In vivo trabecular bone morphologic and mechanical relationship using high-resolution 3-T MRI

Area of Science:

• Orthopedics and Biomedical Engineering
• Radiology and Medical Imaging
• Bone Biology and Mechanics

Background:

• Trabecular bone morphology and elastic properties are crucial for skeletal integrity.
• High-resolution magnetic resonance imaging (MRI) offers a non-invasive method to assess these properties in vivo.
• Understanding the relationship between bone structure and mechanical function is vital for diagnosing and managing bone diseases.

Purpose of the Study:

• To investigate the in vivo morphologic and elastic parameters of trabecular bone using high-resolution 3-Tesla (3T) MRI.
• To establish a reference dataset in a healthy population.
• To explore the relationships between morphologic parameters, elastic properties, and influencing factors like sex and age.

Main Methods:

• Acquisition of high-spatial-resolution (180 µm isotropic voxels) wrist MRI scans from 40 healthy subjects.
• Morphologic analysis including bone volume-to-total volume ratio (BV/TV), trabecular thickness, separation, and number.
• Mechanical simulation using finite-element analysis to determine apparent elastic modulus and investigation of relationships between parameters and bone volume.

Main Results:

• Statistically significant sex-based differences were observed, with women exhibiting lower BV/TV, trabecular thickness, and apparent elastic modulus.
• Age did not show a statistically significant influence on any measured morphologic or elastic parameters.
• A strong positive correlation was found between apparent elastic modulus and the square of BV/TV (r = 0.968, p < 0.001), with results significantly differing when analyzed bone volume was reduced.

Conclusions:

• Trabecular bone morphologic parameters (BV/TV, trabecular thickness) and apparent elastic modulus are significantly influenced by sex.
• Apparent elastic modulus is strongly related to BV/TV, highlighting the importance of bone volume in mechanical assessments.
• Maximizing the analyzed trabecular bone volume is essential for accurate mechanical property evaluation.