Stable small animal ventilation for dynamic lung imaging to support computational fluid dynamics models.

Area of Science:

• Physiology
• Medical Imaging
• Engineering

Background:

• Dynamic lung imaging for computational fluid dynamics requires stable ventilatory mechanics.
• Long imaging times in small animals can lead to lung derecruitment and altered mechanics.
• Changes in lung mechanics manifest as pressure and volume waveform drift during experiments.

Purpose of the Study:

• To demonstrate highly repeatable mechanical ventilation in anesthetized rats for extended dynamic lung CT imaging.
• To describe modifications to a commercial ventilator to ensure consistent lung mechanics.
• To present methods for monitoring and controlling ventilatory parameters during long-term imaging.

Main Methods:

• Modified a commercial mechanical ventilator for long-duration use in rats.
• Implemented periodic deep breaths (sighs) to maintain lung recruitment.
• Continuously monitored breath-to-breath pressure and volume waveforms and peak inspiratory pressure (PIP).

Main Results:

• Achieved highly repeatable mechanical ventilation over extended imaging durations.
• Periodic sighs effectively prevented lung derecruitment and maintained consistent lung mechanics.
• Continuous monitoring provided diagnostics for detecting and managing changes in breathing mechanics.

Conclusions:

• Modified mechanical ventilation with periodic sighs ensures stable lung mechanics for dynamic imaging.
• Continuous monitoring is essential for diagnosing and controlling ventilatory changes during long experiments.
• This approach enhances the reliability of pulmonary computational fluid dynamics models derived from dynamic lung imaging.