Automated cell counting in tissue sections: a new approach by 'multiple grey-level analysis'.

A system is described for the automated quantitation in tissue sections of the follicular and stromal cell populations of the thyroid gland, using a computer-linked TV image analyser. The paper illustrates how the problems of variable staining intensity and clustering of images (nuclei) may be overcome by a novel approach, in which multiple analyses of each field are made at increasing grey-level thresholds, and then 'synthesized' by computer to give a composite image. Discrimination between cell (nuclear) types was by a single minimum width criterion. The results were highly reproducible and correlated well with counts obtained by a comparable manual method.