[Planimetric determination of lung volume and its significance in the radiological diagnosis of pulmonary emphysema].

The volume of the lungs of 102 patients with emphysema and of 33 normal individuals, aged between 30 and 79 years, was determined with the use of a digital planimeter from routine chest x-rays in two planes. Contrary to the values obtained by a helium dilution method, the volumes, as determined by planimetry, did not show a linear relationship with age, but showed an increase after the age of 60. This agrees with the results of total body plethysmography, carried out by Amrein et al. The planimetric method of Harris, Pratt and Kilburn is a simple and rapid method for demonstrating, even in the presence of regional ventilatory abnormalities, total volume with sufficient accuracy, which complements and quantifies the radiological diagnosis of emphysema.