Skip to main page content
U.S. flag

An official website of the United States government

Dot gov

The .gov means it’s official.
Federal government websites often end in .gov or .mil. Before sharing sensitive information, make sure you’re on a federal government site.

Https

The site is secure.
The https:// ensures that you are connecting to the official website and that any information you provide is encrypted and transmitted securely.

Access keys NCBI Homepage MyNCBI Homepage Main Content Main Navigation
. 2020 Sep;84(3):1441-1455.
doi: 10.1002/mrm.28222. Epub 2020 Feb 28.

Optimizing 3D EPI for rapid T1 -weighted imaging

Ola Norbeck  1   2 , Tim Sprenger  3 , Enrico Avventi  1   2 , Henric Rydén  1   2 , Annika Kits  1   2 , Johan Berglund  2 , Stefan Skare  1   2
Affiliations
Free article

Optimizing 3D EPI for rapid T1 -weighted imaging

Ola Norbeck et al. Magn Reson Med. 2020 Sep.
Free article

Abstract

Purpose: To investigate the use of 3D EPI for rapid T1 -weighted brain imaging, focusing on the RF pulse's influence on the contrast between gray and white matter.

Methods: An interleaved 3D EPI sequence use partial Fourier and CAIPIRINHA sampling was used to acquire T1 -weighted brain volumes with isotropic resolution, low echo times, and low geometric distortions. Five different RF pulses were evaluated in terms of fat suppression performance and gray-white matter contrast. Two binomial RF pulses were compared to a single rectangular (WE-rect) RF pulse exciting only water, and two new RF pulses developed in this work, where one was an extension of the WE-rect, and the other was an SLR pulse. The technique was demonstrated in three clinical cases, where brain tumor patients were imaged before and after gadolinium administration.

Results: A fat-suppressed 3D EPI sequence with a phase encoding bandwidth of around 100 Hz was found to exhibit a good trade-off between geometrical distortions and scan duration. Whole-brain T1 -weighted 3D EPI images with 1.2 mm isotropic voxel size could be acquired in 24 seconds. The WE-rect, its extension, and the SLR RF pulses resulted in reduced magnetization transfer effects and provided a 20% mean increase in gray-white matter contrast.

Conclusion: Using a high phase encoding bandwidth and RF pulses that reduce magnetization transfer effects, a fat-suppressed multi-shot 3D EPI sequence can be used to rapidly acquire isotropic T1 -weighted volumes.

Keywords: 3D; EPI; RF; T1-weighted; binomial; brain.

PubMed Disclaimer

References

    1. Mansfield P. Multi-planar image formation using NMR spin echoes. J Phys C: Solid State Phys. 1977;10:L55-L58.
    1. Belliveau J, Kennedy D, McKinstry R, et al. Functional mapping of the human visual cortex by magnetic resonance imaging. Science. 1991;254:716-719.
    1. Edelman RR, Siewert B, Darby DG, et al. Qualitative mapping of cerebral blood flow and functional localization with echo-planar MR imaging and signal targeting with alternating radio frequency. Radiology. 1994;192:513-520.
    1. Turner R, Le Bihan D, Maier J, Vavrek R, Hedges LK, Pekar J. Echo-planar imaging of intravoxel incoherent motion. Radiology. 1990;177:407-414.
    1. Skare S, Sprenger T, Norbeck O, et al. A 1-minute full brain MR exam using a multicontrast EPI sequence. Magn Reson Med. 2018;79:3045-3054.

Publication types

LinkOut - more resources