METHODS

With the assumption that Compton scatter may be modeledasaconvolutionofthenonscatteredprojection data with an exponential function, deconvolution of this function from the total (scatter+ nonscatter) data yields the compensated true data. To determine the parameter values for the exponential function, a Monte Carlo simulation was performed yielding separately a non scatter and a scatter image for SPECT acquisitionof a line source with radius 0.25 cm, length I1. 0 cm, in a water filled phantom with radius II. 0 cm, length II. 0 cm. Results obtained using line-source data are signifi cant since the one-dimensional (single slice) projection response to a line source is equivalent to the system re sponseto an impulsefunction. It followsthat the system response to any arbitrary source distribution may be represented as a linear combination of the system re sponse to line sources. This follows from the fact that