One of the main strengths of PET is its unique ability to provide quantitative information of positron-labelled biomolecules within a living animal. The small animal scanner is used at this institution to test new investigational, therapeutic and interventional strategies that are developed in animal models of human disease in order to better understand the physiological mechanisms of cancer.
In order to achieve these goals, we have used the microPET scanner, which is CTI Concorde’s dedicated small animal Positron Emission Tomography (PET) scanner based on the PET technology developed at UCLA by Dr. Simon Cherry and his group. Non-invasive, in vivo imaging with microPET allows serial and longitudinal studies to be performed in the same animal giving researchers the opportunity to follow a single animal over time and to monitor the effects of interventions on disease progression and outcome. microPET is also ideal for studying genetically modified animals and will therefore be a particularly valuable tool in animal models which exhibit high variability and in situations where a particular animal is unique or valuable.
The microPET is based on a unique detector system consisting of fiber-optic readout of lutetium oxyorthosilicate (LSO) scintillator elements using a compact position sensitive PMT. The Edmonton PET Centre has a microPET consisting of four rings of position sensitive scintillation detectors. Each ring of the R4 microPET contains 24 detector blocks. Each detector block is comprised of an 8 x 8 array of small lutetium oxyorthosilicate (LSO) crystals (2x2x10mm) coupled via optical fibers to a multi-channel photomultiplier tube. The detector ring diameter is 14.8 cm, the central port measures ~12cm with an imaging field-of-view of ~10cm transaxially and 8cm axially. The scanner has no septa and operates exclusively in a 3-D imaging mode. Included with each tomograph, in addition to the gantry, is a computer controlled animal bed, a removable point source holder for attenuation correction, a laser alignment system, a Pentium based computer, data acquisition electronics and software for data acquisition, data correction, image reconstruction, image display and simple image analysis. The microPET performs with approximately 2x2x2mm image resolution resulting in an improvement of volumetric resolution over existing clinical tomography of a factor of ten.