Hongfu Sun1,2, Jon O Cleary3,4, Rebecca Glarin3, Scott C Kolbe3,5, Roger J Ordidge3, Bradford A Moffat3, G Bruce Pike2. 1. School of Information Technology and Electrical Engineering, University of Queensland, Brisbane, Queensland, Australia. 2. Department of Radiology, University of Calgary, Calgary, Alberta, Canada. 3. Department of Medicine and Radiology, University of Melbourne, Parkville, Victoria, Australia. 4. Department of Radiology, Guy's and St. Thomas' NHS Foundation Trust, London, UK. 5. Department of Neuroscience, Monash University, Melbourne, Victoria, Australia.
Abstract
PURPOSE: To demonstrate simultaneous T1 -weighted imaging, T1 mapping, R 2 ∗ mapping, SWI, and QSM from a single multi-echo (ME) MP2RAGE acquisition. METHODS: A single-echo (SE) MP2RAGE sequence at 7 tesla was extended to ME with 4 bipolar gradient echo readouts. T1 -weighted images and T1 maps calculated from individual echoes were combined using sum of squares and averaged, respectively. ME-combined SWI and associated minimum intensity projection images were generated with TE-adjusted homodyne filters. A QSM reconstruction pipeline was used, including a phase-offsets correction and coil combination method to properly combine the phase images from the 32 receiver channels. Measurements of susceptibility, R 2 ∗ , and T1 of brain tissue from ME-MP2RAGE were compared with those from standard ME-gradient echo and SE-MP2RAGE. RESULTS: The ME combined T1 -weighted, T1 map, SWI, and minimum intensity projection images showed increased SNRs compared to the SE results. The proposed coil combination method led to QSM results free of phase-singularity artifacts, which were present in the standard adaptive combination method. T1 -weighted, T1 , and susceptibility maps from ME-MP2RAGE were comparable to those obtained from SE-MP2RAGE and ME-gradient echo, whereas R 2 ∗ maps showed increased blurring and reduced SNR. T1 , R 2 ∗ , and susceptibility values of brain tissue from ME-MP2RAGE were consistent with those from SE-MP2RAGE and ME-gradient echo. CONCLUSION: High-resolution structural T1 weighted imaging, T1 mapping, R 2 ∗ mapping, SWI, and QSM can be extracted from a single 8.5-min ME-MP2RAGE acquisition using a customized reconstruction pipeline. This method can be applied to replace separate SE-MP2RAGE and ME-gradient echo acquisitions to significantly shorten total scan time.
PURPOSE: To demonstrate simultaneous T1 -weighted imaging, T1 mapping, R 2 ∗ mapping, SWI, and QSM from a single multi-echo (ME) MP2RAGE acquisition. METHODS: A single-echo (SE) MP2RAGE sequence at 7 tesla was extended to ME with 4 bipolar gradient echo readouts. T1 -weighted images and T1 maps calculated from individual echoes were combined using sum of squares and averaged, respectively. ME-combined SWI and associated minimum intensity projection images were generated with TE-adjusted homodyne filters. A QSM reconstruction pipeline was used, including a phase-offsets correction and coil combination method to properly combine the phase images from the 32 receiver channels. Measurements of susceptibility, R 2 ∗ , and T1 of brain tissue from ME-MP2RAGE were compared with those from standard ME-gradient echo and SE-MP2RAGE. RESULTS: The ME combined T1 -weighted, T1 map, SWI, and minimum intensity projection images showed increased SNRs compared to the SE results. The proposed coil combination method led to QSM results free of phase-singularity artifacts, which were present in the standard adaptive combination method. T1 -weighted, T1 , and susceptibility maps from ME-MP2RAGE were comparable to those obtained from SE-MP2RAGE and ME-gradient echo, whereas R 2 ∗ maps showed increased blurring and reduced SNR. T1 , R 2 ∗ , and susceptibility values of brain tissue from ME-MP2RAGE were consistent with those from SE-MP2RAGE and ME-gradient echo. CONCLUSION: High-resolution structural T1 weighted imaging, T1 mapping, R 2 ∗ mapping, SWI, and QSM can be extracted from a single 8.5-min ME-MP2RAGE acquisition using a customized reconstruction pipeline. This method can be applied to replace separate SE-MP2RAGE and ME-gradient echo acquisitions to significantly shorten total scan time.
Authors: Tianle Cao; Sen Ma; Nan Wang; Sara Gharabaghi; Yibin Xie; Zhaoyang Fan; Elliot Hogg; Chaowei Wu; Fei Han; Michele Tagliati; E Mark Haacke; Anthony G Christodoulou; Debiao Li Journal: Magn Reson Med Date: 2021-10-27 Impact factor: 3.737
Authors: Matthew F Glasser; Timothy S Coalson; Michael P Harms; Junqian Xu; Graham L Baum; Joonas A Autio; Edward J Auerbach; Douglas N Greve; Essa Yacoub; David C Van Essen; Nicholas A Bock; Takuya Hayashi Journal: Neuroimage Date: 2022-06-10 Impact factor: 7.400
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