Setting the standard for the accurate measurement of samples containing low level positron emitters

11/12/2015

Positrons are of increasing interest, not only because of clinical use in PET, but also in animal and human metabolism profiling. However, unlike PET QC measurement, the samples derived from metabolic studies are of very low level, due to the time taken to synthesize complex molecules and the duration of biological chemistry. This is where LabLogic’s Posi-RAM is in its element. Specifically designed to detect and measure these low level metabolites, it sets the standard in its field.

511KeV gammas that are produced in PET can be counted using a conventional single detector gamma counter, but considerable background and noise is also detected due to the inability to differentiate between true events (from the metabolite sample), cosmic rays and natural radioactivity such as K-40 in the glass. To overcome this Posi-RAM utilises two conventional separate BGO crystals with coupled PMT’s. Each detector collects events – a separate output from each PMT goes to a coincidence circuit that compares the timing of the event so only events observed at each detector within 26 nanoseconds are validated. This logic virtually eliminates noise and dramatically reduces background – ensuring reliable detection of even the lowest level metabolites.