High-speed automated discrete blood sampling for positron emission tomography.

A computer controlled blood sampling system was designed specifically for rapid blood sampling for quantitative PET studies and uses solenoids that pinch silastic tubing, a roller pump and an inexpensive fraction collector. The controlling computer is an Apple II plus. The maximum sampling rate is one sample per 2 sec. Typical sample size is 0.90 +/- 0.02 g s.d. The loss of blood per sample is 2.6 ml. Tubing dead space is 1.2 ml. The response to a step change in activity between samples is 91% of the expected activity during high-speed sampling and 99% in the slower sampling mode. The major advantage of this device over flow-through detectors is that the blood is available for further processing to measure plasma or metabolite activities. This device has become a useful tool for quantitative PET studies, resulting in reliable sampling, lower radiation dose to personnel and fewer personnel necessary to conduct a study.