Corrections for accidental coincidences and attenuation in maximum-likelihood image reconstruction for positron-emission tomography.

Politte, D G; Snyder, D L · IEEE Trans Med Imaging · 1991

basic_science · Level V

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Abstract

Reconstruction procedures that account for attenuation in forming maximum-likelihood estimates of activity distributions in positron-emission tomography are extended to include regularization constraints and accidental coincidences. A mathematical model is used for these effects. The corrections are incorporated into the iterations of an expectation-maximization algorithm for numerically producing the maximum-likelihood estimate of the distribution of radioactivity within a patient. The images reconstructed with this procedure are unbiased and exhibit lower variance than those reconstructed from precorrected data.