Dynamic regional lung function studies in patients with asthma and cystic fibrosis.

A technique is described for the determination of regional ventilation during normal breathing that uses xenon-133 and a scintillation camera. Seven normal adult male subjects, 4 patients with asthma and 5 young patients with cystic fibrosis were studied with this technique. In addition, routine pulmonary function tests and radiographic examinations of the chest were performed on the patients. The normal pattern of increasing ventilation per unit of lung volume from upper to lower zones was obtained in the normal subjects. Xenon-133 studies on 8 of the patients revealed regional ventilation abnormalities and air trapping of various degrees. Good correlation between the 133Xe studies and routine pulmonary function tests was generally obtained. In young patients with cystic fibrosis who had normal routine pulmonary function tests, regional lung function studies revealed abnormalities of ventilation. Although radiographic evaluation gave an estimate of the extent of pulmonary involvement, it failed to locate...