An Investigation of Local Microarchitecture Topology Changes in Long-Duration Spaceflight

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dc.contributor.advisorBoyd, Steven
dc.contributor.authorMielczarek, Conrad
dc.contributor.committeememberManske, Sarah
dc.contributor.committeememberFederico, Salvatore
dc.date2023-02
dc.date.accessioned2022-11-22T16:27:45Z
dc.date.available2022-11-22T16:27:45Z
dc.date.issued2022-11-16
dc.description.abstractMicrogravity-related bone loss presents a challenge to astronauts undergoing long-duration spaceflight. Astronauts undergo a period of substantial bone apposition upon return to Earth, which provides a unique opportunity to examine the mechanisms of bone remodeling. The objective of this study was to detect new trabecular bone connections in the form of topological bridging and quantify anisotropy changes in astronaut bone returning from the International Space Station (ISS). Seventeen United States Orbital Segment (USOS) astronauts participating in ISS missions of varying lengths (3.5-7 months) had their distal tibia and radius imaged using high-resolution peripheral quantitative computed tomography (HR-pQCT) before spaceflight, at landing (R+0M), and at 12 months post-flight (R+12M). Bone images were three-dimensionally rigid registered (3DR) longitudinally. A skeletonization decomposed the R+12M images to their underlying structure, allowing superimposition to the R+0M image where the difference highlighted areas of bone apposition during recovery. Anisotropy changes were tracked using mean intercept length (MIL). To compare the sensitivity of topology and anisotropy changes in astronauts, a reference was established using same-day repeat HR-pQCT distal tibia (n=90) and radius (n=89) images from control participants. The topology and anisotropy difference significance was assessed using a Wilcoxon rank-sum test between astronauts and control, while the anisotropic precision was determined from control scan root-mean-square coefficient of variation (RMSCV%). Astronauts’ group median apposition site average size was 1.2 times larger in the tibia and the same in the radius when compared to controls (p<0.01, p=0.64 respectively). Qualitatively examining the astronaut apposition sites revealed instances of bone bridging the space between two adjacent structures, indicating trabecular topological reconnection. Estimated precision for anisotropy measures from the control scans ranged from 0.9 to 1.3%, while the astronauts’ change in anisotropy ranged from -2.9 to 6.4% (group median -0.02%) during in-flight loss and -5.0 to 6.8% (group median 0.1%) during post-flight recovery. Bone resorption and apposition varied considerably between astronauts, with evidence of new topological connections across all participants. Several astronauts demonstrated a substantial change in anisotropy, suggesting directional alterations are concurrent with topology adaptation that occurs upon recovery on Earth.en_US
dc.identifier.citationMielczarek, C. (2022). An investigation of local microarchitecture topology changes in long-duration spaceflight (Master's thesis, University of Calgary, Calgary, Canada). Retrieved from https://prism.ucalgary.ca.en_US
dc.identifier.urihttp://hdl.handle.net/1880/115522
dc.identifier.urihttps://dx.doi.org/10.11575/PRISM/40480
dc.language.isoengen_US
dc.publisher.facultySchulich School of Engineeringen_US
dc.publisher.institutionUniversity of Calgaryen
dc.rightsUniversity of Calgary graduate students retain copyright ownership and moral rights for their thesis. You may use this material in any way that is permitted by the Copyright Act or through licensing that has been assigned to the document. For uses that are not allowable under copyright legislation or licensing, you are required to seek permission.en_US
dc.subjectBiomedical Engineeringen_US
dc.subjectBoneen_US
dc.subjectSpace Healthen_US
dc.subjectSpace Medicineen_US
dc.subjectAstronauten_US
dc.subjectTrabecular Boneen_US
dc.subjectTopologyen_US
dc.subjectMedical Imagingen_US
dc.subjectOsteoporosisen_US
dc.subject.classificationEngineeringen_US
dc.subject.classificationEngineering--Aerospaceen_US
dc.subject.classificationEngineering--Biomedicalen_US
dc.titleAn Investigation of Local Microarchitecture Topology Changes in Long-Duration Spaceflighten_US
dc.typemaster thesisen_US
thesis.degree.disciplineEngineering – Biomedicalen_US
thesis.degree.grantorUniversity of Calgaryen_US
thesis.degree.nameMaster of Science (MSc)en_US
ucalgary.item.requestcopytrueen_US
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