Which of the following statements about the wash-in/wash-out method for performing xenon ventilation studies is true?

The statement regarding the wash-in/wash-out method for performing xenon ventilation studies that is true is that during the wash-in phase, the patient rebreathes a mixture of xenon and oxygen. This method is designed to assess lung ventilation by having the patient inhale a xenon-oxygen mixture, which allows for the measurement of xenon's presence in the lungs. This is crucial for evaluating pulmonary function, as xenon serves as a radioisotope that can be detected via imaging techniques.

During the wash-out phase, the xenon gas is then allowed to clear out of the lungs, and this clearance can be quantitatively evaluated. The combination of xenon with oxygen ensures that the gas is delivered effectively to the alveoli while avoiding hypoxia, making it an important aspect of conducting these studies safely and effectively.