Fig. 7.

Example images reconstructed from projection data acquired over 30 seconds of scanning during in vivo mechanical ventilation of a pig, using (a) conventional mechanical ventilation at 0.4 Hz (24 min⁻¹), (b) high-frequency oscillatory ventilation at 5 Hz (300 min⁻¹), (c) high-frequency oscillatory ventilation at 20 Hz (1200 min⁻¹), and (d) multi-frequency oscillatory ventilation using a broadband waveform containing energy at 5, 10, 15, and 20 Hz. Both ventilatory and cardiac frequencies were reconstructed from the same projection data. Transient profiles from each image are presented through a single slice from the transverse plane over 1 to 6 seconds, showing resolved motion across subject phase bins equally spaced throughout the periodic motion cycles.