Fibrous striae in the middle lobe of the lung are abnormal density shadows in the lung found under CT chest examination, which appear as slightly dense shadows distributed along the lung texture with a fibrous stripe-like structure. They are usually old lesions, which may be scar-like tissues from previous pneumonia or tuberculosis that have been treated or healed by autoimmunity, and usually do not cause discomfort. If the fibrous streak shadow is caused by tuberculosis, accompanied by fever, coughing blood, chest tightness, shortness of breath and other symptoms, it is recommended to promptly go to the hospital to review the chest CT, sputum for tuberculosis bacteria, etc., to see if the tuberculosis is recurring.