Few fibers in the middle lobe of the right lung are a sign of chronic inflammation of the lung. The interstitium has a fibrous meshwork formed by connective tissue fibers that spread throughout the lung and connect to the interstitium in the center of the lobules, which is not visible under normal conditions. It can thicken when the lung is fibrotic or infiltrative, and this fibrosis in the middle lobe of the right lung is mainly manifested by old changes of pulmonary tuberculosis. Imaging features of tuberculosis include exudation, proliferation, fibrosis, sclerosis and calcification, while the right middle lobe of the lung is prone to secondary infections, especially tuberculosis, which is a manifestation of a chronic disease and does not require excessive concern.