Automated histomorphometry of interstitial reactions in the heart

A method is presented suitable to measure changes in area densities of the total Sirius red-stained interstitial tissue in longitudinal sections of rat hearts by means of computer-aided image analysis considering at the same time the behavior of six regions and changes in the percentage of thick connective tissue fibers in the total interstitial tissue. Verification tests were directed to the influences of preparation, adjustment of the grey-level thresholds, and identification of the various regions, to marginal conditions of measurement and the investigators. The reliability of the method with acceptable total errors is demonstrated.