Design And Implementation Of In-vivo Small Animal Optical Molecular Tomography Imaging System

As a new medical imaging technology, optical molecular imaging has been extensively applied in the biomedical research with the advantages of high sensitivity, high contrast, noninvasive and low cost. At present, there are only few optical molecular imaging system products and foreign products accounts for the major share. Thus, it is extremely important to develop our own optical molecular imaging system with independent intellectual property rights. This paper developed an animal optical tomography imaging system(AOIS), which can accomplish the data acquisition and processing of the bioluminescence tomography and fluorescence tomography. The main works are shown as below:(1) Designed and built the hardware system of AOIS. It includes black box, excitation light source, filter, animal fixation device, CCD camera and lens. Through rotating the fixation device, the camera is able to acquire fluorescence images of the animal with different perspectives.(2) CT or MRI images would be used in AOIS for multimodal imaging. In CT image preprocessing, we proposed a fixed tube removal algorithm based on region scanning to segment the tube, and used Otsu algorithm to eliminate the air between the tube and animal's CT data. In MRI image preprocessing, we combined the Otsu algorithm with region area statistic algorithm to denoise and precisely obtained the animal's volume data.(3) A line enhancement algorithm based on hessian matrix is used to detect the brightness area in the fluorescence images and proposed a bidirectional neighbor average method to restore it. It improved the performance of surface light irradiance reconstruction.(4) Designed and developed the AOIS software system. The main functions in AOIS are: hardware system control, data acquisition, storage and analysis, CT and MRI images segmentation, light source reconstruction and display in volume data.(5) Designed an mouse experiment. Reconstructed the light source in the body of a mouse using data acquired from CCD and verified the reliability of the system and the feasibility of algorithm.AOIS is an optical imaging system based on the cellular, molecular or genetic level expression, which can accurately locate the light source in the body of small animal in vivo. It is an important tool for analyzing and detecting biological process such as the growth and metastasis of tumors and the expression of specific genes.