There can be burr-like changes around the lung nodules on CT examination of the lungs. The burr sign is mostly seen in patients with malignant tumors, but it can also be seen in some benign nodules. For malignant lung tumors, the burr sign mostly appears as thick and short burr-like changes, mostly caused by the proliferation, thickening and pulling of blood vessels around the tumor, while benign nodules, such as inflammatory pseudotumors, tuberculosis spheres, and certain benign tumor patients, are mostly caused by the proliferation of fibrous tissue, so their burrs are mostly elongated. The nodules should be observed for lobar, vacuolar, pleural traction and vascular collection signs. In addition, the burr sign of the nodule is an imaging sign, and the determination of the nature of the nodule still depends on the clinical symptoms of the patient and the pathological diagnosis after puncture or surgical excision of the nodule.