Assessment of Bone Density and Microarchitecture In Vivo Using High-Resolution Peripheral Quantitative Computed Tomography
Publication Date: May 1, 2020
Last Updated: March 14, 2022
Summary of recommendations
Scan acquisition and analysis
The method of selecting scan site should be clearly indicated. The relative offset outlined in this article and described in detail elsewhere [Bonaretti S, et al.Osteoporos Int 28:2115–2128] is recommended. However, a fixed offset may be used when comparing to historical datasets.
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Image processing should use direct measurement methods following the extended cortical analysis. Automatically generated contours should be checked and manually corrected for errors following guidelines outlined in detail elsewhere [Whittier DE et al. Osteoporos Int].
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μFE analysis should use standardized constitutive properties and boundary conditions. μFE specifications outlined in Table 4 are recommended for first-generation HR-pQCT and can be compared using harmonizing techniques. For second-generation HR-pQCT analysis, an elastic modulus of 10,000 MPa with axial boundary conditions and a yield criterion of 1.0% critical strain and 5% critical volume is recommended.
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Table 4 Summary of elastic modulus, boundary conditions, and common yield criterion for first- and second-generation HR-pQCT. All models applied a 1% compressive strain in the axial direction and used a Poisson’s ratio of 0.3. Unless specified, the proposed yield criterion and associated constitutive properties were compared with mechanical compressive loading tests; however, loading configurations relative to the scan region vary across studies.
* Original validation studies were conducted using a 3D-pQCT scanner with 165 μm isotropic resolution; however, these parameter specifications have been frequently applied to first-generation HR-pQCT
† Yield criterion with associated tissue properties and boundary conditions were not explicitly validated in this study.
| Reference | Elastic modulus (MPa) | Boundary conditions | Yield criterion (critical strain, critical volume) |
| First-generation HR-pQCT | |||
| Pistoia et al. Bone. 2002/Pistoia et al. J Clin. Dens. 2004* | 10,000 | Axial | 0.7%, 2% |
| MacNeil et al. Bone 2008 | 6829 | Uniaxial | 0.7%, 2% |
| Mueller et al. Bone 2009 | 6829 | Uniaxial | 0.7%, 7.5% |
| Vilayphiou et al. Bone 2010† | Trabecular bone: 17,000 Cortical bone: 20,000 |
Axial | 0.35%, 2% |
| Second-generation HR-pQCT | |||
| Whittier et al. J Biomech 2018 | 8748 | Uniaxial | 0.7%, 2% |
| Arias-Moreno Osteoporosis Int 2019 | 10,000 | Axial | 1.0%, 5% |
† Yield criterion with associated tissue properties and boundary conditions were not explicitly validated in this study.
Longitudinal studies should employ 3D or 2D registration and exclude scans with less than 75% overlap. μFE should not be applied to 3D-registered scans and instead 2D-registered or unregistered scans should be used.
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Reporting results
Standardized nomenclature proposed here should be used for reporting results. Nomenclature proposed in Tables 2, 3, and 5 should be used, and use of direct or indirect measurement techniques should be clearly indicated. The minimum parameters to describe trabecular bone morphology should include trabecular bone volume fraction, and trabecular number, thickness, and separation; for cortical bone morphology, cortical thickness, and cortical porosity should be reported.
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Table 2 Definition, units, andmeasurement ofmethods of common whole bone and cortical microarchitecture parameters obtained from available HRpQCT
systems. Italicized parameters are the minimum set to be reported when describing cortical bone morphology.
d Superscript should be used if reporting results using the derived measurement method.
* Description of direct 3D morphological method of measurement
† Description of derived (indirect) morphological method of measurement
‡ StrAx is a derived method with analysis bone compartments defined differently than the extended cortical analysis and is not integrated into the Scanco workflow
Ideally the minimum set of parameters reported are bolded.
* Description of direct 3D morphological method of measurement
† Description of derived (indirect) morphological method of measurement
‡ StrAx is a derived method with analysis bone compartments defined differently than the extended cortical analysis and is not integrated into the Scanco workflow
Ideally the minimum set of parameters reported are bolded.
Table 3 Definition, units, and measurement of methods of common trabecular microarchitecture parameters obtained from available HR-pQCT
systems. Italicized parameters are the minimum set to be reported when describing trabecular bone morphology.
d Superscript should be used if reporting results using the derived measurement method.
* Description of direct 3D morphological method of measurement
† Description of derived (indirect) morphological method of measurement
Ideally the minimum set of parameters reported are bolded.
* Description of direct 3D morphological method of measurement
† Description of derived (indirect) morphological method of measurement
Ideally the minimum set of parameters reported are bolded.
Table 5 Definition, units, and measurement of methods of common micro-finite element analysis outcomes obtained from available HR-pQCT systems
* These properties are scalar values defined for each element. Properties can be visualized on the model to inspect localized stress and strains, or expressed in terms of histograms. The average or median value across the model can be reported, and the histogram skewness or kurtosis can be used to provide insight into the strain distributions in the context of bone adaptation.
Precision error should be measured and reported for each research center, specific to study protocol. Cross-sectional studies should report precision with unregistered scans, and longitudinal studies should report precision with the registration technique used in the study design.
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Quality control and training
Quality control should follow manufacturer maintenance protocol, including daily and weekly scanning of QC phantoms. Scanner drift should be actively monitored, and the use of Shewhart charts to track scanner stability is recommended.
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New operators should be trained by an experienced operator and available training tools used. New operators should be trained in patient management and positioning, anatomical measurements, location of the reference line, and manual correction of contours generated by the automated and semi-automated protocols. Training should be supplemented with online reference line training developed by UCSF [Bonaretti S et al. Osteoporos Int 28: 245–257], and other online resources, as they become available.
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Continuity across scanner generations (makes, models) should be assessed through cross-calibration. It is important to understand relationships between parameters measured on different scanner generations [Agarwal S et al. Osteoporos Int 27:2955–2966, Manske SL et al. J Bone Miner Res 32:1514–1524]. Typically, density-based parameters can be converted between scanner generations, but resolution-dependent parameters (e.g., Tb.Th) are problematic and should not be compared between generations.
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Multi-center studies should report inter-scanner precision error, and it is recommended that these are estimated using a calibration phantom that replicates geometry, densities, and microarchitecture of standard scan sites.
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Recommendation Grading
Overview
Title
Assessment of Bone Density and Microarchitecture In Vivo Using High-Resolution Peripheral Quantitative Computed Tomography
Authoring Organization
Publication Month/Year
May 1, 2020
Last Updated Month/Year
August 29, 2024
Document Type
Guideline
External Publication Status
Published
Country of Publication
US
Inclusion Criteria
Female, Male, Adult, Older adult
Health Care Settings
Ambulatory, Hospital, Radiology services
Intended Users
Physical therapist, clinical researcher, nurse, nurse practitioner, physician, physician assistant
Scope
Assessment and screening, Diagnosis
Diseases/Conditions (MeSH)
D015519 - Bone Density
Keywords
Bone microarchitecture, High-resolution peripheral quantitative computed tomography (HR-pQCT) , bone density
Source Citation
Whittier, D. E., Boyd, S. K., Burghardt, A. J., Paccou, J., Ghasem-Zadeh, A., Chapurlat, R., … Bouxsein, M. L. (2020). Guidelines for the assessment of bone density and microarchitecture in vivo using high-resolution peripheral quantitative computed tomography. Osteoporosis International. doi:10.1007/s00198-020-05438-5