Comparison of columnar and pixelated scintillators for small field of view hybrid gamma camera imaging

For intraoperative medical imaging, the development of small field of view (SFOV) hybrid gamma cameras is an expanding area of research. The performance characteristics of a new innovation combining both gamma and optical imaging in a co-aligned configuration, the Hybrid Gamma Camera (HGC) have been evaluated and compared. In this study the HGC was fitted with either 1500 μm thick columnar CsI:TI or 1500 μm thick pixelated GOS scintillators. The columnar CsI:TI scintillator has an intrinsic spatial resolution of 230 μm compared to 1090 μm for the pixelated GOS scintillator. The sensitivity at 140.5 keV of the CsI:TI was 40 %, however, for the GOS it was 54 %. The intrinsic spatial uniformity was comparable for both CsI:TI and GOS scintillators. There was a significant difference between the CsI:TI and GOS scintillators for count rate capability which was lower when using a GOS scintillator.