Chest radiographs of patients with emphysema may show increased translucency at the lesions compared to normal, because emphysema is mainly due to chronic inflammation of the lungs caused by various factors, resulting in a decrease in the elastic retraction force of the alveoli, an increase in the amount of gas in the lungs, an excessive amount of residual gas that cannot be discharged, and a decrease in the density of gas relative to the lungs. Especially in the lesions of emphysema, patients who have a combination of infection, such as bacterial infection may have an increase in inflammatory secretions at the lesions, which may appear as patches of dense shadows of varying size or uniform distribution at the lesions of inflammation. If cardiac insufficiency is present, the pulmonary artery may appear protruding and thickened when pulmonary heart disease is triggered, and there are shadows of hypertrophy of the right side of the heart.