Pushing MP2RAGE boundaries: Ultimate time-efficient parameterization combined with exhaustive T 1 synthetic contrasts.

Autor: Bapst B; University of Paris-Saclay, CEA, CNRS, BAOBAB, NeuroSpin, Gif-sur-Yvette, France.; Department of Neuroradiology, AP-HP, Henri Mondor University Hospital, Créteil, France.; EA 4391, Université Paris Est Créteil, Créteil, France., Massire A; Siemens Healthcare SAS, Courbevoie, France., Mauconduit F; University of Paris-Saclay, CEA, CNRS, BAOBAB, NeuroSpin, Gif-sur-Yvette, France., Gras V; University of Paris-Saclay, CEA, CNRS, BAOBAB, NeuroSpin, Gif-sur-Yvette, France., Boulant N; University of Paris-Saclay, CEA, CNRS, BAOBAB, NeuroSpin, Gif-sur-Yvette, France., Dufour J; Sorbonne Université, Paris Brain Institute, ICM, CNRS, Inserm, Paris, France., Bodini B; Sorbonne Université, Paris Brain Institute, ICM, CNRS, Inserm, Paris, France., Stankoff B; Sorbonne Université, Paris Brain Institute, ICM, CNRS, Inserm, Paris, France., Luciani A; Department of Medical Imaging, Henri Mondor University Hospital, Créteil, France., Vignaud A; University of Paris-Saclay, CEA, CNRS, BAOBAB, NeuroSpin, Gif-sur-Yvette, France.
Jazyk: angličtina
Zdroj: Magnetic resonance in medicine [Magn Reson Med] 2024 Apr; Vol. 91 (4), pp. 1608-1624. Date of Electronic Publication: 2023 Dec 15.
DOI: 10.1002/mrm.29948
Abstrakt: Purpose: MP2RAGE parameter optimization is redefined to allow more time-efficient MR acquisitions, whereas the T 1 -based synthetic imaging framework is used to obtain on-demand T 1 -weighted contrasts. Our aim was to validate this concept on healthy volunteers and patients with multiple sclerosis, using plug-and-play parallel-transmission brain imaging at 7 T.
Methods: A "time-efficient" MP2RAGE sequence was designed with optimized parameters including TI and TR set as small as possible. Extended phase graph formalism was used to set flip-angle values to maximize the gray-to-white-matter contrast-to-noise ratio (CNR). Several synthetic contrasts (UNI, EDGE, FGATIR, FLAWS MIN , FLAWS HCO ) were generated online based on the acquired T 1 maps. Experimental validation was performed on 4 healthy volunteers at various spatial resolutions. Clinical applicability was evaluated on 6 patients with multiple sclerosis, scanned with both time-efficient and conventional MP2RAGE parameterizations.
Results: The proposed time-efficient MP2RAGE protocols reduced acquisition time by 40%, 30%, and 19% for brain imaging at (1 mm) 3 , (0.80 mm) 3 and (0.65 mm) 3 , respectively, when compared with conventional parameterizations. They also provided all synthetic contrasts and comparable contrast-to-noise ratio on UNI images. The flexibility in parameter selection allowed us to obtain a whole-brain (0.45 mm) 3 acquisition in 19 min 56 s. On patients with multiple sclerosis, a (0.67 mm) 3 time-efficient acquisition enhanced cortical lesion visualization compared with a conventional (0.80 mm) 3 protocol, while decreasing the scan time by 15%.
Conclusion: The proposed optimization, associated with T 1 -based synthetic contrasts, enabled substantial decrease of the acquisition time or higher spatial resolution scans for a given time budget, while generating all typical brain contrasts derived from MP2RAGE.
(© 2023 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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