PET-MOT - a novel concept for simultaneous positron and optical tomography in small animals

We present a Monte Carlo feasibility study of a device designed to simultaneously image positron labeled substrates and optical molecular probes in small animals such as mice and rats. The acquisition arrangement constitutes an entirely novel imaging system considering the dual-modality feature as well as the integrated non-contact optical detection principle. In our proposal, the optical scanner does not employ gantry-mounted CCD cameras for detecting projection data. Instead, it uses a cylindrical lattice of micro lens arrays which form an inner optical detector ring while PET detector blocks are mounted in radial extension. The most innovative aspect of the proposed design is the possibility to perform unified simultaneous acquisition, reconstruction, and tracer/molecular-kinetic modeling of dual-labeled emitters. Since regional distribution and time variation of the underlying multi-variate photon distributions are acquisition and subject specific and diversified by variations thereof, combined and simultaneous imaging carries advantageous potential for translational research. Further advantages are less subject encumbrance and identical imaging geometries. The proposed nuclear-optical tomographic imaging system might potentially foster the development of optical image reconstruction algorithms using PET images as a prior to quantify fluorescence and bioluminescence distributions in heterogeneous media in vivo.