Scatter compensation techniques for SPECT
Compton scattered photons included within the photopeak pulse-height window decrease the image contrasts of lesions. The use of NaI(Tl) as the primary detector for SPECT systems results in the inclusion of both scattered and nonscattered photons within the primary photopeak window. A compensation procedure is required to eliminate (or minimise) the effects of scattering from SPECT imaging. Furthermore, in the absence of an effective compensation procedure, the accuracy of the SPECT measurement is reduced. The effect of scatter on SPECT is reviewed, and the influence of scattered photons on the effective linear attenuation coefficient with multiplicative attenuation compensation methods is described. Criteria for evaluating scatter compensation procedures are proposed, and approaches to reducing the effect of scatter on SPECT imaging are described