Inventi Impact: Radiology

Inventi:hrd/22449/17

Respiratory Changes in the Superior Vena Cava Area on Inspiratory and Expiratory Chest CT:\nComparison between Patients with COPD and with Bronchial Asthma

Purpose: In patients with obstructive lung diseases, alteration of intrathoracic pressure\nis closely related to hyperinflation and leads to hemodynamic impairments.\nBoth intrathoracic pressure and hemodynamics are affected by the respiratory phase.\nIn fact, a previous study showed that respiratory phasic variations in the superior\nvena cava (SVC) area significantly correlated with the extent of emphysema. Chronic\nobstructive pulmonary disease (COPD) and bronchial asthma manifest different pathophysiological\nchanges in hyperinflation and hemodynamics. The current study\nwas conducted to evaluate differences in respiratory variations in the cross-sectional\narea of the SVC between patients with COPD and with asthma. Materials and Methods:\nWe measured the SVC area and calculated the ratio of the SVC area on inspiratory\nand expiratory scans (i/e-SVC ratio) in 66 patients with COPD and 16 patients\nwith asthma. The correlations of the i/e-SVC ratios with airflow limitation, pulmonary\nsmall vessels less than 5 mm2 (%cross-sectional area [%CSA] < 5), and respiratory\nchanges in lung volume (i/e-LV) obtained by inspiratory and expiratory computed\ntomography (CT) images were evaluated. Results: There was no significant\ndifference in i/e-SVC ratio between COPD and asthma groups. In COPD patients,\nthe i/e-SVC ratio significantly correlated with the %CSA < 5 (ρ = âË?â??0.433, P = 0.003),\ni/e-LV ratio (ρ = âË?â??0.371, P = 0.011), and percent of predicted forced expiratory volume\nin 1 second (FEV1% predicted) (ρ = âË?â??0.474, P = 0.001), whereas in asthma patients,\nthere were no significant correlations between the i/e-SVC ratio and those\nfunctional parameters. Conclusion: There would be differences in the relationship\nbetween intrathoracic pressure and cardiopulmonary hemodynamics between COPD