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).