Preliminary study for pixel identification on a modular gamma camera

High count rate gamma camera with independent modules

“…The presence of this dead space causes a degradation of the intrinsic spatial resolution in the PSPMTs peripheral area, due to the increased pitch for the boundary crystals, but it allows keeping under control the variations of the intrinsic resolution across the detector FOV, optimising the overall pixel identification [8]. Each PSPMT has been optically coupled to a scintillator array through Visilox V-788 optical coupling grease.…”

“…The 24 mm hole-length collimator is designed to ensure a one-to-one correspondence between the square holes and the crystals of the scintillation assembly. This solution allows a better signal-to-noise ratio and a better detection efficiency with respect to the use of a standard hexagonal hole collimator [8].…”

“…Evidently, in the M4 detector each PSPMT becomes an independent detector module [8]. This solution allows dividing the FOV of the M4 detector into four independent areas that acquire events in parallel mode, greatly enhancing the counting rate capability of the device.…”

“…The average counting rate over 300 s was measured placing each source in the centre of the FOV at a distance of 30 cm from the detector without using a collimator. solutions proposed [8] to optimise the light collection efficiency. This aspect is however outside the aim of this work that is mostly concerned in counting rate performance evaluation.…”

“…Our group has introduced a solution based on CsI(Tl) crystals integrated into a square hole tungsten structure [7], and has recently investigated to optimise their pixel identification in order to design a modular gamma camera [8]. The use of tungsten structure allows us to reduce the inter-crystal Compton scatter and eliminates the optical crosstalk, achieving an enhancement of the image contrast [9,10].…”