Fig. 9
From: Ultrasound and non-ultrasound imaging techniques in the assessment of diaphragmatic dysfunction
Reproduced with permission from The American Thoracic Society: Cassart et al. Am J Respir Crit Care Med 1997;156:504–508
Three-dimensional reconstructed images of the diaphragm at functional residual capacity in (a) a control subject and (b) a patient with COPD. The numerical units represent centimeters. Compared to the control subject, the patient with COPD has a markedly smaller muscle surface area.