An analysis of correction methods for emission contamination in PET post-injection transmission measurement

The authors have evaluated and compared three techniques for estimation of emission contamination in PET post-injection transmission scans (PITSs). For PET scanners with electronic windowing of events that intersect the transmission source locations, the emission contamination can be estimated by: (1) the emission data taken either before or after the transmission scan, using a sinogram window mask to correct for the rod position and window width; (2) the emission data taken concurrently with the transmission data and a similar sinogram window mask; (3) utilizing a windowed transmission scan with cold rods, or “mock” scan. These techniques have been evaluated with phantom experiments to simulate a wide range of residual activities and object sizes