Quiet MRI with novel acoustic noise reduction

Area of Science:

• Medical Imaging
• Acoustics
• Biomedical Engineering

Background:

• Fast scanning techniques in magnetic resonance imaging (MRI) increase noise levels, causing patient discomfort.
• MRI noise originates from gradient coil vibrations induced by Lorentz forces from electrical currents within the static magnetic field.
• Current MRI systems lack effective noise reduction strategies, impacting patient experience.

Purpose of the Study:

• To investigate methods for substantially reducing acoustic noise generated by MRI systems.
• To develop a "silent" MRI system that minimizes patient discomfort during examinations.
• To identify key sources of vibration and noise within the MRI hardware.

Main Methods:

• Implementing a vacuum chamber to encapsulate the gradient coil, thereby blocking airborne vibration propagation.
• Independently supporting the gradient coil structure to mitigate solid-borne vibration transmission.
• Reducing eddy currents induced in radiofrequency (RF) coils, RF shielding, and the static-field-magnet cryostat.

Main Results:

• Significant reduction in MRI scanning noise was achieved through the implemented methods.
• The developed silent MRI system demonstrated markedly reduced noise levels across various scanning conditions.
• The combined strategies effectively addressed both airborne and solid-borne vibration pathways.

Conclusions:

• Sealing the gradient coil in a vacuum and independent support structures are effective in reducing MRI noise.
• Minimizing eddy currents further contributes to noise reduction in MRI systems.
• The developed silent MRI system offers a more comfortable experience for patients undergoing magnetic resonance imaging.