Abstract:

This work describes the design and development of a novel Optical and Positron Emission Tomograph (OPET). OPET is a small animal murine (mouse) imaging device capable of imaging coincidence annihilation photons from radioactive Positron Emission Tomography (PET) tracers as well as optical Single Photon Events (SPEs) from bioluminescence sources. This instrument will aid biomedical researchers in their animal studies of human disease. This is a significant area of research as our expanding knowledge of the molecular interactions involved in human disease open new areas of investigation, such as personalized medicine and systems biology.

The aims of this work were to (1) Demonstrate that the same OPET detector modules are capable of imaging annihilation photons as well as SPEs, (2) Determine the effects of additional SPE signals and, (3) Perform online, real-time processing of coincidence annihilation photons and SPEs using Digital Signal Processing (DSP) methods.

The design and fabrication of the detector modules is described and the detector modules are characterized for the detection of SPEs. Signals from the detector ring are processed using a DSP unit which contains Analog-to-Digital Converters (ADCs) and Field Programmable Gate Arrays (FPGAs). The function of the DSP unit is controlled by PET and SPE model algorithms. The sub-components of each DSP algorithm are presented in detail along with the simulation results. Images acquired using the DSP model algorithms are presented and the performance parameters of the PET and SPE modes are discussed. This work ends with suggestions for future work required to prepare OPET for use by biomedical researchers.