Fig. 2. A probability-density contour map of the carotid artery in Fig. 1. The density contours (in SD's) are calculated from near-IR spectra using the BEST algorithm. A crosshair can be positioned anywhere on a contour map and used to select full spectra for analysis, to calculate a chemical composition at the selected location, or to give a distance from the calibration samples in multidimensional BEST SD's.