Follow-Up of Blebs and Bullae in Pilots 40 Years and Older Using CT

BACKGROUND: Preventive treatment for incidentally detected blebs or bullae is required for fast jet pilots, but their aeromedical risk is not clearly proven.METHODS: This is a retrospective study and includes 46 pilots 40 yr and older with incidentally detected emphysema-like changes (ELCs) comprising blebs or bullae in low-dose chest CT (LDCT) during health screening. Two radiologists retrospectively reviewed imaging features. Statistical analysis was done using independent t-tests and bivariate analysis.RESULTS: Among 46 pilots, 39 pilots flew fast jet aircraft and 7 pilots flew nonfast jet aircraft. The mean follow-up period was 1531 d and the LDCT follow-up interval mean period was 424.4 d. There was no evidence of rupture in incidentally detected ELCs during the follow-up period. The mean size of the ELCs was 19.15 mm. There were five cases showing changes in size. There was a statistically significant correlation between the size of ELCs and height. There were no statistically significant differences in the size or number of ELCs relating to smoking status or aircraft type, and there were no statistically significant correlations between the size or number of ELCs and multiple factors, including smoking quantity, flight time, age, BMI, and weight.CONCLUSION: This study demonstrates the aeromedical safety of incidentally detected ELCs in pilots 40 yr and older without underlying lung disease. The results indicate no need for recommending preventive treatment for ELCs in pilots 40 yr and older, even those flying fast jet aircraft, as a requisite to continue their flight duties. KEYWORDS: bleb, bulla, pilot, CT.Bang S, Yang S, Cho SW, Kim DH, Kang H.