Low-dose spiral CT is a type of CT with a lower radiation dose than ordinary spiral CT. Low-dose spiral CT has little radiation damage and is commonly used for early lung cancer screening. For example, long-term smoking history, family history of lung cancer, long-term dust exposure, and history of chronic lung disease may be considered for initial screening with low-dose spiral CT. Low-dose spiral CT has a much smaller radiation dose than ordinary spiral CT and causes less damage to the body. Low-dose spiral CT is not recommended for examinations of the abdomen, cranium and brain, as it is prone to cause missed diagnosis. If the diagnosis of ordinary CT is not clear, enhanced CT is also performed to clarify the disease. It is recommended to consult the doctor in time, and the doctor will choose the appropriate examination method according to the condition.