Susceptibility-matched envelope for the correction of EPI artifacts

Area of Science:

• Magnetic Resonance Imaging (MRI)
• Biophysics
• Medical Physics

Background:

• Fast gradient echo sequences like echo planar imaging (EPI) are susceptible to B(0) inhomogeneities.
• Susceptibility variations, especially at air-tissue interfaces, cause geometrical distortions and signal loss (T(2)* dephasing).
• These artifacts worsen at higher magnetic fields, negating SNR benefits.

Purpose of the Study:

• To develop an efficient method for correcting B(0) inhomogeneity artifacts in MRI.
• To address susceptibility variations at the external boundary of the human body.

Main Methods:

• Surrounding the imaged organ with a liquid lacking hydrogen atoms and matched in magnetic susceptibility.
• Conducting EPI experiments on phantoms, human brain, hand, and legs.

Main Results:

• Successfully corrected inhomogeneity caused by external susceptibility variations.
• Demonstrated minimal patient inconvenience and no interference with scanner function.
• Achieved a simple and efficient solution for B(0) variation correction.

Conclusions:

• The proposed method effectively reduces susceptibility artifacts in EPI MRI.
• This technique offers a practical solution for improving image quality in various anatomical regions.
• The approach is compatible with standard MRI scanners and patient comfort.