Melbourne Brain Centre Imaging Unit, The University of Melbourne, Australia; Department of Biomedical Engineering, The University of Melbourne, Australia
Warda T. Syeda
Melbourne Neuropsychiatry Centre, The University of Melbourne, Australia; Department of Medicine and Radiology, The University of Melbourne, Australia
Chengchuan Wu
Melbourne Brain Centre Imaging Unit, The University of Melbourne, Australia; Department of Biomedical Engineering, The University of Melbourne, Australia
Yicheng Zhang
Melbourne Brain Centre Imaging Unit, The University of Melbourne, Australia; Department of Biomedical Engineering, The University of Melbourne, Australia
Tracy D. Zhang
Florey Institute of Neuroscience and Mental Health, Australia
Emma L. Burrows
Florey Institute of Neuroscience and Mental Health, Australia
Amy Brodtmann
Florey Institute of Neuroscience and Mental Health, Australia
Bradford A. Moffat
Melbourne Brain Centre Imaging Unit, The University of Melbourne, Australia; Department of Medicine and Radiology, The University of Melbourne, Australia
David K. Wright
Department of Neuroscience, Central Clinical School, Monash University, Australia
Rebecca Glarin
Melbourne Brain Centre Imaging Unit, The University of Melbourne, Australia; Department of Radiology, Royal Melbourne Hospital, Australia
Scott Kolbe
Department of Medicine and Radiology, The University of Melbourne, Australia; Department of Neuroscience, Central Clinical School, Monash University, Australia; Department of Radiology, Alfred Hospital, Australia
Leigh A. Johnston
Melbourne Brain Centre Imaging Unit, The University of Melbourne, Australia; Department of Biomedical Engineering, The University of Melbourne, Australia; Department of Medicine and Radiology, The University of Melbourne, Australia; Corresponding author at: Melbourne Brain Centre Imaging Unit, The University of Melbourne, Melbourne, VIC, Australia.
Purpose: Quantitative susceptibility mapping (QSM) is a novel MR technique that allows mapping of tissue susceptibility values from MR phase images. QSM is an ill-conditioned inverse problem, and although several methods have been proposed in the field, in the presence of a wide range of susceptibility sources, streaking artifacts appear around high susceptibility regions and contaminate the whole QSM map. QSMART is a post-processing pipeline that uses two-stage parallel inversion to reduce the streaking artifacts and remove banding artifact at the cortical surface and around the vasculature. Method: Tissue and vein susceptibility values were separately estimated by generating a mask of vasculature driven from the magnitude data using a Frangi filter. Spatially dependent filtering was used for the background field removal step and the two susceptibility estimates were combined in the final QSM map. QSMART was compared to RESHARP/iLSQR and V-SHARP/iLSQR inversion in a numerical phantom, 7T in vivo single and multiple-orientation scans, 9.4T ex vivo mouse data, and 4.7T in vivo rat brain with induced focal ischemia. Results: Spatially dependent filtering showed better suppression of phase artifacts near cortex compared to RESHARP and V-SHARP, while preserving voxels located within regions of interest without brain edge erosion. QSMART showed successful reduction of streaking artifacts as well as improved contrast between different brain tissues compared to the QSM maps obtained by RESHARP/iLSQR and V-SHARP/iLSQR. Conclusion: QSMART can reduce QSM artifacts to enable more robust estimation of susceptibility values in vivo and ex vivo.
