Shape descriptors in diagnosis
Abstract
The aim of the study was to analyze the behaviour of the shape descriptors of cell nuclei comparing them with other parameters normally used in digital image analysis. The study was carried out in two steps: 1) Parameters of several different parameter sets (shape descriptors, invariant moments, parameters derived from the histogram and the co-occurrence matrix of the extinction values of the pixels and partially densitometric parameters) were compared with one another in five patient groups (colon carcinoma, colon adenoma, urothelial papilloma, prostatic carcinoma and macrophages in broncho-alveolar lavages). 2) The most important parameters of each set, detected by a factor analysis, were matched in a new general data base and newly analyzed. According to the results of these analyses, two main groups of shape descriptors can be postulated: the "key parameter" of the first group is the axial ratio (B/A), either calculated by the nonlinear least squares fit method or by a Fourier analysis. The "key parameter" of the second group is the bending energy. Additionally, a close correlation between the two parameters, axial ratio (B/A) and the second invariant moment (PHI 2), describing the nuclear texture, could be observed in each of the five patient groups.