Shear-wave Elastography Compared to Respiratory Function Testing

The purpose of this study is to evaluate the relationship between transdiaphragmatic pressure (Pdi) and diaphragm shear-wave elastography (SWE) during state-of-the-art respiratory muscle testing including volitional efforts (e.g., maximal inspiratory pressure, maximal expiratory pressure, Valsalva maneuver), as well as maximal phrenic nerve stimulation.