Morphometric quantification of atherosclerotic plaques by computer-assisted image-analysis of histographs.

A method is described for quantifying the amount of atherosclerotic plaque in collapsible blood vessels by a computer-assisted image analysis of cross-sectional contours traced under microscopic visualization. The digitized contours are processed using a computer program that transforms the irregular image of the collapsed vessel into an ideal geometry and then calculates in vivo linear and areal parameters, variables, and ratios. The analysis is based on conventional stereologic principles and utilizes relatively inexpensive and widely available equipment: microscope with drawing tube attachment, digitizing board, microcomputer, monitor, and printer or plotter. Some of the output data include the fraction of vessel lumen occluded by plaque, average thickness of plaque, the fraction of wall surface area covered by plaque, and the ratio of the vessel bore to vessel wall volumes. The error and precision of measuring lumen occlusion and plaque surface area are assessed.