Design study of a novel dual-modality emission micro-imaging tomograph for radiopharmaceutical and bioluminescent/fluorescent molecular approaches

We have designed, simulated, and propose to construct a novel dual-modality (multi-)pinhole aperture micro-tomograph to image simultaneously and from identical projection angles in vivo distributions of bioluminescent and (near-infrared) fluorescent molecular markers and radiolabeled pharmaceutical distributions. Unified data acquisition and reconstruction is the main motivation given the long term objective of developing new tracer/protein-kinetic models for dual-modality/energy small animal imaging. In order to investigate the performance of the micro-tomograph, we have developed device-specific Monte Carlo simulation algorithms that solve physically exact photon path integrals through nonuniform tissue phantoms and have performed simulation studies for pre-construction evaluation of all considered pinhole apertures, scanning geometries, and camera specifications both for optical photons and for photons up to 600 keV. Two different tomographic device designs have found to be both sensitive and high specific with regard to the detected energy range of the emitted photons under different acquisition situations.