A new technique for motion encoding gradient-less MR elastography of the psoas major muscle: A gradient-echo type...

Area of Science:

• Biomedical Engineering
• Musculoskeletal Imaging
• Medical Physics

Background:

• Non-specific low back pain (LBP) is often associated with increased muscle stiffness.
• Quantitative assessment of muscle stiffness in the psoas major muscle (PM) is crucial for understanding LBP.
• Conventional magnetic resonance elastography (MRE) techniques may require specialized equipment.

Purpose of the Study:

• To develop and validate novel vibration techniques for MRE of the PM.
• To assess the feasibility of using a 3D-printed pneumatic vibration pad for PM MRE.
• To establish a quantitative diagnostic method for PM stiffness related to LBP.

Main Methods:

• Developed a 3D-printed narrow vibration pad for pneumatic vibration transmission.
• Utilized a motion-encoding gradient (MEG)-less multi-echo MRE sequence suitable for conventional MRI scanners.
• Applied vibration techniques to seven healthy volunteers in a supine position with the pad placed under the lumbar spine.

Main Results:

• The developed vibration pad effectively transmitted vibrations to the PM via the lumbar spine.
• MRE successfully quantified the shear modulus of the PM in healthy volunteers.
• Mean shear modulus values were 1.23 ± 0.09 kPa (right) and 1.22 ± 0.15 kPa (left), with no significant side-to-side difference.

Conclusions:

• The novel vibration techniques enable effective MRE of the PM using a simple setup.
• This method provides a quantitative assessment of PM stiffness.
• The developed MRE technique serves as a potential diagnostic tool for evaluating muscle stiffness in non-specific LBP.