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. 2021 Mar;85(3):1364-1378.
doi: 10.1002/mrm.28517. Epub 2020 Sep 29.

High-resolution multi-T1 -weighted contrast and T1 mapping with low B1>+ sensitivity using the fluid and white matter suppression (FLAWS) sequence at 7T

Jérémy Beaumont  1   2 , Giulio Gambarota  1 , Hervé Saint-Jalmes  1 , Oscar Acosta  1 , Jean-Christophe Ferré  3   4 , Parnesh Raniga  2 , Jurgen Fripp  2
Affiliations

High-resolution multi-T1 -weighted contrast and T1 mapping with low B1>+ sensitivity using the fluid and white matter suppression (FLAWS) sequence at 7T

Jérémy Beaumont et al. Magn Reson Med. 2021 Mar.

Abstract

Purpose: To demonstrate that fluid and white matter suppression (FLAWS) imaging can be used for high-resolution T1 mapping with low transmitted bias field ( B1+ ) sensitivity at 7T.

Methods: The FLAWS sequence was optimized for 0.8-mm isotropic resolution imaging. The theoretical accuracy and precision of the FLAWS T1 mapping was compared with the one of the magnetization-prepared two rapid gradient echoes (MP2RAGE) sequence optimized for low B1+ sensitivity. FLAWS images were acquired at 7T on six healthy volunteers (21 to 48 years old; two women). MP2RAGE and saturation-prepared with two rapid gradient echoes (SA2RAGE) datasets were also acquired to obtain T1 mapping references and B1+ maps. The contrast-to-noise ratio (CNR) between brain tissues was measured in the FLAWS-hco and MP2RAGE-uni images. The Pearson correlation was measured between the MP2RAGE and FLAWS T1 maps. The effect of B1+ on FLAWS T1 mapping was assessed using the Pearson correlation.

Results: The FLAWS-hco images were characterized by a higher brain tissue CNR ( CNRWM/GM=5.5 , CNRWM/CSF=14.7 , CNRGM/CSF=10.3 ) than the MP2RAGE-uni images ( CNRWM/GM=4.9 , CNRWM/CSF=6.6 , CNRGM/CSF=3.7 ). The theoretical accuracy and precision of the FLAWS T1 mapping ( acc=91.9%;prec=90.2% ) were in agreement with those provided by the MP2RAGE T1 mapping ( acc=90.0%;prec=86.8% ). A good agreement was found between in vivo T1 values measured with the MP2RAGE and FLAWS sequences (r = 0.91). A weak correlation was found between the FLAWS T1 map and the B1+ map within cortical gray matter and white matter segmentations ( rWM=-0.026 ; rGM=0.081 ).

Conclusion: The results from this study suggest that FLAWS is a good candidate for high-resolution T1 -weighted imaging and T1 mapping at the field strength of 7T.

Keywords: Brain; FLAWS; MP2RAGE; MRI; T1 mapping.

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References

REFERENCES

    1. Trattnig S, Springer E, Bogner W, et al. Key clinical benefits of neuroimaging at 7 T. Neuroimage. 2018;168:477-489.
    1. Marques JP, Kober T, Krueger G, van der Zwaag W, Van de Moortele P-F, Gruetter R. MP2RAGE, a self bias-field corrected sequence for improved segmentation and T1-mapping at high field. Neuroimage. 2010;49:1271-1281.
    1. Okubo G, Okada T, Yamamoto A, et al. MP2RAGE for deep gray matter measurement of the brain: A comparative study with MPRAGE. J Magn Reson Imaging. 2016;43:55-62.
    1. Kober T, Granziera C, Ribes D, et al. MP2RAGE multiple sclerosis magnetic resonance imaging at 3 T. Invest Radiol. 2012;47:346-352.
    1. Simioni S, Amarù F, Bonnier G, et al. MP2RAGE provides new clinically-compatible correlates of mild cognitive deficits in relapsing-remitting multiple sclerosis. J Neurol. 2014;261:1606-1613.

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