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Peripheral Quantitative Computed Tomography (pQCT) (BRSMpQCT)
Principal Investigators
Research Area:
Skeletal physiology
Species Studied
Scientific Name: Homo sapiens Species: Human

The objective of this study is to obtain more precise measures of bone mass and structure to be used in estimating bone strength particularly with regard to prolonged disuse, experienced by subjects participating in long duration bed rest studies.

Peripheral Quantitative Computerized Tomography or pQCT, is a relatively new bone measurement technology that provides information beyond that obtained by traditional DXA. This additional information includes area and bone mineral density of trabecular vs. cortical bone as well as estimates of bone strength (strength-strain index). pQCT scans can be obtained on peripheral sites including the tibia. Because pQCT can distinguish between cortical and trabecular bone (the latter of which loses bone preferentially with disuse), pQCT may prove to be a more sensitive measure than DXA for detecting disuse bone changes. If this is so, pQCT measurements might in the future allow for earlier acceptance or rejection of bone-related countermeasures than would be provided by DXA alone. JSC's long duration bed rest studies provide an important opportunity to validate the utility of pQCT measurements for monitoring disuse bone loss, with minimal associated time requirements or radiation exposure. In addition, pQCT provides important information regarding bone strength by measuring a strength-strain index for the scanned bone region. This information is not available with DXA.

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Tomography, X-Ray computed
Bone density

Photo Gallery
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Data Information
Data Availability
Archive is complete. Data sets are not publicly available but can be requested.
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Axial inertia
Cortical area
Cortical attenuation
Cortical content
Cortical density
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Mission/Study Information
Mission Launch/Start Date Landing/End Date Duration
Campaign 3 02/20/2005 04/14/2010 5 years, 1 month, 25 days
Campaign 5 04/30/2006 12/23/2007 1 year, 7 months
Pilot 02/05/2006 12/22/2006 320 days

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)