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

A new input function monitoring system has been developed using the GSO detector assembly for both PET and SPELT quantitative studies. Due to the rapid rise time of the pulse (about 10nsec), the coincidence time window can be reduced < 1nsec, reducing contribution of randoms associated with the high background activity surrounding the detector. Large light output improved the energy resolution of approximately 11% for 511keV photons, and 20% at 140 keV, as compared with the BGO detector, enabling the use of this system also in SPELT studies. The paired assembly of crystals provided the absolute sensitivity of approximately 7% for PET and 75% for PET tracers. Multiple arrangement of the paired detectors provided possibility of correcting for the transit time of radioactivity through the catheter tube. This study demonstrated that the present system can be of use in both clinical and small animal studies using SPECT and PET tracers.