title: A regularized deconvolution-fitting method for Compton-scatter correction in SPECT.
abstract: A method is presented for estimating the Compton-scatter component within the photopeak for local energy spectra measured by an Anger camera in SPECT. Assuming that the measured energy spectrum is the source scatter energy distribution convolved with a known camera energy-resolution function plus an unscattered spectral component, a least-square inverse operation is performed to recover the source scatter distribution. Since this inverse operation is ill-posed, the regularization technique is applied for stabilization. With the method, scatter fractions similar to those from polynomial spectral fitting (PSF) have been observed for experimentally measured, high-count data with a hot (Tc(99m) or I(131)) sphere in a cold cylinder, and the inverse (Tc(99m) only). The method is also less sensitive to the width of the fitting window. A regularization parameter from 1 to 10 is recommended for practical cases. The shape of a recovered source scatter distribution matches that determined by a high-resolution semiconductor-detector measurement as well as by Monte Carlo simulation.
authors.affiliation: Michigan Univ., Ann Arbor, MI.
authors.forename: X
authors.initials: X
authors.lastname: Wang
authors.forename: K F
authors.initials: KF
authors.lastname: Koral