Incidental Findings on MRI Brain Imaging in Pilots from the Canadian White Matter Hyperintensity Study

BACKGROUND: Incidental neuroanatomical findings are commonly identified during brain MRI completed clinically, for research, or for other purposes, including aircrew screening. Such findings range from benign to pathological and some may be disqualifying for flight duties. We present a series of cases with incidental neuroanatomical findings identified in Royal Canadian Armed Forces (RCAF) aircrew during the Canadian White Matter Hyperintensity research study, and the subsequent aeromedical evaluation undertaken to manage them. Our study group performed 48 brain MRI scans on 42 RCAF pilots and 6 aviation physiology technicians and parajumpers. Participants were men ages 25-70 with a mean age of 39. CASE SERIES: Incidental neuroanatomical findings were detected in four pilots, with six distinct findings (four vascular abnormalities, one arachnoid cyst, and one nonspecific nodule). All cases were asymptomatic. After evaluation of the findings of each case by a medical consortium, including an aeromedical neurologist, all pilots were cleared for ongoing duties with no restrictions. DISCUSSION: The rate and nature of incidental findings in RCAF members in the White Matter Hyperintensity Study is consistent with that found in both the general population and in other military pilot populations. There is no international standard for screening or management of incidental findings; therefore, we recommend an approach that involves a case-by-case evaluation of the findings by a multidisciplinary medical team, with careful identification and consideration for high-risk features.