Perfusion-based high-resolution functional imaging in the human brain at 7 Tesla.

Area of Science:

• Neuroimaging
• Magnetic Resonance Imaging (MRI)
• Human Brain Physiology

Background:

• Perfusion MRI measures cerebral blood flow (CBF) at the capillary level, crucial for functional brain studies due to the link between neural activity and blood flow.
• Achieving high spatial resolution in functional CBF mapping is challenging due to low signal-to-noise ratio (SNR).

Purpose of the Study:

• To develop and validate high-resolution CBF-based functional imaging in the human brain.
• To compare the performance of high-resolution CBF imaging with functional Blood-Oxygen-Level-Dependent (BOLD) imaging.

Main Methods:

• Utilized a 7 Tesla (T) MRI scanner with a novel RF combination coil design to enhance signal-to-noise ratio (SNR).
• Employed a reduced field-of-view and gradient-echo echo-planar imaging in a single shot to achieve small voxel sizes (0.9 x 0.9 x 1.5 mm³).
• Acquired and compared functional CBF and BOLD data.

Main Results:

• Successfully obtained high-resolution CBF maps with voxel sizes as small as 0.9 x 0.9 x 1.5 mm³ in the human brain.
• Demonstrated significant contrast-to-noise gains for CBF at high spatial resolution compared to BOLD.
• Observed that functional CBF responses were more localized than BOLD responses at high resolution.

Conclusions:

• High-resolution functional CBF imaging at 7 T provides superior localization and specificity for monitoring brain function.
• This advanced technique offers valuable insights for neuroscience research, surpassing conventional BOLD imaging in certain aspects.