Novel Concept in PET Imaging

Positron Emission Tomography (PET) offers high sensitivity to a range of biological processes through the use of targeted radiolabeled probes. PET imaging can provide diagnosis for symptoms of diseases such as Alzheimers disease, head trauma, cancer, and stroke. In recent years, there has been considerable interest in non-invasive plant imaging using short-lived radio tracers, such as 18F and 11C. It aids in the investigation of the coordinated behaviors of metabolic and transport processes, and how it translates into the characteristic behavior of plants. The detector is demonstrably the limiting factor in the performance and cost of the PET systems. The goal of the proposed project is to use of continuous crystals coupled to a new photodetector technology, silicon photomultiplier (SiPM) for investigating PET modules that are suitable for plant imaging studies, dedicated organ imaging systems as well as eventually clinical imaging. The main innovation of the proposed detector design over previously investigated continuous detectors is its ability to achieve high sensitivity and high spatial resolution in a thick continuous detector. High performance and low cost are expected from the proposed detector design. The Phase I project was aimed at demonstrating the feasibility of the proposed detector design. Detectors with large imaging area 50mm x 50mm were successfully built by constructing an 8x8 element SSPM array (with 5mm x 5mm SSPM elements). The feasibility of a PET detector that involves light spreading amongst several SSPM elements for a scintillation event based on our 8x8 SSPM array was successfully evaluated and based on the results, the feasibility of Phase I was adequately demonstrated. The Phase II project will be aimed at design and build high performance SSPMs with high gain, excellent optical detection efficiency and low noise. Advance the PET detector design investigated in the Phase I effort (based on SSPM arrays and a continuous block of LYSO crystal) as well as design and build high resolution detector modules to create bench top PET systems for clinical and plant imaging studies and detailed performance of the system will be evaluated out in Phase II. Commercial Applications and Other Benefits: Over and above the use in nuclear medicine, the proposed technology will be useful in nuclear and particle physics, space research, homeland security, environmental monitoring and synchrotron studies.