Assessing Intervertebral Disk Tissue Mechanics Using Dual-Actuator Multifrequency Magnetic Resonance Elastography:...

Area of Science:

• Biomedical Engineering
• Radiology
• Orthopedics

Background:

• Degenerative disc disease (DDD) involves the progressive degeneration of intervertebral discs (IVDs), altering their mechanical properties.
• Assessing these mechanical changes is crucial for improving DDD diagnosis and treatment.
• Multifrequency magnetic resonance elastography (MMRE) offers a potential method for evaluating IVD mechanical properties in vivo.

Observation:

• MMRE was applied to the lumbar spine of three asymptomatic male volunteers (ages 32, 50, 60).
• The technique utilized a dual-actuator setup across four frequencies (60-90 Hz).
• MMRE data were processed using the k-MDEV inversion algorithm to determine shear wave speed (SWS).

Findings:

• A significant inverse correlation (ρ = -0.792, p < 0.001) was observed between IVD stiffness (measured by SWS) and the degree of disc degeneration (Pfirrmann grade).
• Increasing IVD stiffness correlated with less degeneration, while decreased stiffness indicated more advanced DDD.
• MMRE successfully measured in vivo mechanical properties of human IVDs.

Implications:

• MMRE provides valuable mechanical insights into IVD degeneration beyond conventional morphological assessments.
• This technique may enhance the diagnostic capabilities for degenerative disc disease.
• Further research is needed to establish the reproducibility, repeatability, and potential confounders of spinal MMRE before clinical adoption.