Development of a GSO detector assembly for a continuous blood sampling system

A new input function monitoring system has been developed and evaluated using a GSO detector assembly for both PET and SPECT quantitative studies. Energy resolutions were 11% for 511 keV photons, 20% for 140 keV(Tc-99m) photons and 28% for 70 keV(Tl-201) photons, enabling the use of this system in SPECT studies. The paired assembly of crystals provided an absolute sensitivity of approximately 7% for PET tracers and 70% for Tc-99m and Tl-201 (SPECT tracers). Multiple arrangement of paired detectors would make it possible to correct for the transit time of radioactivity through the catheter tube. This study demonstrates that the present system can be of use in both clinical and small animal studies using SPECT and PET tracers.