A Portable and Accurate Radioactivity Meter for Online Measurement of the Arterial Blood Activity in Dynamic PET Imaging

In dynamic PET imaging, the temporal function of arterial blood activity is required for the absolute quantification of physiological parameters for the purpose of disease diagnosis and drug development. This work aims to design a portable meter to continuously and accurately measure arterial blood activity of small animals in dynamic PET studies. We used Monte Carlo simulation to determine the minimum thickness of crystals and the amount of SiPMs of two scintillation detectors. Then we assembled detectors with embedded processors that process signals and transmit data. Finally, a temperature control module was developed to avoid the large cooling system for a compact design of the meter. The overall size of the blood activity meter is 80 mm × 175 mm × 85 mm, achieving a relative error of 0.4636% within the regular dose range of an animal experiment. The temperature of the whole system remains between 24.78 °C and 24.94 °C for 12 hours of continuous acquisitions. Experimental results suggest that the proposed activity meter has the potential to measure animal blood activity once the arteriovenous shunt is built. The miniaturization and portability of the proposed activity meter enable users to place the meter as close as possible to the subject animal and reduce the blood loss of the animal.