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Whole-brain 3D FLAIR at 7T using direct signal control
Arian Beqiri1, Hans Hoogduin2, Alessandro Sbrizzi2
1Department of Biomedical Engineering, School of Biomedical Engineering & Imaging Sciences, King's College London, King's Health Partners, St Thomas' Hospital, London, United Kingdom.
Magnetic Resonance in Medicine
|February 25, 2018
Summary
Direct Signal Control (DSC) improves 7T 3D FLAIR brain imaging by correcting signal inhomogeneities. This method ensures whole-brain coverage without dropout, enhancing diagnostic efficacy for neurological disorders.
Area of Science:
- Magnetic Resonance Imaging
- Neuroimaging
- Biomedical Engineering
Background:
- 7T MRI offers high resolution but suffers from static magnetic field (B0) and RF field (B1) inhomogeneities.
- These inhomogeneities cause signal variations in 3D FLAIR sequences, reducing clinical efficacy for neurological disorder assessment.
Purpose of the Study:
- To correct signal inhomogeneities in 7T 3D FLAIR brain imaging.
- To ensure consistent whole-brain coverage and improve diagnostic accuracy.
Main Methods:
- The Direct Signal Control (DSC) framework was employed to optimize transmit channel weightings pulse-by-pulse.
- 3D FLAIR brain images were acquired on 5 subjects, comparing DSC with quadrature mode.
- Precomputed universal DSC solutions were also evaluated.
Main Results:
- DSC consistently improved 7T 3D FLAIR imaging across all subjects, eliminating signal dropouts.
- Imaging in quadrature mode showed significant signal dropouts.
- Universal DSC solutions also improved imaging performance without subject-specific optimization.
Conclusions:
- Direct Signal Control (DSC) substantially enhances 7T 3D FLAIR brain imaging quality.
- DSC recovers low-signal regions effectively without increasing scan time or interecho spacing.
- This technique improves diagnostic potential for neurological conditions using high-field MRI.
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