Using list-mode data to compare scatter corrections in I-131 imaging

Gamma camera imaging of I-131 suffers from detection of Compton-scattered events. Many different methods of scatter correction have been proposed for lower-energy radionuclide (e.g., Tc-99m) imaging. Extension of these scatter corrections to I-131 imaging is not obvious and may not be simple, because a significant fraction of the detected scatter is due to gamma rays that have scattered in the camera-head. The authors acquired list-mode data (x, y and E) from a digital gamma camera and rebinned it in different ways to compare five different scatter-correction techniques: lower-window subtraction, upper-window subtraction, upper and lower window subtraction, linear dual photopeak, and nonlinear dual photopeak. A lower, Compton-window subtraction appears most stable, and perhaps best.<>