The three cell types examined in the study fell into four distinct nuclear shape categories. Category 1 cell nuclei were slender, with marked concavity. Category 2 cells had a slight concavity and were bulky. Based on these shapes, the first two categories are termed mushroom cap morphology. (The Category 2 mushroom cap morphology was the most common nuclear form seen in all three cell types.) Category 3 nuclei were mostly convex in shape, while Category 4 nuclei were irregular and distorted in shape, (see 3-D renderings in Figure 1).
Importantly, cells drawn from the cancerous cell line showed the largest fraction of irregular, Category 4 and Category 2 nuclei and the smallest fraction of nuclei with a Category 3 convex shape. The malignant cells also displayed the greatest shape heterogeneity within Category 4. The fibrocystic cell sample contained the largest fraction of Category 3 and the lowest fraction of Category 1 nuclei. The largest overall shape heterogeneity with respect to the four shape categories occurred in the normal cells.
Cell and nuclear volume were observed to increase as one moves from normal to fibrocystic to malignant cells, though fibrocystic cells had, on average, the largest nucleus-to-cytoplasm volume. Textural distinctions among cells and arrangement of chromatin were also observed. In all, the team computed 42 distinct 3-D morphological and textural descriptors of cellular and nuclear structure. Cell-CT technology is able to resolve cell features down to less than a half micron.
Study co-author Roger Johnson, Research Laboratory Manager at the Center for Biosignatures Discovery Automation, stresses that the subtle nuclear differences observed, particularly for the malignant cells, would likely have been missed had the samples been examined with conventional 2-D imagery. As a resu
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Arizona State University