The Study On Diffusion Optical Tomography System Optimization&PET-diffusion Optical Fusion Imaging

Diffuse Optical Tomography(DOT),has been the most potential imaging diagnostic technology,for non-invasive,non-ionizing radiation functional imaging of tissue lesions,specifically for the detection and characterization of breast cancer or other soft tissue lesions based on differences in hemoglobin.The thesis introduces a diffuse optical tomography instrument which collects the system performance optimization,quantitative compensation,multi-spectral imaging and PET-DOT fusion imaging.The main work as follows:1.Performance optimization.The performance optimization of DOT system is divided into hardware and software part.The first part hardware optimization including noise optimization and the improvement of signal to noise ratio.The experiment results prove that the noise(dark current)optimization improves the imaging accuracy,on the other hand,the low-frequency modulation makes the signal-to-noise ratio increased from 36 d B to56 d B,the experiment discussion part give an engineering modulation reference frequency.The second part software optimization focus on the initial optical parameters' optimization,which is mainly reflects the the accuracy of the reconstruction position and the inhibitor to the boundary artifacts.2.Quantitative reconstruction & Multispectral imaging.The ill-posed of DOT inverse problem makes it difficult to recover the optical coefficients quantitatively.The thesis proposes to combine the quantitative phantom and the correction method based on homogeneous phantom.In order to evaluate the systemic quantitative reconstruction,designing a series of experiments.The experimental results show the quantitative of error is up to 9%.In order to obtain the absorption spectra of oxygenated hemoglobin and deoxyhemoglobin,designing the blood in vitro experiments between 660 nm and 850 nm.3.PET-DOT fusion imaging.The significance of PET-DOT joint imaging is to locate the tissue lesions accurately;Moreover,PET's unique metabolic imaging joint the DOT chromophore imaging has potentiality to predict the possibility of the metastasis.In order to verify that PET-DOT can achieve the same-machine fusion imaging,this thesis proposes a registration method and verifies its feasibility by using the phantom experiment.Then the PET-DOT fusion imaging on mice demonstrates that PET-DOT fusion achieve the information mutual.