Morphology

Abstract

One of the major limitations in understanding the morphological changes that occur during atherosclerosis initiation, progression and regression, has been the relative lack of precise quantitative methods for establishing the extent, severity and topographical distribution of lesions. The most commonly used methods for determining atherosclerosis involvement within an arterial segment have been based on visual estimation. Atherosclerotic arteries, for instance, have been graded on arbitrary sliding scales representing increasing involvement, i.e., grade 1, 2, 3, 4, etc, relative descriptions, i.e., mild, moderate, severe, etc., on estimates of percent surface area containing lesions, and on the basis of percent “lumen stenosis” from cross-sectional histological slides. These methods are adequate for testing hypotheses that are aimed at determining large differences in the amount of atherosclerosis either between or among groups or within individual groups of subjects. However, these methods are considerably less sensitive in describing smaller or more subtle differences.