• Yan Wen, Pascal Spincemaille, Thanh Nguyen, Junghun Cho, Ilhami Kovanlikaya, Julie Anderson, Gaohong Wu, Baolian Yang, Maggie Fung, Ke Li, Douglas Kelley, Nissim Benhamo, and Yi Wang.
• Meinig School of Biomedical Engineering, Cornell University, Ithaca, New York, USA.
• Magn Reson Med. 2021 Oct 1; 86 (4): 2165-2178.

PurposeTypical quantitative susceptibility mapping (QSM) reconstruction steps consist of first estimating the magnetization field from the gradient-echo images, and then reconstructing the susceptibility map from the estimated field. The errors from the field-estimation steps may propagate into the final QSM map, and the noise in the estimated field map may no longer be zero-mean Gaussian noise, thus, causing streaking artifacts in the resulting QSM. A multiecho complex total field inversion (mcTFI) method was developed to compute the susceptibility map directly from the multiecho gradient echo images using an improved signal model that retains the Gaussian noise property in the complex domain. It showed improvements in QSM reconstruction over the conventional field-to-source inversion.MethodsThe proposed mcTFI method was compared with the nonlinear total field inversion (nTFI) method in a numerical brain with hemorrhage and calcification, the numerical brains provided by the QSM Challenge 2.0, 18 brains with intracerebral hemorrhage scanned at 3T, and 6 healthy brains scanned at 7T.ResultsCompared with nTFI, the proposed mcTFI showed more accurate QSM reconstruction around the lesions in the numerical simulations. The mcTFI reconstructed QSM also showed the best image quality with the least artifacts in the brains with intracerebral hemorrhage scanned at 3T and healthy brains scanned at 7T.ConclusionThe proposed multiecho complex total field inversion improved QSM reconstruction over traditional field-to-source inversion through better signal modeling.© 2021 International Society for Magnetic Resonance in Medicine.

11 keywords...

hide…