Atherosclerosis is the leading cause of death for individuals in the United States and in all western countries. As noted, atherosclerosis appears to begin with the transport into and accumulation in the artery wall of low-density lipoprotein cholesterol (LDL) under conditions where blood LDL concentration is high and eventually develops into lesions. In previous work, our group developed models of water and macromolecular transport for the arteries. We predicted the 3-D distribution of macromolecular concentration in vessel walls with our theory. All heretofore experiments of the rate of growth of isolated tracer spots in vessel walls shined light through the vessel wall and, as such, obtained 2-D data corresponding to the projections of the tracer distribution onto a plane parallel to the endothelium. Our theory did an excellent job of predicting the growth of these projections. By scanning many thin sections through the sample with confocal microscopy, we have built up clean three-dimensional images of the tracer spots in blood vessel walls as a function of time between tracer injection and animal sacrifice. In order to best compare the data with the theoretical predictions, one needs to know the experimental origin of the 3-D coordinate system and the tilt of the experimental endothelial plane. By using 3-D interpolation to adjust the location of the origin and the tilt of the endothelial plane for the experimental 3-D images, we use Bremerman's method to find the most unbiased comparison of theory with experiment. We analyze how well the theory does when confronted with these 3D data.