Regional lung function in patients with obstructive lung diseases.

Regional lung function was measured, using radioactive xenon-133, in a group of normal subjects and in three carefully defined groups of patients with obstructive lung disease. When compared with the normal subjects, patients in the emphysematous group showed a relative reduction of ventilation and perfusion to the upper zones, while patients having chronic bronchitis without cardiac or respiratory failure showed a predominantly lower zone defect. In the group of patients with chronic bronchitis with cardiac and respiratory failure no consistent pattern was found.