Measurement of the Exponential Decay of Alveolar Partial Pressure of Oxygen Using Hyperpolarized 3He MRI in Animals and Human Subjects

Katarzyna Cieslar¹, Elise Bannier¹, Philippe Reix², Sophie Gaillard¹, Emmanuelle Canet-Soulas¹, Yannick Crmillieux¹

Using 3He-MRI it is possible to locally measure the alveolar partial pressure of oxygen (pO2) and its temporal evolution during apnea. The aim of this work was to demonstrate the feasibility of using a physiologically appropriate exponential model of pO2 decay in animals and humans. The exponential model was successfully applied to measure initial pO2 and oxygen depletion time constant r in mice, rats, rabbits and humans. Numerical simulations were performed to assess when the use of the nonlinear pO2 decay model is inevitable to obtain satisfying accuracy of the measured parameters.