EFFECTIVE HALF-LIFE ESTIMATION - BAYESIAN SOLUTION

Estimation of the effective half-life, i.e. the time during which the activity within a region of interest falls to half of its original val ue, is a task often met in nuclear medicine applications. Usually, the estimation is based on the least squares (LS) fit of a straight line to the observed data expressed in semi-logarithmic coordinates. Such a solution is susceptible to measurement errors and provides little inf ormation on the estimate reliability. The Bayesian solution presented treats this estimation problem in a more efficient way by respecting t he well defined probabilistic problem structure and exploiting all inf ormation sources available. The efficiency claimed has been verified o n an extensive set of real life data related to diagnostics/therapy of thyroid diseases by I-131. An illustrative account of the experiments performed is presented.