Quantifying ventilation by X-ray velocimetry in healthy adults.

Rationale: X-ray velocimetry (XV) has been utilized in preclinical models to assess lung motion and regional ventilation, though no studies have compared XV-derived physiologic parameters to measures derived through conventional means.

Objectives: To assess agreement between XV-analysis of fluoroscopic lung images and pitot tube flowmeter measures of ventilation.

Methods: XV- and pitot tube-derived ventilatory parameters were compared during tidal breathing and with bilevel-assisted breathing.