Controlling for cerebral atrophy in positron emission tomography data.

This article outlines a simple method for estimating the degree of cerebral atrophy and subsequent experimental control for the effects of cerebral atrophy on regional metabolic values measured with positron emission tomography. It is suggested that rather than correcting derived values for atrophy, less potential error is introduced by experimentally controlling for regional atrophy when possible. By treating the derived metabolic rates and the measure of atrophy as two separate variables, it is also possible to establish whether there actually is a demonstrable relationship between the two measures.