Prospective compensation of second-order concomitant fields in a high-performance gradient system using a...

Area of Science:

• Magnetic Resonance Imaging (MRI)
• Gradient Coil Technology
• Biomedical Engineering

Background:

• High-performance gradient coils in MRI generate stronger concomitant magnetic fields.
• These fields cause artifacts like signal dropout, blurring, and phase errors, particularly away from the gradient isocenter.
• Existing methods for correcting these errors are often applied during image reconstruction.

Purpose of the Study:

• To describe a novel correction coil for prospectively compensating second-order concomitant fields.
• To evaluate the efficacy of this coil in a high-performance head-only gradient system at 3.0T.

Main Methods:

• Development of an insertable, axially symmetric second-order field correction coil.
• Testing the coil's performance using phantom and healthy volunteer scans.
• Utilizing 2D phase contrast (PC) and spiral gradient echo (GRE) imaging techniques.

Main Results:

• Significant reduction in blurring, phase errors, and signal degradation in spiral GRE and PC images.
• 100% and 83% reduction in specific second-order concomitant phase errors in PC acquisitions.
• Up to 968.9% signal enhancement in two-sided PC acquisitions.
• Approximately 40.2% reduction in blurring in phantom spiral GRE images at 60mm from isocenter.

Conclusions:

• The developed correction coil effectively compensates for second-order concomitant field-induced phase errors at the source.
• This prospective compensation complements or potentially replaces post-acquisition software corrections.
• The technology enhances image quality in high-performance MRI systems.