[en] The term ''unevenness'' of the lung images has been used rather vaguely in perfusion and inhalation studies. The ''unevenness'' on lung perfusion images often indicates the presence of chronic obstructive pulmonary diseases, whereas the peripheral and central patterns on aerosol inhalation lung images are seen in chronic bronchitis and pulmonary emphysema, respectively. The modes of display to express ''unevenness'' on lung images are: 1. profile display, or one-dimensional display on any single line on the image; 2. contour and/or numerical display, or two-dimensional display; and 3. three-dimensional display. These are, however, nothing but qualitative expressions. The purpose of the present study was to numerize the ''unevenness'' on images, especially of lung perfusion and inhalation images and to see if there were any characteristic features among disease entities by making a comparison between these parameters of ''unevenness'' and the data of lung function tests

[en] Mucociliary clearance mechanisms were evaluated in 17 normal subjects visually and qualitatively by radioaerosol inhalation cinescintigraphy of the lung, and quantitatively by calculating the following indices: (a) overall or regional lung retention ratio; (b) airway deposition ratio; (c) airway retention ratio; (d) airway clearance efficiency; and (e) alveolar deposition ratio. The inhaled aerosol deposited homogeneously throughout the lungs, and mucus transport was always cephalad in direction and constant in velocity, although a temporary stasis of mucus was seen in smokers. Overall lung retention ratio was significantly smaller and airway deposition ratio was significantly larger in the smokers than in nonsmokers, but there was no difference between the groups in airway retention ratio or airway clearance efficiency. There was an inverse relationship between alveolar deposition ratio and cigarette consumption. Mucociliary clearance mechanisms were well maintained in the normal subjects, but in the smokers inhaled aerosol tended to deposit more proximally

[en] Lung function can be divided into two categories; one is respiratory and the other, non-respiratory. The former has been studied extensively in terms of lung function. Metabolism, immunological reactions, secretion, airway clearance etc. belong to non-respiratory lung function. Non-respiratory lung function, therefore, can be potentially important in the defense and maintenance of body function, but few in vivo clinical studies have been carried out as far mainly due to the lack in methodology. Usually sequential images of the lungs following radioaerosol inhalation were taken for several hours to estimate mucociliary clearance but its drawback was that the transport of radioactivity between one measurement and the next was not known and that exact positioning of the patient at each measurement was difficult. ''Radioaerosol inhalation lung cine-scintigraphy'' seems to be best suited to studying muco-ciliary transport mechanism and has overcome the drawbacks of previous sequential radioaerosol inhalation lung imaging, because it has enabled not only a visual evaluation of the actual migration of inhaled radioactivity in the lungs but also it has allowed the quantitative measurement of clearance rate in various regions of interest and the transport velocity over the trachea and the major bronchi

[en] Using radioaerosol inhalation lung cinescintigraphy, pulmonary clearance mechanisms were studied in 21 patients with obstructive airways disease. In none of them did we find homogeneous deposition of inhaled radioaerosol in the lungs, or a steady, constant, axial, and cephalad transport of radioactivity in the major airways. Of the 21 patients, 14 showed temporary but frequent stopping and starting of radioactivity in the airways in the course of lung clearance; in ten there was reversal of flow; in five migration of radioactivity from one bronchus into the opposite, bypassing the trachea and often followed by shuttling between right and left bronchi; and in four there was spiral or zigzag transport of radioactivity. The alveolar deposition ratio was also significantly smaller in these patients