Design analysis of a high resolution detector block for a low cost small animal positron emission imaging system

Computer simulations have been run to evaluate and optimize a high resolution block detector design for a low cost small animal PET system. The proposed detector module would be made using GSO crystals instead of the more commonly used scintillator, BGO. The main advantage of using GSO instead of BGO is that recent samples of GSO have been measured to produce at least twice the light output of BGO. Because of the additional light, it should be possible to develop a practical 6×14 crystal GSO detector module. This is approximately a factor of two greater than the number of crystals which are currently being decoded using BGO. Using the design the authors propose, the intrinsic spatial resolution of the detector module should be <2.5 mm FWHM in both dimensions and provide adequate sampling when assembled in a ring configuration to meet the Nyquist sampling requirements for 3 mm FWHM image resolution. The system the authors propose would have a 15.6 cm detector ring diameter, an 8 cm in plane field of view, and a 2.1 cm axial field of view. The proposed system would consist of 12 detector modules and would require only 24 dual photocathode PMTs and ~127 cc of GSO