The preclinical imaging facilities are staffed in assisting investigators with obtaining the necessary authorizations for animal and radioactivity usage; training new investigators on the operation and analysis of imaging systems; assisting with animal preparation, including minor surgery and catheterizations; operation and maintenance of the gas anesthesia systems, monitor animals during imaging and recovery; operation of microPET systems, including calibration tests, image creation and quality control; operation of the microCT system, including any attenuation correction for PET images; reconstruction of images for microPET and CT; archiving and verification of the availability of images; maintain and report of records required by various authorization committees.
The imaging lab in the Radu/Czernin suites is equipped with a Genisys PET (Sofie Biosciences) and an Inveon microPET (Siemens). The Genisys4 is a small bench-top preclinical PET scanner designed to enable imaging in biology, biochemistry and pharmacology laboratories and imaging centers. It consists of 4 panel detectors arranged in a box geometry. The spatial resolution is 1.35 mm in full width at half maximum. The scanner features a real time respiratory monitoring system with monitoring and control of anesthesia, and temperature for biologic stability and animal safety. Anatomical reference images are provided via a combination of x-ray projections, photographic images and a mouse atlas. The Inveon has an active FOV 12 cm in the transaxial and 12 cm in the axial direction. Reconstructed image resolution is ~1.75 mm using filtered backprojection, ~1.2 mm using iterative reconstruction. For the 250-700 keV energy window, the sensitivity is ~10% for the Inveon. The Inveon is often used in conjunction with the microCT system described below, and co-registered and attenuation corrected microPET-CT images are routinely produced. An 8 node computer cluster aides in the image reconstruction of PET and CT data. Additional display and processing computers support customized framing sequences to match probe distribution kinetics over time.
The microCT System
A microCAT II (Siemens Preclinical Solutions) small animal CT system with a 10 cm detector capable of imaging a whole mouse in one view with excellent spatial resolution (50-400 mm) is available in our imaging facility. Imaging chambers are provided for all PET and CT imaging work to ensure proper heating, anesthesia and placement of the animals, since any object outside the CT 10 cm FOV would cause image artifacts. To facilitate use between microPET and microCT, an imaging chamber has been designed to work in both systems, providing a common imaging platform and hardware image registration.
All imaging data are created on the local imaging systems and archived through a central archival system developed specifically to handle any type of image data format. The preclinical imaging suite and the cyclotron facility are connected via a pneumatic tube to facilitate PET probe delivery.http://pet.ucla.edu/?p=924