A scatter correction method for Tl-201 images: a Monte Carlo investigation

Results from the application of a modified dual photopeak window (DPW) scatter correction method to Monte Carlo simulated Tl-201 emission images are presented. In the Monte Carlo investigation, individual simulations were performed for six radiation emissions of Tl-201. For each emission, point sources of Tl-201 were imaged at various locations in a water-filled elliptical tub phantom using three energy windows: two 12% windows abutted at 72 keV and a third 10 keV window placed to the right of the photopeak window. The third window was used to estimate the spilldown contribution from the Tl-201 gamma rays in each of the two photopeak windows. Using the corrected counts in these two windows, the DPW method was applied to each point source image to estimate the scatter distribution. Application of this modified version of DPW resulted in an approximately six-fold reduction in the scatter fraction and an excellent agreement of the shape of the tails between the estimated scatter distribution and the truth