Prevalence of Incidental Findings in Computed Tomographic Screening of the Chest: a Systematic Review

Objective: To perform a systematic review on the prevalence of incidental findings in computed tomographic (CT) screening studies of the chest.

Methods: We selected CT screening studies of the chest (screening for coronary artery disease [CAD] [coronary calcium and CT coronary angiography] and lung cancer screening). Screening protocols, descriptions of baseline characteristics, range of incidental findings, and recommendations for follow-up were abstracted.

Results: Eleven chest CT screening studies were identified. The proportion of people with at least 1 imaging abnormality requiring follow-up varied widely between studies (3%-41.5%). This was largely due to considerable variation in follow-up recommendations for incidental findings across studies. Analyzed by subgroup, 7.7% (confidence interval, 7.0%-8.3%) of 6421 participants in CAD screening had further investigations compared with 14.2% (confidence interval, 13.2%-15.2%) of 4531 participants in lung cancer screening.

Conclusions: In this review, 7.7% and 14.2% of patients undergoing either CAD or lung cancer screening with CT were found to have clinically significant incidental findings requiring additional investigations.