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The dual-modality systems combined fluorescence molecular tomography (FMT) and micro-computed tomography (micro-CT) can provide molecular and anatomical information of small animals simultaneously. Except for anatomic localization, micro-CT should also offer boundary of different organs as reconstruction priors for FMT, which is more challenging than acquisition of structural information. In this paper, we propose a framework to extract structural priors of a living mouse with micro-CT. The iodinated lipid emulsion contrast agent was adopted to enhance the contrast of the soft tissues of the mouse. Then organs in thorax and abdomen were segmented with different approaches depending on the characteristics of the organs. Bone, lung, heart, liver, spleen, and muscles were separately segmented. And the results were compared with that manually segmented. The Tanimoto coefficient and the relative volume difference of segmented slices were measured to be 91.28 ± 5.78 and 0.27 ± 3.15, respectively. In our simulation study of FMT reconstruction, the errors of measured position and concentration of the fluorophore with priors declined by 89.7% and 79.6% in thorax, as well as 80.8% and 78.3% in abdomen, respectively, compared with the results without priors. The proposed scheme will make FMT reconstruction much more reliable and practical in small animal study. [ABSTRACT FROM AUTHOR]

The combined system of micro-CT and fluorescence molecular tomography (FMT) offers a new tool to provide anatomical and functional information of small animals in a single study. To take advantages of the combined system, a data preprocessing method is proposed to extract the valid data for FMT reconstruction algorithms using a priori information provided by CT. The boundary information of the animal and animal holder is extracted from reconstructed CT volume data. A ray tracing method is used to trace the path of the excitation beam, calculate the locations and directions of the optional sources and determine whether the optional sources are valid. To accurately calculate the projections of the detectors on optical images and judge their validity, a combination of perspective projection and inverse ray tracing method are adopted to offer optimal performance. The imaging performance of the combined system with the presented method is validated through experimental rat imaging. [ABSTRACT FROM AUTHOR]