[An experimental and clinical study of zonography of the lung by means of Fuji computed radiography].

Tomography was conducted for a basic study using a model of the bronchi, pulmonary arteries and veins. When the exposure angle of a tube was changed to 5, 10, 25, and 50 degrees, the width of tomograms became about 10, 4, 2, and 1 cm. When tomograms of exposure angles of 50 degrees and 10 degrees were compared, the former showed fragmentary bronchi, pulmonary arteries and veins, and the latter showed bronchi, pulmonary arteries and veins branching up, down and laterally on one image in one unit and over a wide area. Similar results were obtained in 10 cases of normal volunteer. When 25 cases of lung cancer at the hilum were studied clinically with respect to bronchial lesions, the tomograms with an exposure angle of 10 degrees could point out more lesions than the tomograms with an exposure angle of 50 degrees. In 13 cases (40 lesions) which were compared with the findings of bronchoscopy, the accuracy was only 25% in tomograms with an exposure angle of 50 degrees, and 65% in tomograms with an exposure angle of 10 degrees. These results indicate that tomograms with an exposure angle of 10 degrees are useful for analysis of the bronchi, pulmonary arteries and veins at the hilum of the lung.