Multi-modality CT-PET-NIR fluorescence tomography

We report the development of a multi-modality NIR fluorescence tomography system. Existing small animal imaging techniques of micro CT and micro PET are utilized to acquire the animal geometry from which a finite element description of animal body is created. Non-contact frequency domain fluorescence boundary measurements are acquired by positioning a scanning NIR laser source and a gain modulated intensified CCD camera in a rotational mode about the animal bed used in the CT/PET scanner. Optical imager is aligned with the PET gantry to enable seamless imaging. Fluorescence image reconstruction is performed with the help of a novel radiative transport theory based algorithm. We demonstrate 3D image reconstruction of a multi-modality CT/PET/fluorescence target implanted within the torso of a nude mouse.