Preliminary performance of optical PET (OPET) detectors for the detection of visible light photons

The Optical Positron Emission Tomography (OPET) system will provide the capabilities of bioluminescence and PET modalities in one combined imaging system. Bioluminescence light emitted in vivo has a spectrum ranging from 550–700 nm. The optical photon signals detected are approximately two orders lower in amplitude and one order shorter in duration compared to scintillation light pulses from a 511 keV γ-event. In this study the performance characteristics of the OPET detectors for bioluminescence imaging were evaluated. The detection uniformity was measured for wavelengths between 400–700 nm and normalization maps were used to correct the acquired images. The spatial resolution along the transaxial and axial directions was 2.30 and 2.38 mm FWHM, respectively. The average dark counts for the detector was 76±30 cps at an ambient temperature of 20°.