Practical Aspects of Correcting ADC Bias Due to Gradient Nonlinearity in Media of Arbitrary Anisotropy

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

Relatively large ADC bias error, well exceeding measurement noise, can be observed for anatomical regions imaged distant from magnet isocenter. Gradient nonlinearity is a main source of bias. Our previously-described approach allowed substantial reduction of spatial ADC bias for media of arbitrary anisotropy using DWI encoding along any three orthogonal directions. This work focuses on practical aspects of ADC correction implementation via system nonlinearity tensor for derivation of correctors applicable to DWI or b-map generation. Correction performance was evaluated for isotropic and anisotropic media.