Stability of Gradient Field Corrections for Quantitative Diffusion MRI
Baxter P. Rogers, Justin Blaber, E. Brian Welch, Zhaohua Ding, Adam W. Anderson, Bennett A. Landman. “Stability of Gradient Field Corrections for Quantitative Diffusion MRI” In Proceedings of the SPIE Medical Imaging Conference. Orlando, Florida, February 2017.
In diffusion-weighted MRI, gradient nonlinearity causes significant bias in the estimation of quantitative diffusion parameters such as diffusivity, anisotropy, and diffusion direction. We measured the gradient stability over time. Over the course of one month the change in these quantities due to calibration-related factors was <0.5% for b-values, and <0.5 degrees for angular deviation. The proposed calibration procedure allows the estimation of gradient nonlinearity to correct b-values and gradient directions ahead of advanced diffusion image processing for high angular resolution data, and requires only a five-minute phantom scan that can be included in a weekly or monthly quality assurance protocol.