Micro-SPECT combined with 3-D optical imaging

A resolution enhanced NaI(TI)-scintillator micro-SPECT device using a pinhole collimator geometry has been built and tested with small animals. This device was constructed based on a depth-of-interaction (DOI) measurement using a thick scintilator crystal and a position sensitive PNIT to measure depth dependent scintillator light profiles. DOI measurement eliminates the parallax error that degrades the high spatial resolution required for small animal imaging. This novel technique for 3-D gamma-ray detection was incorporated into a micro-SPECT device and tested with a Co-57 source and Tc-98m-MDP in mice. We are now investigating the combination of micro-SPECT with 3-D optical imaging. so that the interaction of different biological aspects can e studied by each technique. A simple application permits a 3-D reconstruction of the animal ' s skin surface thus enhancing visualization and making possible depth-dependent corrections and a quantitative description of biological processes can be achieved. The combination of micro-SPECT and 3-D optical imaging, including bioluminescence 3-D reconstruction, opens new avenues in multi-modality imaging for biology and medicine.