Fig. 1.

Lung mechanical properties measured with imaging. Effective lung stiffness maps measured in a porcine model at four levels of opening airway pressure with an MRI elastography method. Stiffness is calculated by detecting shear waves produced by a noninvasive mechanical driver placed on the chest wall. With synchronized motion-sensitizing magnetic field gradients, small displacements of a lung element (<10 μm) are detectable as phase changes of the MR signal. [Adapted with permission from Mariappan et al. (48)].