Kiarash Emami1, Stephen J. Kadlecek1, Yi Xin1, Puttisarn Mongkolwisetwara1, Harrilla Profka1, Stephen Pickup1, Jianliang Zhu2, Masaru Ishii3, Rahim R. Rizi1
1Department of Radiology, University of Pennsylvania, Philadelphia, PA, United States; 2Department of Surgery, University of Pennsylvania, Philadelphia, PA, United States; 3Department of Otolaryngology, Johns Hopkins University, Baltimore, MD, United States
In this work, we evaluate the use of HP gas ADC measurements to assess the positive end-expiratory pressure (PEEP) dependence of alveolar recruitment in a healthy rat model. By maintaining a constant tidal volume, ADC can be decoupled from volume dependence and thus considered a measurement of average alveolar size. In general, it was found that higher ADC values correspond with large PEEP. Additionally, at any given PEEP, the end-inhale ADC value is larger than the end-exhale ADC value, supporting the theory that in low-recruitment conditions (large numbers of collapsed alveoli), active alveoli are over-inflated (yielding high ADC).