Late Breaking Abstract - CT-based diaphragm analysis to evaluate the diaphragm configuration with increasing COPD severity

Introduction The relation between the degree of diaphragm flattening and lung function impairment in COPD remains largely unknown. We aim to develop a CT-based diaphragm analysis tool to investigate the association between diaphragm configuration and pulmonary function in COPD. Methods We developed a CT-based diaphragm analysis tool based on: 1) identification of the pulmonary lobes using an AI-based lung quantification platform (LungQ, Thirona, Nijmegen, The Netherlands), 2) extraction of a 3D-shape map of the lung-diaphragm intersection (Figure 1A), and 3) calculation of a diaphragm index (ratio of diaphragm surface area/projected surface area). Inspiratory CT scans from the first phase of the COPDGene study (n=9567) were used to evaluate the relation between the automatically extracted diaphragm index and FEV1 %-predicted, GOLD stages, and CT quantified emphysema (LAA<-950) (Figure 1). Results We found a significant association between the diaphragm index and emphysema (Figure 1C), FEV1 %- predicted (Figure 1D), and the COPD GOLD stages (Figure 1B). Conclusions With an in-house developed, automatic CT-based diaphragm analysis tool, we showed significant differences in diaphragm configuration relative to pulmonary function in COPD.