The influence of backscatter material on 99mTc and 201Tl line source responses
SPECT projections are contaminated by scatter, resulting in reduced image contrast and quantitative errors. When tissue is present behind the source, some of the detected photons backscatter via this tissue. Particularly in dual-isotope SPECT and in combined emission-transmission SPECT, backscatter constitutes a major part of the down-scatter contamination in lower-energy windows. In this paper, t