objective(s): in spect, the sinogram contains scatter and lack of attenuated counts that degrade the reconstructed image quality and quantity. many techniques for attenuation and scatter correction have been proposed. an acceptable method of correction is to incorporate effects into an iterative statistical reconstruction. here, we propose new maximum likelihood expectation maximization (mlem) ...

introduction: scattered photon is one of the main defects that degrade the quality and quantitative accuracy of nuclear medicine images. accurate estimation of scatter in projection data of spect is computationally extremely demanding for activity distribution in uniform and non-uniform dense media. methods: the objective of this paper is to develop and validate a scatter correction technique ...

Introduction SPECT projections are contaminated by scatter radiation, resulting in reduced image contrast and quantitative errors. Backscatter constitutes a major part of the scatter contamination in lower energy windows. The current study is an evaluation of the effect of backscatter material on FWHM and image quality investigated by Monte Carlo simulation. Materials and Methods SIMIND program...

Recent vector supercomputers provide vector memory access to "randomly" indexed vectors, whereas early vector supercomputers required contiguously or regularly indexed vectors. This additional capability, known as "hardware gather/scatter," can be used to great effect in general sparse Gaussian elimination. In this note we present some examples that show the impact of this change in hardware on...

introduction: scatter radiation is one of the major sources of error in nuclear medicine data processing. different methods of scatter correction have been introduced in order to improve the quality of data. however the best method is to avoid recording of scatter photons in acquisition. the only difference between scattered and non-scattered photons is the energy. pulse height analyzer is the ...

introduction spect projections are contaminated by scatter radiation, resulting in reduced image contrast and quantitative errors. backscatter constitutes a major part of the scatter contamination in lower energy windows. the current study is an evaluation of the effect of backscatter material on fwhm and image quality investigated by monte carlo simulation. materials and methods simind program...