Space Radiology: Emerging Nonsonographic Medical Imaging Techniques and the Potential Applications for Human Spaceflight.

Space medicine is a multidisciplinary field that requires the integration of medical imaging techniques and expertise in diagnosing and treating a wide range of acute and chronic conditions to maintain astronaut health. Medical imaging within this domain has been viewed historically through the lens of inflight point-of-care ultrasound and predominantly research uses of cross-sectional imaging before and after flight. However, space radiology, a subfield defined here as the applications of imaging before, during, and after spaceflight, will grow to necessitate the involvement of more advanced imaging techniques and subspecialist expertise as missions increase in length and complexity. While the performance of imaging in spaceflight is limited by equipment mass and volume, power supply, radiation exposure, communication delays, and personnel training, recent developments in nonsonographic modalities have opened the door to their potential for in-mission use. Additionally, improved exam protocols and scanner technology in combination with artificial intelligence algorithms have greatly advanced the utility of possible pre- and postflight studies. This article reviews the past and present of space radiology and discusses possible use cases, knowledge gaps, and future research directions for radiography, fluoroscopy, computed tomography, and magnetic resonance imaging within space medicine, including both the performance of new exam types for new indications and the increased extraction of information from exams already routinely obtained. Through thoughtfully augmenting the use of these tools, medical mission risk may be reduced substantially through preflight screening, inflight diagnosis and management, and inflight and postflight surveillance.