Imaging performance dependence on crystal absorption properties: the CRY018 and CRY019 comparison

A proper choice of the scintillation crystal can considerably improve the detector performance in nuclear medicine imaging. In this study two promising crystals, CRY018 and CRY019, are characterized in terms of spectrometric and imaging capabilities. Thanks to the same irradiation conditions, it has been possible to compare their performance for a wide range of energies (30 keV to 662 keV). They have high energy resolution (6.5% and 7.6% at 662 keV for CRY018 and CRY019, respectively), negligible light yield non-proportionality, good position linearity, and intrinsic spatial resolution less than 2 mm. In particular, the performance deviations could be explained from the different attenuation length (CRY018 depth of interaction is higher than CRY019 one, due to their different density).