According to the data from the National Tumor Registry, the number of new lung cancer cases in China reached 605,900 in 2010, ranking first in malignant tumors. Low-dose spiral CT (LDCT) is 4-10 times more sensitive than conventional chest radiography in detecting early lung cancer, and can detect about 85% of stage I peripheral lung cancer (the expected survival rate of 10 years after surgery for stage I peripheral lung cancer is 92%). The U.S. National Lung Cancer Screening Trial demonstrated that low-dose spiral CT screening can reduce lung cancer mortality by 20%, making it the most effective lung cancer screening tool available. Low-dose spiral CT has low radiation exposure and is not associated with health effects when received once a year.