Fig. 6.

Classification of veins and arteries using principal component analysis. (a) Scatter plot of data projections on first two principal components, showing partition estimate. The final result is found to be independent of initial partition. (b) 3D scatter plot showing vessel data against vessel diameter, baseline flow speed and [HbO] changes. All units are normalized. Projections in x-y and y-z are shown to aid visualization. (c) Resulting vessel classification mapped onto calibrated LSCI flow map. Yellow vessels are arteries and cyan vessels are veins.