Figure 1.
Representative CT lung volume characterized into parenchymal patterns by Computer Aided Lung Informatics for Pathology Evaluation and Rating (CALIPER).
It illustrates colored overlay in axial (A), coronal (B) and sagittal (C) sections with glyph (D) and 3D rendering (E). The color key for the seven patterns is also shown.
Figure 2.
1322 LTRC patients represented as glyphs.
The classified parenchymal patterns are represented in the indicated colors. The radius of the glyphs is proportional to the lung volumes; the COPD cases with extensive low attenuation areas likely due to emphysema are visually larger than more normal or fibrotic cases with considerable regions of reticular or honeycombing.
Figure 3.
The permuted dissimilarity matrix (1322×1322) representing the abnormality based pairwise dissimilarities (brighter the shade higher the dissimilarity).
The green blocks illustrate the first-pass clusters and the red diagonal blocks represent the final ten stratified clusters.
Figure 4.
The ten stratified groups of 1322 patients represented as glyphs.
The groups were the result of quantitative unsupervised clustering based on dissimilarity metric that captures the distribution of classified parenchymal patterns.
Figure 5.
The plot shows the mean population values of the semi-quantitative visual radiology scores (assigned by LTRC radiologist) for each parenchymal abnormality in each cluster.
The error bar is the standard error of mean of scores across the patients in the cluster.
Figure 6.
The cluster-specific mean physiologic measures (FEV1/FVC ratio, percentage predicted values of DLCO, TLC, FEV1, and FVC) for the ten stratified groups.
The error bars indicate the standard errors of mean. The numbers within parenthesis in the horizontal axis represent the number of cluster-specific cases used in the mean, standard error computation. The post-ANOVA pairwise t-test for the indicated five variables is shown as the staircase diagram with green fill for significant differences after Bonferroni correction. At least one variable is statistically significant across the clusters except for between groups (1, 2) and (5, 8).
Figure 7.
The correspondence of fibrotic and obstructive clusters with established indices and disease classification.
The Gender, Age and Physiology (GAP) based one-year mortality predictions for clusters 1, 2 and 3 in Figure 3 (A). The distribution of the old GOLD category (B) and new GOLD category (C) distribution across the obstructive clusters: 6, 7, 8, 9 and 10. The mean distribution of BODE indices across the obstructive clusters (D) and, the mean score distribution of SGRQ patient questionnaire scores of patients across all the clusters (E). The number of samples available in each cluster is noted in the horizontal axis. The error bars indicate the standard error of mean.