Design of a double breast gradient coil with controlled anterior posterior gradient variation for diffusion weighted imaging

TL;DR

This paper presents an optimization framework for designing local gradient coils that enhance breast DWI imaging by increasing efficiency and controlling gradient variation, validated through prototype experiments.

Contribution

It introduces a novel coil design optimization method with a constraint on gradient variation, improving efficiency and uniformity over previous designs.

Findings

Achieved a 2.35-fold efficiency increase over standard coils.

Reduced spatial variation by 35.7% compared to previous nonlinear designs.

Experimental field maps matched simulations with errors under 8%.

Abstract

Introduction High performance gradients poses a promise for breast diffusion weighted imaging (DWI) but are restricted by physiological limits in whole body scanners. While local nonlinear coils offer higher amplitudes, they often suffer from severe gradient reduction near the chest wall. Methods We introduced an optimization framework incorporating a constraint to control anterior posterior gradient variation. A width based figure of merit was defined to evaluate performance regarding coil efficiency and minimum wire width. A prototype was constructed to validate the design methodology. Results The optimized coil achieved a 2.35 fold efficiency increase over standard linear coils. Compared to previous nonlinear designs, the new constraint reduced spatial variation by 35.7% and improved minimum efficiency near the chest wall by 2.6 fold. Experimental field maps matched simulations with errors under 8%. Discussion The proposed method effectively mitigates the trade-off between gradient strength and spatial uniformity along anterior posterior direction. By enhancing performance in the posterior breast region, the design addresses a critical limitation of previous local coils. Conclusion This framework enables the development of high performance, robust local gradient coils, facilitating the clinical implementation of advanced DWI protocols for breast cancer screening.