Model-based reconstruction for looping-star MRI.

Autor: Xiang H; EECS, University of Michigan, Ann Arbor, Michigan, USA., Fessler JA; EECS, University of Michigan, Ann Arbor, Michigan, USA.; Biomedical Engineering, University of Michigan, Ann Arbor, Michigan, USA., Noll DC; Biomedical Engineering, University of Michigan, Ann Arbor, Michigan, USA.
Jazyk: angličtina
Zdroj: Magnetic resonance in medicine [Magn Reson Med] 2024 May; Vol. 91 (5), pp. 2104-2113. Date of Electronic Publication: 2024 Jan 28.
DOI: 10.1002/mrm.29927
Abstrakt: Purpose: The aim of this study was to develop a reconstruction method that more fully models the signals and reconstructs gradient echo (GRE) images without sacrificing the signal to noise ratio and spatial resolution, compared to conventional gridding and model-based image reconstruction method.
Methods: By modeling the trajectories for every spoke and simplifying the scenario to only echo-in and echo-out mixture, the approach explicitly models the overlapping echoes. After modeling the overlapping echoes with two system matrices, we use the conjugate gradient algorithm (CG-SENSE) with the nonuniform FFT (NUFFT) to optimize the image reconstruction cost function.
Results: The proposed method is demonstrated in phantoms and in-vivo volunteer experiments for three-dimensional, high-resolution T2*-weighted imaging and functional MRI tasks. Compared to the gridding method, the high resolution protocol exhibits improved spatial resolution and reduced signal loss as a result of less intra-voxel dephasing. The fMRI task shows that the proposed model-based method produced images with reduced artifacts and blurring as well as more stable and prominent time courses.
Conclusion: The proposed model-based reconstruction results shows improved spatial resolution and reduced artifacts. The fMRI task shows improved time series and activation map due to the reduced overlapping echoes and under-sampling artifacts.
(© 2024 The Authors. Magnetic Resonance in Medicine published by Wiley Periodicals LLC on behalf of International Society for Magnetic Resonance in Medicine.)
Databáze: MEDLINE
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