MR-Compatible blood sampler for PET

An MR-compatible automatic blood sampler prototype for quantifying radioactivity in blood has been built and tested. The determination of the so-called input function is necessary to investigate the kinetics of the administered radiotracer in PET studies. The counting detector consists of 2 coincident LSO blocks (50times40times 30 mm³) coupled each to a single APD (10 times 10 mm² active area). Preliminary experimental and numerical results indicate that a specific sensitivity of about 1 cps / (nCi / ml) can be achieved. Tests during bimodal simultaneous MR/PET scans will be carried out in the future with a Siemens 3 T-Trio MR scanner and a brain PET insert.