Connectivity in human cancellous bone by three-dimensional magnetic resonance imaging

Area of Science:

• Biomedical Engineering
• Orthopedics
• Medical Imaging

Background:

• Bone architecture significantly influences bone strength and fracture resistance.
• Trabecular connectivity is increasingly recognized as a critical determinant of bone quality.
• Assessing trabecular connectivity holds potential for diagnosing osteoporosis and monitoring therapeutic interventions.

Purpose of the Study:

• To apply three-dimensional magnetic resonance imaging microscopy (3D-MRI) for measuring connectivity in human cancellous bone.
• To investigate the impact of sample volume on connectivity density measurements.
• To evaluate the correlation between connectivity density and other bone metrics.

Main Methods:

• Human cancellous bone biopsies were analyzed using 3D-MRI microscopy.
• Connectivity density was measured across varying subvolume sizes to assess sample heterogeneity.
• Reproducibility was assessed through repeat measurements at constant and enhanced resolutions.

Main Results:

• Connectivity density measurements were significantly influenced by the chosen examination volume, with stable results obtained for volumes exceeding 100 mm3.
• Connectivity density showed a strong correlation with nodal density and 2D connectivity estimates, but not with bone volume fraction.
• Enhanced resolution imaging (69 x 69 x 43 microns) revealed increased apparent connectivity density while maintaining constant bone fraction.

Conclusions:

• 3D-MRI microscopy is a viable technique for quantifying trabecular connectivity in human bone.
• Standardized examination volumes are crucial for reliable connectivity density measurements.
• Trabecular connectivity, particularly at higher resolutions, offers valuable insights into bone structure and quality relevant to osteoporosis research.