Detection of Obstructive Pulmonary Disease

A double-blind evaluation of the chest radiographs and ventilation-perfusion scans of 160 patients was performed to assess their relative sensitivity in detecting obstructive airway disease. In 76 the initial scan diagnosis was obstructive pulmonary disease; 35 of these showed no radiographic evidence of COPD. The abnormalities in these 35 were significantly milder than in the 41 others. Perfusion scans were normal in 7 patients with mild disease and normal radiographs. Regional ventilation studies are helpful in evaluating cases of mild to moderate airway obstruction which would be misdiagnosed by radiographs or perfusion scans alone.