Abstract
We measured regional ventilation-perfusion ratio (V/Q) by continuous inhalation of Kr-81m and also continuous injection of Kr-81m.
The V/Q distribution can be divided four types. Type I is the normal pattern and V/Q value is the highest at apex. Type II has the highest V/Q value not at the apex but one third lower from the apex and the V/Q value gradually decreases towards the base. In type III V/Q has no gradient from the apex to the base. In type IV V/Q of the base higher than that of the apex. Most pulmonary emphysema show type I, most chronic bronchitis show type II and many interstitial pneumonia denote type IV. The ratio between the area in which the V/Q value was lower than 0.75, and the area of total lung (%0.75) correlated with PaO2 (r=-0.59 p<0.01).
Coefficiency of variation (COV) of V/Q was larger in pulmonary emphysema and in interstitial pneumonia than in normal lung and COY of V/Q was the largest in chronic bronchitis.
