[On the application of the triple energy window method to the 201Tl imaging].

In the radionuclide imaging by 201Tl several K-X rays are acquired, so it is difficult to eliminate scattered photons in the acquired photons. This paper describes the limitation and efficiency of the triple energy window (TEW) method in the application of 201Tl myocardial studies. We evaluated the TEW method by simulations and the setting of the parameters in the TEW method were 20, 30 and 40% for the width of the main window, 3, 5 and 7% for the width of the two sub-windows. Moreover, the location of the main window was shifted by each 1 keV from 60 to 80 keV. Simulation results were evaluated with the mean square error between true scattered photons and estimated scattered photons. The results show that the mean square error was minimized when the widths of the main window were 20, 30 and 40%, and the centers of the main window were 66-68, 69-70 and 72-73 keV, respectively.