Scatter fraction performance tests for positron imaging system with dual plane geometry

NEMA NU 2 and IEC 61675-1 standards are widely used for characterizing the performance of PET scanners. These documents specify procedures for acquiring and analyzing data by using standard phantoms and radio-sources. However, some dedicated PET systems, such as breast and prostate PET systems, have non-ring geometric design may not meet these standards. In this work, we proposed certain modifications to the NEMA NU 2 for analyzing the scatter fraction (SF) of a dual-plane positron imaging system reasonably. A projection-map with geometric compensation was performed instead of sinogram to get analyzed profile. Three methods to determine analyzed window (4 × FWHM, 40 mm width, and 14 mm width) were used to estimate SF. The effects of diameter and location of line source were also considered. Three diameters (0.6, 2, 3.2 mm) and nine locations of line source were set for GATE simulation. The equivalent SF of the dual-plane system was calculated as the area-weighted average of nine-position SF values. The results reveal that the presented method here can estimate SF value better, compared with the methods suggested by the standards.