Practical estimate of gradient nonlinearity for implementation of apparent diffusion coefficient bias correction.

ABSTRACT:

Purpose

To describe an efficient procedure to empirically characterize gradient nonlinearity and correct for the corresponding apparent diffusion coefficient (ADC) bias on a clinical magnetic resonance imaging (MRI) scanner.

Materials and methods

Spatial nonlinearity scalars for individual gradient coils along superior and right directions were estimated via diffusion measurements of an isotropicic e-water phantom. Digital nonlinearity model from an independent scanner, described in the literature, was rescaled by system-specific scalars to approximate 3D bias correction maps. Correction efficacy was assessed by comparison to unbiased ADC values measured at isocenter.

Results

Empirically estimated nonlinearity scalars were confirmed by geometric distortion measurement

SUBMITTER: Malkyarenko DI 

PROVIDER: S-EPMC4324556 | biostudies-literature | 2014 Dec

REPOSITORIES: biostudies-literature