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Brain MR imaging scans of National Aeronautics and Space Administration astronauts were retrospectively analyzed to quantify pre- to postflight changes in brain structure. Local structural changes were assessed using the Jacobian determinant. Structural changes were compared with clinical findings and cognitive and motor function. Long-duration spaceflights aboard the International Space Station, but not short-duration Space Shuttle flights, resulted in a significant increase in the percentage of total ventricular volume change (10.7% versus 0%). The percentage of total ventricular volume change was significantly associated with mission duration but negatively associated with age. Pre- to postflight structural changes of the left caudate correlated significantly with poor postural control, and the right primary motor area/midcingulate correlated significantly with a complex motor task completion time. These findings suggest that brain structural changes are associated with changes in cognitive and motor test scores and with the development of spaceflight-associated neuro-optic syndrome.

This study assesses the accuracy of combined velocity-selective arterial spin-labeling and traditional pulsed arterial spin-labeling CBF measurements in pediatric Moyamoya disease, with comparison with blood flow patterns on conventional angiography. Twenty-two neurologically stable pediatric patients with Moyamoya disease and 5 asymptomatic siblings without frank Moyamoya disease were imaged with velocity-selective arterial spin-labeling, pulsed arterial spin-labeling, and DSA (patients). Qualitatively, velocity-selective arterial spin-labeling perfusion maps reflect the DSA parenchymal phase, regardless of postinjection timing. Conversely, pulsed arterial spin-labeling maps reflect the DSA appearance at postinjection times closer to pulsed arterial spin-labeling postlabeling delay, regardless of vascular phase. ASPECTS comparison showed excellent agreement between arterial spin-labeling and DSA, suggesting velocity-selective arterial spin-labeling and pulsed arterial spin-labeling capture key perfusion and transit delay information, respectively. Velocity-selective arterial spin-labeling offers a powerful approach to image perfusion in pediatric Moyamoya disease due to transit delay insensitivity.