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Evaluation of Muscle Size Measurement with Ultrasound and Magnetic Resonance Imaging – Pilot Study (EORS_Ultrasound)
Principal Investigator
Research Area:
Muscle physiology
Species Studied
Scientific Name: Homo sapiens Species: Human

Crewmembers continue to experience muscle atrophy after space flight, particularly from long-duration missions on the International Space Station (ISS), which results in higher risk for injury upon their return to Earth. More robust exercise equipment is arriving on the ISS and new exercise prescriptions are planned to counteract the muscle losses. With these new exercise countermeasures; however, there currently are no methods to monitor muscle status in flight to assist in determining the efficacy of these countermeasures. Given that medical imaging with ultrasound is available on the ISS, it is feasible that ultrasound scanning could be performed before, during, and after space flight to assess muscle size changes. This ground-based pilot study evaluated and validated a technique of using ultrasound to measure leg muscle cross sectional area (CSA) and volume. These ultrasound measures were also compared with a magnetic resonance image (MRI) of the leg to determine the accuracy and repeatability of the ultrasound muscle measurements. This pilot study is part of the larger Integrated Resistive and Aerobic Training Study (SPRINT) conducted on the ISS. Ultrasound will ultimately be used to assess the effectiveness of the SPRINT exercise prescription on ISS crewmembers using the Advanced Resistive Exercise Device (ARED) and the second generation treadmill (T2) during their missions. This ultrasound technique could also be applicable for evaluating future exercise countermeasures both on ISS and Constellation missions.

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Magnetic resonance imaging (MRI)
Cross-sectional area (CSA)

Photo Gallery
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Data Information
Data Availability
Archive is complete. Data sets are not publicly available but can be requested.
Data Sets+ Request data

Lateral gastrocnemius - CSA
Lateral gastrocnemius - volume
Medial gastrocnemius - CSA
Medial gastrocnemius - volume
Rectus femoris - CSA
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Mission/Study Information
Mission Launch/Start Date Landing/End Date Duration
ECP 02/01/2005 12/31/2010 In Progress

Additional Information
Managing NASA Center
Johnson Space Center (JSC)
Responsible NASA Representative
Johnson Space Center LSDA Office
Project Manager: Jessica Keune
Institutional Support
National Aeronautics and Space Administration (NASA)