[Assessment of regional ventilation using the inhalation of a radioactive and an aerosol of a 113mIn-labelled colloid solution].

Two methods of assessing regional ventilation distribution-dynamic scintigraphy with 133Xe-labelled gas inhalation, and pulmonary scanning following the inhalation of 113mIn-labelled colloid aerosol-were subjected to critical review. A total of 10 normal controls, 5 cardiac patients and 12 patients with pulmonary diseases were examined using both techniques. The subjective imaged of the lungs converged only in 24% of the cases. A considerable discrepancy in the results of the two investigation procedures was noted in 76%, primarily due to the sedimentation of inhaled colloid along the air passages. It is suggested that radio-aerosol scanning cannot visualize actual distribution of ventilation throughout the lungs; however, the method can be useful in the diagnosis of minor bronchial patency disorders before dynamic investigation using 133Xe can detect any changes, or where gamma-counter and analyzer facility is not available. To provide an accurate assessment of regional ventilation, the gas inhalation method should be combined with the dynamic analysis using a gamma-counter and analyzer facility, and perhaps a computer.