Ultrasonic 360 degrees cross section scanning methodology for monitoring bone and muscle areas during space flight

SA has identified the changes of bone and muscle during long duration spaceflight as a significant risk, prompting interest in the development of monitoring technologies. Ultrasound techniques have been used for muscle Cross-Sectional Area (CSA) measurement, but have historically relied on trained experts performing the scanning and did not address hone area measurement. A methodology using 360 degrees ultrasonic scanning has been developed to address the need for non-invasive monitoring of muscle and bone CSA in limbs. The current work was based on a previous study, which used simulations to validate the 360 degrees ultrasonic scanning methodology for effective muscle CSA measurement. The 360 degrees ultrasonic scanning, methodology was used to perform limb surrogate scans for determining the cross-sectional area values for bone and muscle. B-mode image data was collected using a SonoSite 180P ultrasound unit and the data was processed using custom software. Three sets of 360 degrees scanning data were collected with 96 rotation stations each. The mean percent error between reference values and cross-sectional areas determined from reflection points for the total limb, muscle, and bone was 0.885%, -2.371%, and +5.627%, respectively. When data for only 48 stations was processed, the methodology produced higher mean percent errors for the total limb, muscle, and bone of 2.291%, -4.421%, and +7.042%, respectively. The mean percent errors for muscle are within the 5% target established based on previous B-mode techniques, and the methodology was able provide approximations for the hone area where previous techniques did not.