APPLICATION OF RECONSTRUCTION-BASED SCATTER COMPENSATION TO TL-201 SPECT - IMPLEMENTATIONS FOR REDUCED RECONSTRUCTED IMAGE NOISE

Scatter compensation in T1-201 single photon emission computed tomogra phy (SPECT) presents an interesting challenge because of the multiple emission energies and relatively large proportion of scattered photons , In this paper, we present a simulation study investigating reconstru cted image noise levels arising from various implementations of iterat ive reconstruction-based scatter compensation (RBSC) in T1-201 SPECT, A two-stage analysis was used to study single and multiple energy wind ow implementations of reconstruction-based scatter compensation, and R BSC was compared to the upper limits on performance for other approach es to handling scatter. In the first stage, singular value decompositi on of the system transfer matrix was used to analyze noise levels in a manner independent of the choice of reconstruction algorithm, providi ng results valid across a wide range of regularizations, In the second stage, the data were reconstructed using maximum-likelihood expectati on-maximization, and the noise properties of the resultant images were analyzed. The best RBSC performance was obtained using multiple energ y windows, one for each emission photopeak? and RBSC outperformed the upper limit on subtraction-based compensation methods. Implementing RB SC with the correct choice of energy window acquisition scheme is a pr omising method for performing scatter compensation for T1-201 SPECT.