Feasibility Study: QCT Modality for Risk Surveillance of Bone - Effects of In-flight Countermeasures on Sub-regions of the Hip Bone (Hip QCT) - 07.14.16
Hip QCT aims to use quantitative computed tomography (QCT) as a surveillance technology to monitor changes in hip bone structure in response to in-flight bone countermeasures. The regions of bone being measured are determinants of fracture risk and will help define the response of hip bone structure to spaceflight, to countermeasures and after return to earth. Science Results for Everyone
Information Pending Experiment Details
Jean D. Sibonga, Ph.D., Johnson Space Center, Houston, TX, United States
Joyce H. Keyak, Ph. D., University of California at Irvine, Irvine, CA, United States
Elisabeth R. Spector, Wyle Laboratories, Houston, TX, United States
Scott A. Smith, Wyle Laboratories, Houston, TX, United States
Harlan J. Evans, Ph.D., Wyle Laboratories, Houston, TX, United States
Thomas F. Lang, Ph.D., University of California, San Francisco, CA, United States
NASA Johnson Space Center, Human Research Program, Houston, TX, United States
Sponsoring Space Agency
National Aeronautics and Space Administration (NASA)
Human Exploration and Operations Mission Directorate (HEOMD)
Earth Benefits, Space Exploration
ISS Expedition Duration
March 2013 - March 2014; March 2015 - March 2016
This study shares QCT data obtained from on-going ISS investigations: Bisphosphonates as a Countermeasure to Space Flight Induced Bone Loss, and/or Sprint integrated Resistance and Aerobic Training Study.
- It needs to be understood if long duration ISS crew members are more susceptible to developing osteoporosis at a younger age because of bone changes that occur during missions in space. Recent research, using an imaging device for the hip called QCT, has described changes in the structure of the hip during spaceflight. This study describes how those changes in bone structure affect the strength of the hip bone and how losses in hip strength might be prevented or recovered.
- The study uses the QCT instrument at a local hospital to measure hip structure and describe how different types of bone loss countermeasures being tested in space (a drug vs. exercise) change the structure of the hip differently.
- A special software analysis tool computes the strength of the hip from the QCT measurements. This results tell if, and how, tested countermeasures affect the hip bone strength in space.
The information collected from this surveillance study helps a clinical advisory panel assess if there is a requirement to prevent early onset osteoporosis in long-duration astronauts, the type of preventative countermeasure, and the optimal timing (preflight, in-flight or postflight) for that countermeasure. The QCT data of hip bone structure, and the estimation of hip bone strength by Finite Element Modeling (FEM), provides additional characterization on how hip adapts to spaceflight, which will improve the ability to forecast hip fractures, during a mission, by modeling efforts.
This study of younger-aged crew members adds to a growing population data set of hip bone strengths, estimated by Finite Element Modeling (FEM). FEM-based cut-points for fracture risk are being investigated as an index to assess the efficacy of osteoporosis therapies -- as an alternative to monitoring fracture outcome. This approach may be valuable for the rare, complex subject with bone loss.
Operational Requirements and Protocols
Decadal Survey Recommendations
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Ground Based Results Publications
Lang TF, LeBlanc AD, Evans HJ, Lu Y. Adaptation of the Proximal Femur to Skeletal Reloading After Long-Duration Spaceflight. Journal of Bone and Mineral Research. 2006 May 29; 21(8): 1224-1230. DOI: 10.1359/JBMR.060509.
Keyak JH, Koyama AK, LeBlanc AD, Lu Y, Lang TF. Reduction in proximal femoral strength due to long-duration spaceflight. Bone. 2009 March; 44(3): 449-453. DOI: 10.1016/j.bone.2008.11.014. PMID: 19100348.
Lang TF, LeBlanc AD, Evans HJ, Lu Y, Genant HK, Yu A. Cortical and Trabecular Bone Mineral Loss from the Spine and Hip in Long-duration Spaceflight. Journal of Bone and Mineral Research. 2004; 19(6): 1006-1012. DOI: 10.1359/JBMR.040307.
Representative image of a clinical Quantitative Computed Tomography [QCT] instrument (left side) with its capability of detecting the transmission of x-rays in hip bone over three dimensions. Representative QCT scan of hip (right side) with mineral-dense cortical bone in red and the trabecular "spongy" bone compartment in blue. Image courtesy of HRP
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Representative analysis of hip QCT images by Finite Element Modeling. This mathematical model of the 3-D hip structure can be used to calculate the force required to fracture the hip, based upon the 3-D geometry and mechanical properties computed from each astronaut’s QCT bone density. These plots illustrate the von Mises stress distributions in two proximal femora of males representing typical control subjects (left) and fracture subjects (right). Image courtesy of HRP.
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