Design, Fabrication and Testing of an Insertable Double-Imaging-Region Gradient Coil

Area of Science:

• Magnetic Resonance Imaging (MRI)
• Coil Design
• Gradient Systems

Background:

• Current MRI systems have limitations in field-of-view (FOV) coverage.
• Extending FOV often requires repositioning the patient or subject.
• Simultaneous multi-region imaging could enhance efficiency and reduce scan times.

Purpose of the Study:

• To construct and evaluate a two-region gradient coil insert for MRI.
• To enable simultaneous RF transmission and reception in two distinct imaging regions.
• To serve as a proof of concept for a larger, multi-region gradient system for extended FOV imaging.

Main Methods:

• Designed and optimized conductor placement for X, Y, and Z gradient coils using simulated annealing.
• Interfaced the two-region gradient coil and RF system with a Siemens 3T TIM Trio MRI scanner.
• Tested gradient homogeneity and signal crosstalk using phantoms in multiple imaging regions.

Main Results:

• Achieved low inductance, high efficiency, and reasonable homogeneity in the gradient coils.
• Acquired simultaneous images in two regions with minimal signal crosstalk.
• Demonstrated minimal signal interference from the central non-imaging region.

Conclusions:

• A functional two-region gradient coil insert was successfully constructed and tested.
• This system is a viable intermediate step towards a three-region system for extended FOV MRI.
• The technology promises seamless extended FOV imaging without table movement or increased nerve stimulation.