Through the Looking Glass and What Was Found There: Imaging Biomarkers of Chronic Obstructive Pulmonary Disease
American Journal of Respiratory and Critical Care Medicine
URL with Digital Object Identifier
Through the Looking-Glass and What Alice Found There (1) describes adventures in a new and alternative world that Alice discovered after stepping through to the other side of a mirror. Importantly, one of this enduring novel’s underlying themes is the presence of inverse reflections and the notion that in the looking-glass world, one’s basic assumptions can be reversed. In a similar manner, in this issue of the Journal, Bodduluri and colleagues (pp. 1404–1410) present a new “through the looking-glass” way of evaluating normal lung regions that, surprisingly, reveals gas trapping not detected using the typical X-ray computed tomography (CT) density thresholds (2). Like the looking-glass adventures, this approach is intuitive and stimulating, and these findings are both clinically relevant and revelatory. Notably, their findings add to the substantial body of work that stems from the Genetic Epidemiology of COPD (COPDGene) study (3), which has improved our understanding of chronic obstructive pulmonary disease (COPD) and provided novel biomarkers of COPD using high-resolution CT. Although COPDGene was designed to identify genetic factors associated with COPD, reports of CT imaging biomarkers as objective measures of disease have dominated, in that nearly half of all COPDGene publications describe CT findings (using PubMed “COPDGene” and “COPDGene and CT”).