Hidex AMG well counters
Ole Lajord Munk, September 2020
For research purposes, we often supplement PET measurements for quantitative studies with automated or manual blood sampling. For automated sampling, we have four automated blood sampling system. Two Allogg ABSS that use a BGO crystal for efficient detection of radiation from PET tracers in the blood – these are mainly used for blood sampling in humans and pigs. We also have two SwissTrace Twilite Three with LYSO detectors that are MR compatible and can be used with an arterio-venous shunt in small animals to allow measurements without any blood loss. Blood is withdrawn using a one-directional peristaltic pump and allows a dense and continuous (1-second steps) measurement of the time course of the activity concentration in the blood; this is preferred when the tracer has very fast kinetics, e.g. for perfusion measurements. We use dedicated software to provide calibrated data, which is corrected for dispersion and delay caused by the tubes, to obtain true arterial time-activity curves. Alternatively, our experienced technicians can manually withdraw 1-2 mL blood samples by syringes every 5 sec. An advantage of manual blood sampling is that plasma samples can be extracted, which is required for tracers where activity concentrations are different in plasma and blood. Manual blood sampling is also required in metabolite analyses. Radioactivity concentrations of manual blood/plasma samples are measured using our three Hidex AMG well counters that handle multiple racks of 10 test tubes. All PET scanners are cross-calibrated with our blood sampling equipment to allow easy analyses when combining PET data and blood data.
Allogg automated blood sampling system