AUTOMATED TEXTURAL ANALYSIS NUCLEAR CHROMATIN - A MATHEMATICAL MORPHOLOGY APPROACH

Nuclear grading of neoplasms has classically been involved in prognosi s and must be established by combining different parameters, such as t he textural pattern of chromatin, which is subjective and difficult to measure. Mathematical morphology (MM), a branch of mathematics dealin g with shapes, and, in particular, the so-called top hat transformatio n, provides us with a helpful tool for quantitative assessment of chro matin texture. A sequence of MM operations (the top-hat transformation ) was applied to Mayer-hematoxylin-stained cytologic smears made immed iately after surgical removal to obtain a series of images at differen t levels of a granulometric chromatin fractionation. These images are related to size (n = 1, 2, 4, 6 and 8) of a structure element that per forms these operations. A skeletonization of the intergranular area at level 4 was also performed to provide a shape-related image of chroma tin grains. Using these granulommetric images as a starting point, rue defined a series of variables: TH(n) as the granulometric area at top -hat level n; GAD(n) as the grain-associated density at level n; THIOD (n) as the integrated optical density of the granular fraction at leve l(n); GIOD(n) as the grain-integrated optical density at level n; CP a s a chromatin texture variable, chromatin pattern, that estimates the granular versus dispersed aggregation pattern; and CB, a shape descrip tor that estimates the roughness of the isolated chromatin grains and is expressed as a coefficient related to the number of branches of the intergranular skeleton. The operation provides a set of variables des criptive of a wide range of chromatin texture properties. Therefore, i t could successfully contribute to a better and a more objective metho d of establishing the nuclear grade as well as of supporting future ex pert systems for diagnosis in pathology.