D. Vozza et al., AN IMPROVED MODEL FOR THE ENERGY RESOLUTION OF MULTICRYSTAL ENCODING DETECTORS FOR PET, IEEE transactions on nuclear science, 44(2), 1997, pp. 179-183
Recently, we have shown that the program DETECT provides a realistic p
latform to model the performances of scintillation counters with geome
tries as involved as that of the EXACT HR PLUS, a state-of-the-art pos
ition and energy encoding EGO detector manufactured by Siemens-CTI for
positron emission tomography (PET), In this paper we present the resu
lts of new simulations of this block's performances, updated to includ
e the nonproportionality of the scintillation response of EGO and the
statistical noise from photoelectron amplification in photomultiplier
tubes (PMT's), The updated model accounts for the crystal-dependent en
ergy resolutions observed with 511-keV photons in the detector with ex
cellent accuracy, Measured and simulated resolutions are shown to agre
e within -1 to 4%, with an average absolute difference of 1% over the
entire block. The impact of the nonproportional scintillation response
of EGO on the energy resolution is shown to be relatively small compa
red to that of the amplification noise in the four PMT's reading out t
he block.