title: Computer-assisted morphometric analysis of renal radiation response.
abstract: A single x-ray dose of 1,200 to 1,600 rads to the mouse kidney is associated with definite morphologic alteration but minimal functional impairment at six months; this progresses to profound structural and functional impairment by one year after irradiation. Subjective morphologic assessment of renal damage at six months correlates well with total radiation dose, fractionation schedule and energy characteristics of the radiation beam but does not provide adequate quantitative numerical data for sophisticated statistical tests of significance or for comparisons of effect variability at given dose levels. This investigation assessed the applicability of computer-assisted morphometric analysis (CAMA) for quantitation of effects and in making statistical comparisons of significance between kidneys subjectively classified as to degree of histologic alterations. Images of renal cortex tubular nuclei from the various histologic grades were digitized, recorded and analyzed with the CAMA system. Results indicate that the reliability of specific grade assignment by CAMA for individual nuclei was inadequate but that separation of irradiated and unirradiated renal tissue (bivariate group means) was quite distinct and of high reliability. Differences were present among the four irradiated histologic grades, but they were not marked, especially among the three highest grades. More accurate quantitation of nuclear size variations was achieved, and chromatin textural differences were detected that were not apparent to the eye. Computer-assisted morphometric analysis appears to have a valuable application in the quantification and analysis of chronic radiation effects.
mesh_terms: D000818:Animals; D001284:Atrophy; D002467:Cell Nucleus / Q000648:ultrastructure; D003201:Computers; D007668:Kidney / Q000473:pathology / Q000528:radiation effects*; D007674:Kidney Diseases / Q000209:etiology / Q000473:pathology; D007684:Kidney Tubules / Q000473:pathology / Q000528:radiation effects; D051379:Mice; D011832:Radiation Injuries / Q000473:pathology*; D013997:Time Factors