Incidental Finding Prevalences in 3-Tesla Brain and Spine MRI of Military Pilot Applicants

INTRODUCTION: Incidental findings in brain and spine MRI are common. In aerospace medicine, pilot selection may be affected by improved sensitivity of modern MRI devices. We investigated the occurrence of medically unfit rates caused by incidental findings in military pilot applicants using a 3-Tesla scanner as compared to the outcomes of a lower field strength 1-Tesla device based on similar screening protocols.METHODS: A total of 3315 military pilot applicants were assessed by a standardized German Air Force Imaging Screening Protocol and retrospectively subdivided into two cohorts, one of which was assessed by 1-Tesla MRI (2012-2015; N 1782), while in the second cohort (2016-2019; N 1808), a 3-Tesla MRI was used. Cohorts were statistically analyzed relating to three entities of incidental findings: 1) intervertebral disc displacements, 2) intracerebral vessel malformations, and 3) other abnormal findings in the brain.RESULTS: Pooled prevalences of incidental findings in medically unfit applicants significantly increased by use of 3-Tesla MRI as compared to lower resolution 1-Tesla MRI. Regarding the spine, prevalences more than doubled (1.46 vs. 4.99%; P < 0.05) for intervertebral disc displacements. Similarly, prevalences of cerebral vessel malformations as well as other abnormal CNS incidental findings considerably increased by use of 3-Tesla MRI (0.28 vs. 1.67%; P < 0.05, and 5.12 vs. 9.80%; P < 0.05). Effect sizes and correlations were substantial in all conditions analyzed (Cohens d > 0.8; Pearsons r > 0.75).CONCLUSIONS: Our data suggest a strong dependency of incidental cerebrospinal findings on image resolution and sensitivity of MRI devices used for screening, which is enhanced by refined imaging protocols and followed by increased medical unfit rates in prospective aviators. Adjusted strategies in the assessment of such lesions are needed to redefine their natural history and physiological impact, and to optimize screening protocols for future pilot selection.Snksen S-E, Khn SR, Nobl H-J, Knopf H, Ehling J, Jakobs FM, Frischmuth J, Weber F. Incidental finding prevalences in 3-Tesla brain and spine MRI of military pilot applicants. Aerosp Med Hum Perform. 2021; 92(3):146152.

Improving the pilot selection process by using eye-tracking tools

This paper improves the understanding of the use of eye-tracking tools in the pilot selection process. Research of eye movement and attention distribution of candidate pilots may provide the capability for visual behavior prediction in more demanding flight training phases. The research included psychological testing, flight screening of subjects and their achievements in a flight simulator in combination with an eye-tracking device. Participants were divided into three categories: high performance, average performance, and low performance and separately regarded through psychological testing results and flight screening results. An eye-tracking device tracked visual behavior of subjects through the scope and speed of visual perception. The number of fixations and revisits recorded during the simulated visual flight conditions measured the difference in visual response between subjects. Comparison of results showed a positive correlation with psychological test results. Correlation with flight screening selection was not confirmed. We used the new network-based approach with three target importance measures to overcome the shortcomings of traditional eye movement metrics. The results of the adopted network approach presented in the form of graphs and analysis of normalized importance measures showed that it was possible to extract specific saccade strategy for each participant. Discovered differences between them positively detected week ones. In this way, Eye-tracking tools can potentially improve the pilot selection process and complement other tests and assessment methods.

Improved Pilot Selection for Channel Estimation of Polar Codes in Wireless 5G

Fading channels learning about polar codes is great prominence. Knowledge of polar codes is very important while they are applied to the wireless communication systems. In fading Channels the communication through channel estimation which is an essential step for communication. The structure is constructed by a set of information bits for both systematic polar code and non-systematic polar code and the information set recognized frozen bits. In fading channels uneven pilot selection scheme and even pilot selection scheme are two pilot selection schemes are considered for polar codes. There is an improvement in decoding performance of polar codes using these selection schemes. In this choosing of coded symbols treated as pilots is a replacement of insertion of pilots. Polar codes have poor performance in fixed domain. So the EPS selection scheme can be active for tracing or channel estimation. The structure of polar code encoding is acapable structure and pilot selection is grave since whole selections cannot use the existing structure again. By conjoining the above advantages, pilot signals are selected without any addition from outside and insertion of pilot symbols impartial to estimation of the channel. Leveraging this, the DM-BS scheme is applyto multiple input multiple output (MIMO) system in frequency selective fading channel.