A pulmonary nodule is a soft tissue shadow with no obvious symptoms, a single well-defined border, increased density, ≤3 cm in diameter, and surrounded by air-containing lung tissue. Benign nodules include benign nodules and malignant nodules. Benign nodules include inflammatory pseudotumors, malignant tumors, and tuberculosis spheres are benign nodules, while malignant include primary lung cancer or metastatic lung cancer. Depending on the lesion and type, lung nodules have different shapes on the image. Typical lung cancers can be seen as short burr-like or solid dense nodules, and in the case of benign erose nodules, such as small satellite lesions around the nodular bulb. In the case of misshapen nodules, they may resemble popcorn-like shadows. Pulmonary nodules may become burr-like, like matte glass, which may suggest early lung cancer, and these are the imaging manifestations of pulmonary nodules.