Karyometry of pseudostratified, metaplastic and dysplastic nasal epithelium by morphometry and stereology. 1. A general model for automated image analysis of epithelia.
Nuclear enlargement, usually due to the existence of abnormally high DNA (ploidy) values, is one of the alterations most often encountered in pathological epithelia, especially in cancerous and precancerous states. Direct DNA measurements on microscopic sections are impossible, and karyometric studies must take the difficult stereologic problem of spheroid sectioning into account. A mathematical model is proposed to describe an aggregate of separate parallel anisotropic prolate spheroids of variable size and eccentricity. This model appears suitable for the study of epithelial nuclei. After a tentative estimation of the biopsy angle, the application of the model to nuclear profile measurements produces the stereologic data of the mean spheroid nucleus: major and minor axes (and their ratio), volume, surface area (and the V/S ratio), and numerical density. Considerable time may be saved by the use of an image analyser with a specific algorithm. Most of the steps are entirely automated, but the user retains the interactive choice of the nuclei to be studied, for instance by separating the different epithelial layers. The profile data are computer-filed and several programs can yield the stereologic estimations and plots of nuclear profile areas. Poolings of cases of similar histologic staging and nearly the same sectioning angle can be used for the profile area plots. The model has been applied to pseudostratified and altered nasal mucosa of nickel workers. The stereologic estimates, mainly the nuclear volume, correlate well with histologic gradings. The nuclear profile area plots are considered useful for an assessment of the nuclear polyploidism. The complete model should be applicable to many other types of functionally or pathologically altered epithelia, particularly for cancer and precancer screenings, when the use of sectioned material is a prerequisite.
D001330:Electronic Data Processing; D006801:Humans; D007620:Karyometry; D008433:Mathematics; D008679:Metaplasia; D008954:Models, Biological; D009297:Nasal Mucosa / Q000473:pathology*; D011123:Polyploidy