Performance evaluation of the plate and array types of NaI(Tl), CsI(Tl) and CsI(Na) for small gamma camera using PSPMT

The intrinsic performances of the plate and array types of NaI(Tl), CsI(Tl) and CsI(Na) were measured to evaluate the characteristics of the popular scintillators employed for the development of small gamma cameras. Sensitivities, energy resolution and spatial resolution of the six scintillators, optically coupled to a Hamamatsu R3941 PSPMT, were measured for 140 keV using a gamma camera developed in the authors' laboratory. All the array type scintillators presented good spatial resolution (<2 mm) and the plate type scintillators provided better sensitivities than the array type scintillators. NaI(Tl)-plate showed the best sensitivity and energy resolution (16.8%) but the worst spatial resolution (1.3 mm) but the worst sensitivity. Among the plate type scintillators, CsI(Tl) provided good sensitivity and energy resolution (18.2%) close to the plate type scintillators with modest sacrifice in spatial resolution.