Improved Fetal Magnetic Resonance Imaging Using a Flexible Metasurface.

Area of Science:

• Medical Imaging
• Biophysics
• Materials Science

Background:

• Magnetic resonance imaging (MRI) is advancing for fetal abnormality detection, potentially replacing ultrasound.
• High-field 3 Tesla (3T) MRI offers superior image quality but suffers from increased dielectric artifacts.
• These artifacts stem from standing wave interference at higher radiofrequency fields.

Purpose of the Study:

• To introduce a novel passive radiofrequency (RF) shimming technique for fetal MRI at 3T.
• To enhance radiofrequency magnetic field homogeneity and efficiency.
• To reduce dielectric artifacts in fetal MRI scans.

Main Methods:

• Development of metasurface-based pads for passive RF shimming.
• Application of these pads in 3T MRI examinations of fetal subjects.
• Evaluation of image quality improvements, focusing on artifact reduction and signal homogeneity.

Main Results:

• The metasurface pads effectively increased the efficiency and homogeneity of the RF magnetic field.
• Significant reduction in dielectric artifacts was observed in fetal body and brain images.
• Improved image quality was achieved without active components or complex adjustments.

Conclusions:

• Metasurface-based passive RF shimming is a viable strategy to improve 3T fetal MRI.
• This approach offers an ultralight, compact, and passive solution for enhancing prenatal imaging.
• The technique has the potential to simplify clinical workflows and reduce examination times.