Non-water-suppressed short-echo-time magnetic resonance spectroscopic imaging using a concentric ring k-space trajectory
<p>Water-suppressed magnetic resonance spectroscopy (MRS) acquisition techniques have been the standard MRS approach used in research and for clinical scanning to date. The acquisition of a non-water-suppressed MRS spectrum is used for artefact correction, reconstruction of phased-array coil d...
| Main Authors: | , , , , |
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| Format: | Journal article |
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Wiley
2017
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| _version_ | 1797058659235135488 |
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| author | Emir, U Burns, B Chiew, M Jezzard, P Thomas, M |
| author_facet | Emir, U Burns, B Chiew, M Jezzard, P Thomas, M |
| author_sort | Emir, U |
| collection | OXFORD |
| description | <p>Water-suppressed magnetic resonance spectroscopy (MRS) acquisition techniques have been the standard MRS approach used in research and for clinical scanning to date. The acquisition of a non-water-suppressed MRS spectrum is used for artefact correction, reconstruction of phased-array coil data and metabolite quantification. Here, a two-scan metabolite-cycling spectroscopic imaging (MRSI) scheme is demonstrated and evaluated, that does not use water suppression. Specifically, the feasibility of acquiring and quantifying short-echo (TE = 14 ms), two-dimensional STEAM MRSI spectra in the motor cortex is demonstrated on a 3T MRI system. The increase in measurement time from the metabolite cycling is counterbalanced by a time-efficient concentric ring k-space trajectory. To validate the technique, water-suppressed MRSI acquisitions were also performed for comparison. The proposed non-water-suppressed metabolite-cycling MRSI technique was tested for detection and correction of resonance frequency drifts due to subject motion and/or hardware instability, and the feasibility of high-resolution metabolic mapping over a whole brain slice was assessed. Our results show that the metabolite spectra and estimated concentrations are in agreement between non-water-suppressed and water-suppressed techniques. The achieved spectral quality, signal-to-noise ratio > 20 and linewidth < 7 Hz allowed reliable metabolic mapping of five major brain metabolites in the motor cortex with an in-plane resolution of 10x10 mm2 in 8 minutes and with a Cramér-Rao lower bound of less than 20 % using LCModel analysis. In addition, the high SNR of the water peak of the non-water-suppressed technique enabled voxel-wise single-scan frequency, phase and eddy current correction. These findings demonstrate that our non-water-suppressed metabolite-cycling MRSI technique can perform robustly on 3T MRI systems and within a clinically feasible acquisition time.</p> |
| first_indexed | 2024-03-06T19:53:24Z |
| format | Journal article |
| id | oxford-uuid:24bbf68b-110c-4ecf-a9d9-277a6d2a1d94 |
| institution | University of Oxford |
| last_indexed | 2024-03-06T19:53:24Z |
| publishDate | 2017 |
| publisher | Wiley |
| record_format | dspace |
| spelling | oxford-uuid:24bbf68b-110c-4ecf-a9d9-277a6d2a1d942022-03-26T11:51:44ZNon-water-suppressed short-echo-time magnetic resonance spectroscopic imaging using a concentric ring k-space trajectoryJournal articlehttp://purl.org/coar/resource_type/c_dcae04bcuuid:24bbf68b-110c-4ecf-a9d9-277a6d2a1d94Symplectic Elements at OxfordWiley2017Emir, UBurns, BChiew, MJezzard, PThomas, M<p>Water-suppressed magnetic resonance spectroscopy (MRS) acquisition techniques have been the standard MRS approach used in research and for clinical scanning to date. The acquisition of a non-water-suppressed MRS spectrum is used for artefact correction, reconstruction of phased-array coil data and metabolite quantification. Here, a two-scan metabolite-cycling spectroscopic imaging (MRSI) scheme is demonstrated and evaluated, that does not use water suppression. Specifically, the feasibility of acquiring and quantifying short-echo (TE = 14 ms), two-dimensional STEAM MRSI spectra in the motor cortex is demonstrated on a 3T MRI system. The increase in measurement time from the metabolite cycling is counterbalanced by a time-efficient concentric ring k-space trajectory. To validate the technique, water-suppressed MRSI acquisitions were also performed for comparison. The proposed non-water-suppressed metabolite-cycling MRSI technique was tested for detection and correction of resonance frequency drifts due to subject motion and/or hardware instability, and the feasibility of high-resolution metabolic mapping over a whole brain slice was assessed. Our results show that the metabolite spectra and estimated concentrations are in agreement between non-water-suppressed and water-suppressed techniques. The achieved spectral quality, signal-to-noise ratio > 20 and linewidth < 7 Hz allowed reliable metabolic mapping of five major brain metabolites in the motor cortex with an in-plane resolution of 10x10 mm2 in 8 minutes and with a Cramér-Rao lower bound of less than 20 % using LCModel analysis. In addition, the high SNR of the water peak of the non-water-suppressed technique enabled voxel-wise single-scan frequency, phase and eddy current correction. These findings demonstrate that our non-water-suppressed metabolite-cycling MRSI technique can perform robustly on 3T MRI systems and within a clinically feasible acquisition time.</p> |
| spellingShingle | Emir, U Burns, B Chiew, M Jezzard, P Thomas, M Non-water-suppressed short-echo-time magnetic resonance spectroscopic imaging using a concentric ring k-space trajectory |
| title | Non-water-suppressed short-echo-time magnetic resonance spectroscopic imaging using a concentric ring k-space trajectory |
| title_full | Non-water-suppressed short-echo-time magnetic resonance spectroscopic imaging using a concentric ring k-space trajectory |
| title_fullStr | Non-water-suppressed short-echo-time magnetic resonance spectroscopic imaging using a concentric ring k-space trajectory |
| title_full_unstemmed | Non-water-suppressed short-echo-time magnetic resonance spectroscopic imaging using a concentric ring k-space trajectory |
| title_short | Non-water-suppressed short-echo-time magnetic resonance spectroscopic imaging using a concentric ring k-space trajectory |
| title_sort | non water suppressed short echo time magnetic resonance spectroscopic imaging using a concentric ring k space trajectory |
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