), noise power spectrum (NPS) and noise equivalent quantum (NEQ).A micro-CT system is designed based on the digital radiography system. The hardware of the micro-CT system includes the digital radiography system, rotating stage and its controller, image capture and processing system, etc. The rotating stage of 3-degrees is controlled by a step motor. Horizontal translation, vertical translation and rotation is used to align the rotating axis and image center, choose the magnification factor and rotate the models respectively. A simple method for the align of rotating stage and image center is presented. The software of the micro-CT system includes the realization of the image pre-process and 3D reconstruction. The FDK algorithm is token as the 3D reconstruction algorithm, which can ignore the effect of cone-angle.The micro-CT system is used to reconstruct a Lucite sample first and the result shows that the system has a high precision, the relative error of reconstruction is under 0.6%. Then the micro-CT system is used to image a nude mouse successfully.
|
PDF Full Text Request