Variability in Ultrasound Backscatter Induced by Trabecular Microstructure Deterioration in Cancellous Bone

Area of Science:

• Biomedical Engineering
• Materials Science
• Orthopedics

Background:

• Cancellous bone microstructure significantly influences mechanical properties.
• Assessing bone microarchitecture non-invasively is crucial for diagnosing and managing bone diseases.
• Current methods for evaluating bone microstructure have limitations.

Purpose of the Study:

• To investigate the relationship between ultrasonic backscatter parameters and cancellous bone microstructural variations.
• To simulate changes in cancellous bone microstructure using erosion procedures.
• To analyze how porosity and trabecular orientation affect ultrasonic backscatter.

Main Methods:

• Simulations of ultrasonic backscatter signals in cancellous bone using the finite difference time domain (FDTD) method.
• Derivation of ultrasonic backscatter properties (apparent backscatter coefficient - ABC, apparent integrated backscatter - AIB) as functions of porosity.
• Analysis of backscatter parameter variations with respect to ultrasound incident direction (perpendicular and parallel to the major trabeculae direction - MTD).

Main Results:

• Significant negative correlations were observed between ABC, AIB, and cancellous bone porosity.
• Ultrasonic backscatter parameters (ABC and AIB) were influenced by the direction of trabecular microstructural variations.
• Linear regressions revealed significantly different slopes for ABC and AIB with respect to porosity under different erosion procedures and ultrasound incidence angles relative to the MTD.

Conclusions:

• Ultrasonic backscatter parameters show a strong relationship with cancellous bone microstructure deterioration.
• The direction of microstructural changes significantly impacts ultrasonic backscatter.
• Ultrasonic backscatter holds potential as a non-invasive method for assessing cancellous bone health and detecting microstructural changes.