Experimental evaluation of nonlinearities of small-sized insertable gradient coils

Area of Science:

• Magnetic Resonance Imaging
• Gradient Coil Engineering
• Image Reconstruction

Background:

• Accurate gradient performance is critical for magnetic resonance imaging (MRI) quality.
• Nonlinearities in gradient coils can degrade image resolution and introduce artifacts.
• Characterizing these nonlinearities, especially in insertable coils, is essential for reliable imaging.

Purpose of the Study:

• To develop and validate a phase imaging technique for mapping and quantifying gradient nonlinearities.
• To assess the performance of small-sized insertable gradient coils.
• To provide a method for precise local and regional quantification of gradient nonlinearities.

Main Methods:

• Theoretical development of a phase imaging approach.
• Derivation of simple equations for quantitative analysis.
• Application to a 4-loop, 18-cm diameter cylindrical gradient coil.
• Experimental acquisition of gradient nonlinearity maps across various fields of view.

Main Results:

• Successful mapping of experimental gradient nonlinearities.
• Quantification of nonlinearities locally and within specific regions of interest.
• Demonstrated close agreement between experimental data and model predictions.
• Validation of the phase imaging technique for insertable gradient coils.

Conclusions:

• The proposed phase imaging technique effectively maps and quantifies gradient nonlinearities in small insertable gradient coils.
• The method provides accurate, localized measurements crucial for coil characterization.
• This technique supports the development and quality assurance of advanced MRI hardware.