Uneven ventilation within and between regions of the normal measured with nitrogen-13.
D006801:Humans; D008297:Male; D009055:Mouth; D009584:Nitrogen; D011868:Radioisotopes; D012119:Respiration; D013147:Spirometry; D013909:Thorax; D013997:Time Factors
D011868:Radioisotopes; D009584:Nitrogen