Fig. 2

Scores plot and loadings plot from PCA. The plot on the left is the scores plot of samples grouped according to the first two components for PCA when all dogs are used. Each dot represents one CTPA slice from one dog. PCA achieved good separation between slices from the healthy and the diseased dogs, but failed to discriminate between diseased dogs with PTE and diseased dogs without PTE. The plot on the right is the loadings plot of the 22 statistical parameters in four directions for the first two principal components. This plot shows the relationship of the various texture features that were extracted from GLCM and applied in later classification analyses using PLS-DA and SVM. (Nomenclature for these features is given in Table 1)