Indices of cell atypia in urinary tract cytology.

A sample profile based on assessment of digitized cell images of normal (NEG), malignant (POS) and two classes of atypical (ATY I and ATY II) urothelial cells was established. Data distributed in a multidimensional feature space were projected into a two-dimensional display space using linear discriminant functions as composite features. Fitting of a polynomial led to the derivation of an atypicality index for each cell and to statistically clearly significant differences in the atypicality values for the four groups of urothelial cells. The application of these findings to patients' profiles will be examined in a subsequent communication.