Hong-Hsi Lee1, Dmitry S Novikov1, and Els Fieremans1
1New York University School of Medicine, New York, NY, United States
1New York University School of Medicine, New York, NY, United States
We investigate and remove the Gibbs-ringing artifact caused by partial Fourier (PF) acquisition and zero filling interpolation in MRI data. With the understanding of oscillating convolution kernels due to the PF acquisition, the ringings in magnitude images can be robustly removed.
Fig 3. Numerical simulations of Gibbs-ringing removal in 2D magnitude images of the Shepp-Logan phantom with phase. The first two rows show images of the signal magnitude before and after ringing removal, and the third row shows residual maps. For pf = 7/8 and 6/8, the RPG pipeline robustly removes PF-induced ringings, whereas for pf = 5/8 the corrected image still has non-trivial amount of ringings after applying RPG, potentially caused by the interaction of the images phase in high resolution ground truth and the convolution kernel in Eq. (1).
Fig 4. Mean diffusivity (MD) map baed on diffusion-weighted-images (DWIs) before and after Gibbs-ringing removal using local subvoxel-shifts (SuShi) and RPG, with the residual of MD before and after corrections. The unit of MD is $$$\mu$$$m$$$^2$$$/ms.