Error Analysis and Correction of ADC Measurements for Gradient Non-Linearity

Dariya I. Malyarenko¹, Brian D. Ross¹, Thomas L. Chenevert¹

Gradient non-linearity leads to spatially-dependent b-values and consequently significant non-uniformity error (~10-20%) in ADC measurements over clinically-relevant FOVs. For quantitative analysis of ADC errors, a gradient correction tensor model of spatially-dependent gradient fields was used. The model included the effect of imaging gradients, gradient cross-terms and their influence in presence of media anisotropy. All-inclusive error analysis allowed finding minimal number of spatial correction terms to achieve sufficient ADC error reduction (by 75-95%) for tissue-like diffusion anisotropy. Simplified ADC correction algorithm is suggested for implementation on MR systems based on known gradient hardware properties