Nodular high-density shadow in the lung is seen in old lung lesions, and the patient may have had previous tuberculosis, pulmonary fibrosis, bronchiectasis with infection, pneumonia, or lung tumor. If the lung nodule is changed in three states: ground glass, partially solid nodule, or solid nodule, further differentiation is needed to determine whether the change is benign, or malignant. If the nodule shadow is less than 5mm it is considered benign and a 1-year follow-up is recommended, and if it is between 6-8mm, a 3-month follow-up is recommended. If the nodular hyperintense lung shadow is larger than 8mm, it should be followed up once a month with a high-resolution CT of the chest, and if necessary, a thoracic surgeon should intervene surgically to obtain pathological tissue to further clarify whether it is a cancerous lesion.