Finite size disc gradient coil set for open vertical field magnets

Area of Science:

• Magnetic Resonance Imaging (MRI) hardware development
• Electromagnetics and Coil Design

Background:

• Gradient coils are essential components in MRI systems, responsible for spatial encoding of the magnetic resonance signal.
• Designing efficient and effective gradient coils, particularly for specific magnet geometries, presents ongoing engineering challenges.
• Minimizing fringe fields is crucial for reducing electromagnetic interference and improving image quality.

Purpose of the Study:

• To introduce a novel analytical approach for designing disc-like gradient coils.
• To optimize coil characteristics using an inverse procedure for specific imaging volume requirements.
• To evaluate the performance of self-shielded transverse disc coils compared to non-shielded axial designs.

Main Methods:

• An inverse design procedure was employed to optimize gradient coil parameters.
• The Biot-Savart law was applied to discrete current patterns for field calculation.
• Finite Element Analysis (FEA) was utilized to predict fringe gradient field levels.

Main Results:

• Excellent agreement was observed between analytical predictions and Biot-Savart law calculations for gradient magnetic fields.
• The self-shielded transverse disc coil design demonstrated a 1000-fold reduction in gradient fringe fields compared to non-shielded designs.
• The shielded coil's fringe field exhibited minimal spatial dependence near magnet poles.

Conclusions:

• The developed analytical approach provides an effective method for designing disc-like gradient coils.
• Self-shielded transverse disc coils offer superior performance in fringe field reduction for MRI applications.
• The findings contribute to the advancement of MRI hardware for improved spatial encoding and reduced interference.