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Wu L.,Tianjin University | Zhao H.,Tianjin University | Zhao H.,Tianjin Key Laboratory of Biomedical Detecting Technique and Instruments | Yi X.,Tianjin University | And 3 more authors.
Guangxue Xuebao/Acta Optica Sinica | Year: 2013

A shape-based approach of image reconstruction under continues-wave mode is developed for diffuse optical tomography (DOT), which aims to simultaneously recover the smooth region boundaries and optical parameters of the biological tissue. The method is based on the spherical harmonics parameterization methodology and an assumption that different anatomical regions have their respective sets of the homogeneous optical parameter distributions. The boundary element method (BEM) is used for forward modeling, and a Levenberg-Marquardt optimization method is implemented for the inverse problem. The proposed scheme is validated using a domain with two heterogeneous inclusions, the shape parameters and the optical coefficients of the domains can be simultaneously reconstructing at different noise levels. And physical experiment on a phantom is also conducted to evaluate the performance of our method. The reconstructed results show that the methodology is very promising and of good convergence. The homogeneous optical parameters and shape parameters of each region can be reconstructed with good accuracy. Source


Wu L.,Tianjin University | Zhao H.,Tianjin University | Zhao H.,Tianjin Key Laboratory of Biomedical Detecting Technique and Instruments | Yi X.,Tianjin University | And 3 more authors.
Guangxue Xuebao/Acta Optica Sinica | Year: 2013

In view of low imaging resolution and quantitative accuracy in fluorescence molecular tomography (FMT) which are caused by the assumption of homogeneous optical structural background, and considering that the "coarse-grain" diffuse optical tomography (DOT) methodology based on region-labeling (region-based DOT) presents a promising tool of in vivo reconstructing background optical structure with the aid of anatomical a priori, an approach of region-based DOT guided FMT reconstruction algorithm under continuous-wave mode is developed for improving sensitivity of FMT. Numerical simulations are conducted on a region-labeled three-dimensional (3D) digital mouse atlas. The reconstructed fluorescent yield image with optical structural a priori information provided by region-based DOT algorithm is compared with the results with accurate optical structural background and hypothetical homogeneous background, respectively, to investigate the performance of this method. Physical experiments on a phantom are also conducted to assess this methodology. Our simulated and experimental reconstruction results indicate that this region-based DOT guided FMT approach can significantly improve the sensitivity of FMT, as well as its imaging resolution and quantitative accuracy. Source


Wu L.,Tianjin University | Zhao H.,Tianjin University | Zhao H.,Tianjin Key Laboratory of Biomedical Detecting Technique and Instruments | Yi X.,Tianjin University | And 3 more authors.
Guangxue Xuebao/Acta Optica Sinica | Year: 2013

A region-labeling approach of image reconstruction under continuous-wave mode is developed for "coarse-grain" diffuse optical tomography (DOT). The method is based on the framework of the pixel-based DOT methodology and on an assumption that different anatomical regions have their respective sets of homogeneous optical parameter distributions. The proposed scheme is validated using a three-dimensional (3D) digital mouse atlas, the optical parameters of the organs could be simultaneously reconstructed at 60 dB, 40 dB and 20 dB noise levels. Physical experiments on a phantom are also conducted to evaluate the performance of the method. The reconstructed results show that the region-labeling DOT solution greatly improves the ill-posedness of the inverse problem as well as the imaging resolution and quantitative accuracy by reducing the number of unknowns to be reconstructed. The homogeneous optical parameters of each region can be reconstructed from noisy data. Source

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