Improvement of scanner performance by subtraction of Compton scattering using multiple energy windows.

Abstract

In many radiological imaging situations photon scattering leads to degradation of image quality. Energy discrimination can substantially reduce the effects of scatter in radiosotope imaging. However, with low energy isotopes such as 99TCm the limited energy resolution of scintillators allows only imperfect discrimination against scattered photons. With only a single energy channel available in a rectilinear scanner or gamma camera, a choice must be made between (a) the use of a high base-line energy, resulting in reduced sensitivity because of rejection of unscattered photons, or (b) a low base-line settng to maximize the countrate at the expense of image contrast and resolution. Sanders et al. (1969), and Beck and Harper (1966), have examined the effects of energy selection to establish the optimum window setting for 99Tcm brain scanning. Rollo and Schulz (1971), and Sanders et al. (1972), extended this work to include an assessment of the detectability of lesions by observe-performance measurements. The...