Pushing spatial and temporal resolution for functional and diffusion MRI in the Human Connectome Project.

Area of Science:

• Neuroimaging
• Human Brain Mapping
• Magnetic Resonance Imaging

Background:

• The Human Connectome Project (HCP) utilizes complementary magnetic resonance (MR) methods to study brain structure and function.
• Key methods include resting-state functional MR imaging (rfMRI), diffusion imaging (dMRI), and task-based fMRI (tfMRI).

Purpose of the Study:

• To describe technical improvements and optimizations for MR imaging methods used in the HCP.
• To enhance the speed and resolution of fMRI and dMRI data acquisition at 3T and 7T.
• To advance the investigation of human brain function and structure.

Main Methods:

• Optimized acquisition protocols for resting-state fMRI (rfMRI) and diffusion MRI (dMRI) at 3T.
• Achieved whole-brain coverage with 2 mm isotropic resolution in 0.7s for rfMRI.
• Reduced dMRI acquisition time by threefold while maintaining 1.25 mm isotropic resolution for tractography.

Main Results:

• Demonstrated significant advances in MR imaging for human brain analysis.
• Presented ongoing developments for 7T MRI, targeting higher spatial resolution and signal specificity.
• Highlighted mitigation strategies for radiofrequency (RF) field inhomogeneity and power deposition at 7T.

Conclusions:

• Optimized MR imaging techniques significantly advance the study of human brain function and structure.
• Technical improvements enhance data acquisition speed and resolution for both 3T and 7T systems.
• These advancements provide powerful tools for detailed connectome research.