Meeting Banner
Abstract #2474

Efficient Concomitant Field Artifacts Reduction Using a Hybrid Space-Frequency Domain Formulism

Yi-Cheng Hsu1, Panu T. Vesanen2, Jaakko O. Nieminen2, Koos C. J. Zevenhoven2, Juhani Dabek2, I-Liang Chern3, Risto J. Ilmoniemi4, Fa-Hsuan Lin3, 5

1National Taiwan University, Taipei, Taiwan; 2Aalto University, Finland; 3National Taiwan University, Taiwan; 4Aalto University, Taiwan; 5Massachusetts General Hospital, United States

To mitigate the challenge of reconstructing MRI data deteriorated by concomitant fields, we develop a hybrid space-frequency (x-f) domain method to i) accurately describe the dynamics of spatially encoded magnetization allowing arbitrary directions of initial magnetization and phase/frequency encoding magnetic fields, and (ii) reconstructed images using combined fast Fourier transform and a linear equation solver. We demonstrate this method in ultra-low-field MRI reconstruction when the largest concomitant field is as strong as B0.

Keywords

accurately advantages alternatively amplitude applied arbitrary artifacts becomes beginning best black blue brain calibrated capture cause coil coils compatibility component computational concomitant condition considering consists constant constraint contrast coordinate coordinates corrected cost curve cyan define denotes density describe describing description desired detectable distortion distributed distribution domain dynamics efficient either encoded encoding equation even expected experiment experimental fast field fields formalism frequency full function generated geometry gradient gradients grid horizontal hybrid ideal initial integration interpolated inverted lighter linear local location longer loss magnetization magnetizations matrix metal minimize national neglected neighboring nonlinear numerical objects orange parallel part particularly perpendicular pick polarizing potential practically precession prior procedure projected propose quantitative read real reconstructed reconstruction reconstructions reduces reduction regularization related relationship repeated sensitivity simulated simulation solve solver space spatial spatially specifically spin stages step steps strength strong subsequently sweep takes taking together traditional transform transformed tuned ultra uniform unit useful variations vector vectors whole whose