Abstract
Scintiscanning is a technique widely employed in nuclear medicine for detecting cancer and other lesions. This paper deals with scanning processes from the probability theory viewpoint.
In order to evaluate the fidelity of the scintigram, the coefficient of variation ε(n)=σ(n)/E(n) is used; σ(n) is the standard deviation, and E(n) is the expectation of the imaging pulses n(t). It was confirmed experimentally that n(t) is a Poisson process, so that in the conventional constant speed brain scanning ε(n) may vary significantly within the cold area, a very important area for analysis.
Based on the fact that the fidelity should be improved by maintaining the coefficient of variation constant, the isocount scanning was devised and realized. By this method, ε(R)=1/√N, where N is a preset constant, is independent of the count rate R over all the observed plane.
This scanning method has been applied to the brain in the clinic of our coworkers.
