Positron Emission Tomography Imaging
Facilities and Equipment
The rodent PET imager is GE eXplore Vista DR small animal PET scanner that is located in the IVISR in the Moores Cancer Center. It is designed to accurately quantify and visualize regional, time-varying distributions of positron-labeled radiopharmaceuticals. The ring-type gantry with an aperture diameter of 8 cm and effective transverse field-of-view of 6 x 4.6 cm is designed for mice and rats. The scanner is comprised of a gantry into which an animal imaging bed is inserted under computer control. The scanner uses 36 high spatial resolution, dual scintillators, depth-of-interaction detector modules resulting in a total of 6084 detector elements, a crystal array pitch of 1.55 mm, and 28.8 million lines of coincidence. The system provides a central spatial resolution of 1.6 mm (FWHM) and absolute central point source sensitivity of 4.0% in the 250-700 keV energy window. The system software allows static, dynamic, whole-body, list mode, transmission and blank acquisitions in the 3D mode. Image data analysis includes a 3D ROI tool and multimodality image viewing.
The strength of PET imaging is in the relatively preserved biochemical behavior of positron emitting radiotracers. In live and sedated animals, dynamic PET imaging can measure the time-dependent cross-sectional tissue concentrations of a radiotracer that can then be used for kinetic modeling. Static PET images can provide tissue and whole body biodistribution of radiotracers similar to that of autoradiography. PET provides an alternative to MR imaging of receptor-based agents where the high dose required for adequate MR signal saturates the target. Specific services include:
- Imaging of receptor-targeted agents and gene reporters;
- Radiochemistry, tracers and validation (See Radiochemistry section)
- Metabolic imaging using F-18 FDG;
- Measurement of tumor biochemistry and/or physiology via kinetic modeling (see Kinetic Modeling section)