biostudies-literatureGuo RNIBIB NIH HHSFoundation for the National Institutes of Health970-977https://www.ebi.ac.uk/biostudies/studies/S-EPMC7722130biostudies-literatureUnknown85(2)<h4>Purpose</h4>To achieve high-resolution mapping of brain tissue susceptibility in simultaneous QSM and metabolic imaging.<h4>Methods</h4>Simultaneous QSM and metabolic imaging was first achieved using SPICE (spectroscopic imaging by exploiting spatiospectral correlation), but the QSM maps thus obtained were at relatively low-resolution (2.0 × 3.0 × 3.0 mm³ ). We overcome this limitation using an improved SPICE data acquisition method with the following novel features: 1) sampling (k, t)-space in dual densities, 2) sampling central k-space fully to achieve nominal spatial resolution of 3.0 × 3.0 × 3.0 mm³ for metabolic imaging, and 3) sampling outer k-space sparsely to achieve spatial resolution of 1.0 × 1.0 × 1.9 mm³ for QSM. To keep the scan time short, we acquired spatiospectral encodings in echo-planar spectroscopic imaging trajectories in central k-space but in CAIPIRINHA (controlled aliasing in parallel imaging results in higher acceleration) trajectories in outer k-space using blipped phase encodings. For data processing and image reconstruction, a union-of-subspaces model was used, effectively incorporating sensitivity encoding, spatial priors, and spectral priors of individual molecules.<h4>Results</h4>In vivo experiments were carried out to evaluate the feasibility and potential of the proposed method. In a 6-min scan, QSM maps at 1.0 × 1.0 × 1.9 mm³ resolution and metabolic maps at 3.0 × 3.0 × 3.0 mm³ nominal resolution were obtained simultaneously. Compared with the original method, the QSM maps obtained using the new method reveal fine-scale brain structures more clearly.<h4>Conclusion</h4>We demonstrated the feasibility of achieving high-resolution QSM simultaneously with metabolic imaging using a modified SPICE acquisition method. The improved capability of SPICE may further enhance its practical utility in brain mapping.Magnetic resonance in medicineSimultaneous QSM and metabolic imaging of the brain using SPICE: Further improvements in data acquisition and processing.PMC7722130U01 EB026978NIH‐U01‐EB026978R21 EB023413NIH‐R21‐EB023413Sutton BLi YLiang ZPWang TGuo RZhao YfalseSimultaneous QSM and metabolic imaging of the brain using SPICE: Further improvements in data acquisition and processing.<h4>Purpose</h4>To achieve high-resolution mapping of brain tissue susceptibility in simultaneous QSM and metabolic imaging.<h4>Methods</h4>Simultaneous QSM and metabolic imaging was first achieved using SPICE (spectroscopic imaging by exploiting spatiospectral correlation), but the QSM maps thus obtained were at relatively low-resolution (2.0 × 3.0 × 3.0 mm³ ). We overcome this limitation using an improved SPICE data acquisition method with the following novel features: 1) sampling (k, t)-space in dual densities, 2) sampling central k-space fully to achieve nominal spatial resolution of 3.0 × 3.0 × 3.0 mm³ for metabolic imaging, and 3) sampling outer k-space sparsely to achieve spatial resolution of 1.0 × 1.0 × 1.9 mm³ for QSM. To keep the scan time short, we acquired spatiospectral encodings in echo-planar spectroscopic imaging trajectories in central k-space but in CAIPIRINHA (controlled aliasing in parallel imaging results in higher acceleration) trajectories in outer k-space using blipped phase encodings. For data processing and image reconstruction, a union-of-subspaces model was used, effectively incorporating sensitivity encoding, spatial priors, and spectral priors of individual molecules.<h4>Results</h4>In vivo experiments were carried out to evaluate the feasibility and potential of the proposed method. In a 6-min scan, QSM maps at 1.0 × 1.0 × 1.9 mm³ resolution and metabolic maps at 3.0 × 3.0 × 3.0 mm³ nominal resolution were obtained simultaneously. Compared with the original method, the QSM maps obtained using the new method reveal fine-scale brain structures more clearly.<h4>Conclusion</h4>We demonstrated the feasibility of achieving high-resolution QSM simultaneously with metabolic imaging using a modified SPICE acquisition method. The improved capability of SPICE may further enhance its practical utility in brain mapping.2021-01-01T00:00:00Z2021 Feb2024-10-19T04:44:55.943Z2022-02-11T15:55:52.115ZS-EPMC77221303281031910.1002/mrm.28459