If chest imaging suggests the presence of pulmonary fibrous foci and small nodules, patients can be carefully asked whether they have been infected with tuberculosis in the past. Tuberculosis is prone to polymorphic changes such as exudation, proliferation, nodules, fibrosis, calcification, pleural thickening, etc. Despite standardized treatment, some tuberculosis patients still have residual fibrous foci and small nodules due to incomplete absorption on imaging. In the case of diffuse fibrotic changes in both lower lungs, one needs to be alert to the possibility of interstitial lung disease, and therefore needs to visit the respiratory medicine clinic for specialized questioning and professional follow-up guidance. In the case of small nodular lesions alone, the size and nature of the nodules need to be further defined. Nodules are classified as ground glass nodules, partially solid nodules and solid nodules. If they are smaller than 5 mm, they are called microscopic nodules, which are usually caused by chronic infection and do not require special treatment, but only dynamic follow-up. If the nodules are significantly enlarged, accompanied by early lung cancer changes such as pleural depression sign, short burr, lobar shape, etc., more tests such as enhanced CT of lung should be completed under the guidance of doctors to clarify the possibility of lung cancer.