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Updated: Jan 27, 2026
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fMRI Validation of fNIRS Measurements During a Naturalistic Task
Published on: June 15, 2015
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Optimizing BOLD sensitivity in the 7T Human Connectome Project resting-state fMRI protocol using plug-and-play
Vincent Gras1, Benedikt A Poser2, Xiaoping Wu3
1NeuroSpin, CEA, University of Paris-Saclay, Gif-sur-Yvette, France.
Neuroimage
|March 30, 2019
Summary
This study introduces parallel transmission Universal Pulses for 7T MRI, improving brain scan homogeneity. This technique enhances signal quality and functional connectivity detection, overcoming radiofrequency field limitations.
Area of Science:
- Neuroimaging
- Magnetic Resonance Imaging (MRI)
- Human Connectome Project (HCP)
Background:
- 7T MRI offers high spatial and temporal resolution for brain studies.
- Radiofrequency transmission field (B1+) heterogeneity is a key limitation at 7T.
- This inhomogeneity affects signal and contrast, hindering whole-brain analysis.
Purpose of the Study:
- To improve B1+ homogeneity at 7T using parallel transmission (pTX) Universal Pulses (UPs).
- To demonstrate the application of pTX UPs in accelerated multi-band EPI and anatomical scans for the HCP protocol.
- To achieve operator-independent, plug-and-play implementation of pTX benefits.
Main Methods:
- Implementation of pTX Universal Pulses for 7T MRI.
- Application to multi-band EPI (MB5, GRAPPA2) and T1/T2-weighted anatomical scans.
- Validation in five healthy adult participants.
Main Results:
- Achieved flip angle homogeneity comparable to 3T systems.
- Demonstrated B1+-artifact-free anatomical scans.
- UPs at 7T doubled temporal signal-to-noise ratio in temporal lobes.
- Improved functional connectivity detection in B1+-affected regions.
Conclusions:
- pTX UPs effectively address B1+ heterogeneity at 7T.
- The proposed method enhances image quality and functional connectivity analysis for HCP.
- This operator-independent solution facilitates widespread adoption of advanced 7T MRI techniques.
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