Adaptation of lung mechanics during constrained breathing using 3D MRI spirometry

Motivation: New mechanical biomarkers to characterize lung pathophysiology using 3D MR spirometry.Goal(s): To investigate the dynamics of lung elongations along the three anatomical directions when the lungs are constrained during breathing.Approach: 3D MR spirometry was performed in 25 healthy volunteers spontaneously breathing and in a healthy volunteer for three types of breathing (spontaneous, thoracic, diaphragmatic). Results: The main respiratory driving force is produced by the diaphragm as it is assessed here with a dominant superior-inferior normal strain in basal pulmonary regions. In spontaneous breathing, it is supplemented mainly by the anterior-posterior normal strain in the apical regions. Impact: Dynamic normal strains are original mechanical biomarkers that provide new insight on the regional anisotropic behaviour of the lungs.