There are circumstances in which, by assuming that a high proportion of the radioactivity in a biological specimen is associated with certain well-dispersed structures of simple shape, a relatively simple and effective objective analysis can be carried out. The usefulness of this type of restricted analysis has previously been severely limited by the requirement that all the profiles of interest should be of roughly the same size, which is rarely the case. A procedure is proposed which, by appropriately combining image spread functions for profiles of the same shape but of various sizes, allows realistic hypothesis testing in such circumstances. Details for the practical application of the method are offered and criteria for assessing the feasibility of applying the method in particular circumstances are discussed.
The necessary backup information to the method is supplied in the form of the derivation of the fundamental image spread function, the introduction of a coherent notation and reference data quantitatively describing the image spread around certain extended sources of simple shape.