Gradient Nonlinearity Terms in the Concomitant Field for Quantitative Phase Contrast Correction

Ek T. Tan¹, Christopher J. Hardy¹, John F. Schenck¹

The correction of residual phase intrinsic to phase-contrast velocity measurements remains a challenging problem, and affects accurate flow quantitation in imaging of congenital heart disease. A high degree of correlation between the residual phase and the concomitant field motivated an investigation into an improved concomitant field correction that accounts for gradient nonlinearity. The nonlinear correction resulted in a residual phase that was more quadratic in shape, but did not affect the residual phase near the vessels of interest. However, the incorporation of nonlinear concomitant fields into a hybrid-fitting method showed an improvement in the fitted result over the linear correction.