Optimization of a contrast enhanced micro-CT in a hybrid fluorescence / x-ray tomography system for small animal imaging

Dual modality imaging is an emerging and fast developing technique due to its advantage in providing complementary anatomical and functional information. Moreover, in the specific case of Fluorescence Molecular Tomography (FMT), knowledge of the detailed anatomical structure of the subject can be very helpful in improving 3D fluorescence reconstruction. In the framework of the FMT-XCT European Project, aimed at the development of a hybrid tomographic x-rays and optical prototype, we propose in this paper a specific micro-CT system, appropriate for small animal imaging and satisfying the needs of the dual-modality approach. The system is minimizing X-ray interference with optical components, and offers improved contrast between internal tissues to be used as prior information for the FMT inversion procedure. For the contrast enhancement goal, a dual-energy approach has been investigated and evaluated. System configuration, acquisition protocol and processing algorithms are described in the following sections. Software simulation has been used for the optimization of the imaging configuration and the suggested specifications and the resulting imaging performances are experimentally validated.