Characterization of the trabecular bone structure using frequency modulated ultrasound pulse

Area of Science:

• Biomedical Engineering
• Orthopedics
• Medical Imaging

Background:

• Osteoporosis diagnosis relies on bone density measurements.
• Early detection of osteoporosis is crucial for effective intervention.
• Current ultrasound methods for bone assessment have limitations.

Purpose of the Study:

• To evaluate the efficacy of modulated ultrasound signals for measuring bone properties.
• To assess modulated ultrasound as an early indicator of osteoporosis.
• To compare frequency modulated attenuation (FMA) with broadband ultrasound attenuation (BUA).

Main Methods:

• Trabecular bone cubes from sheep femora were analyzed using micro-CT for bone volume fraction (BV/TV), trabecular thickness (Tb.Th), and trabecular separation (Tb.Sp).
• Ultrasound tests were conducted in three orthogonal orientations (SI, AP, ML) using pulse and frequency modulated ultrasound.
• Frequency modulated attenuation (FMA) was compared to broadband ultrasound attenuation (BUA) between 300-700 kHz.

Main Results:

• FMA demonstrated stronger correlations with bone structure properties in the superior-inferior (SI) orientation compared to BUA.
• In the SI orientation, FMA showed high R(2) values for BV/TV (0.84), Tb.Th (0.77), and Tb.Sp (0.7).
• In the antero-posterior (AP) orientation, FMA showed a higher correlation to Tb.Sp (R(2)=0.64) than BUA (R(2)=0.48).

Conclusions:

• Frequency modulated attenuation (FMA) shows potential as a new ultrasound index for bone property assessment.
• FMA may serve as an effective early indicator for osteoporosis.
• Modulated ultrasound signals offer improved characterization of bone structure compared to traditional BUA.