Imaging characteristics of lung cancer detected by low-dose CT lung cancer screening

Objective: To analyze the imaging characteristics of lung cancer detected by LDCT (low-dose CT) lung cancer screening. Methods: Between July 1st, 2007 and June 30th, 2013, 7 141 asymptomatic enrolled participants aged 40-88 years old (male 4 710, female 2 431, median age 47), and 1 071 volunteer participants aged ≤ 39 underwent chest LDCT. The imaging characteristics were analyzed retrospectively in lung cancer pathologically proved. Three types were classified according to the imaging findings: solid lesion, part-solid lesion and non-solid lesion. Results: A total of 31 participants (32 lesions) were diagnosed as lung cancer, including 30 adenocarcinomas, 1 carcinoid and 1 small cell lung cancer. The detecting rate of the lung cancer was 0.4% (31/8 212). The solid lesion was further classified as classical solid nodule, inegular solid lesion and atypical solid nodule, and the part-solid lesion was further classified as part-solid nodule, irregular part-solid lesion and cystic part-solid nodule. Lung cancer or probably lung cancer was diagnosed in 24 cases (77.4%), and uncertainty diagnosis was made in 3 cases (9.7%). Benign or probably benign was diagnosed in 3 cases, and another 1 cases were missed at baseline screening. The false positive rate and the false negative rate was 9.7% and 3.1%, respectively. Conclusion: The imaging characteristics of lung cancer detected by LDCT are varied, which provide preliminary experience in lung cancer screening.