J Med Phys Close
 

Figure 1: A transaxial slice from the cold sphere region of a reconstructed Jaszczak phantom with filtered backprojection reconstruction and Butterworth prereconstruction filter (order: 6 cutoff: 0.55) is illustrated. The count profile illustrates increased counts at the periphery compared to the center due to the greater distance the photons emitted from the central region must travel on average before reaching the detector through the attenuating medium than the periphery

Figure 1: A transaxial slice from the cold sphere region of a reconstructed Jaszczak phantom with filtered backprojection reconstruction and Butterworth prereconstruction filter (order: 6 cutoff: 0.55) is illustrated. The count profile illustrates increased counts at the periphery compared to the center due to the greater distance the photons emitted from the central region must travel on average before reaching the detector through the attenuating medium than the periphery