A feasibility study using Trans-PET? BioCaliburn? LH in in vitro study: Performance characterization of detection limit and quantitative accuracy

摘要

In this work, we have characterized the detection limit and quantitative accuracy of the Trans-PET? BioCaliburn? LH system, in order to evaluate the feasibility of using small animal PET in in vitro studies. An in vitro cell uptake experiment with radioactivity lower than 1 μCi was performed with Monte Carlo (MC) simulation and then verified in real world experiments. Radioactivity concentrations ranging from 1 Bq to 10000 Bq for single-source and 10 Bq to 500 Bq for multi-source were used to determine the detection limit in Monte Carlo simulation experiment. For the same purpose in the real world cell experiment, the number of cells ranges from 50 to 105. The quantitative accuracy was verified by comparing PET image data with the true value (Monte Carlo simulation) and γ counter data (cell uptake experiment). The source with radioactivity of 1 Bq in single-source test and the source with radioactivity of 50 Bq in multi-source test can be visualized, as well as wells with the cell number above 500. The FDG retention determined by small animal PET and the γ counter showed a good linear correlation (r2=0.9997). High degree of correlation was also observed between the original radioactivity and the ROI value of the PET image (r2 =0.9970 in multi-source test and r2=1.0000 in single-source test). Hence, it is concluded that the small animal PET has sufficient sensitivity and desirable quantitative accuracy for the in vitro cell uptake experiment.