Magnetic resonance elastography with guided pressure waves.

Area of Science:

• Biomedical Engineering
• Medical Imaging
• Rheology

Background:

• Magnetic resonance elastography (MRE) is a non-invasive imaging technique for characterizing tissue mechanical properties.
• Current MRE methods face challenges in applying mechanical excitation to deep or protected organs like the brain.
• Existing techniques for brain MRE often rely on external methods like cranial bone vibration.

Purpose of the Study:

• To develop and validate a novel MRE approach for in vivo mechanical property mapping of the human brain.
• To overcome the limitations of external mechanical wave induction for brain imaging.
• To enable quantitative assessment of brain tissue viscoelasticity.

Main Methods:

• A new method was developed to guide pressure waves within the subject's buccal cavity.
• These pressure waves were transmitted through the brainstem to induce mechanical waves in the brain.
• Magnetic resonance elastography was used to record displacement fields and extract quantitative mechanical outcomes.

Main Results:

• Repeatable, reproducible, and robust displacement fields were successfully recorded in both phantoms and in vivo.
• The novel technique allowed for quantitative mechanical property extraction in the human brain.
• The method demonstrated the feasibility of circumventing the skull for brain MRE.

Conclusions:

• Guided pressure waves via the buccal cavity offer a promising non-invasive approach for MRE of the brain.
• This technique overcomes the challenge of accessing the brain for mechanical property assessment.
• The findings pave the way for advanced in vivo characterization of brain biomechanics.