A 16-channel loop array for in vivo macaque whole-brain imaging at 7 T

Area of Science:

• Neuroimaging
• Biomedical Engineering
• Primate Neuroscience

Background:

• Multimodal approaches combined with functional magnetic resonance imaging (fMRI) are advancing non-human primate (NHP) brain circuitry research.
• A significant limitation in current NHP neuroimaging studies is the scarcity of suitable radiofrequency (RF) coils.
• High-field MRI (7 Tesla) offers enhanced resolution but requires optimized RF coil technology for NHP applications.

Purpose of the Study:

• To design and construct a specialized 16-channel receive array RF coil for macaque brain imaging at 7 Tesla.
• To evaluate the performance of the custom-built coil against a commercial coil for macaque brain imaging.
• To assess the coil's suitability for multimodal imaging and detailed investigation of brain circuitries.

Main Methods:

• Construction of a 16-channel receive array RF coil integrated with a single loop transmit coil on a 3D-printed helmet.
• The coil design incorporates openings for multimodal devices around cortical regions for simultaneous imaging and stimulation/recording.
• Coil performance evaluation using quantitative metrics including signal-to-noise ratio (SNR), noise correlations, g-factor, and flip-angle maps in vivo.
• Comparison of the custom macaque coil's performance against a 28-channel commercial knee coil.

Main Results:

• The custom-built 16-channel macaque RF coil demonstrated superior SNR in cortical regions compared to the commercial knee coil.
• The coil exhibited enhanced acceleration capabilities in parallel imaging, crucial for reducing scan times and improving spatial resolution.
• In vivo imaging results validated the coil's effectiveness for high-resolution macaque brain studies.

Conclusions:

• The developed 16-channel RF coil is highly effective for high-field (7T) macaque brain imaging.
• The coil's design facilitates multimodal approaches and offers improved SNR and parallel imaging performance.
• This technology advancement is expected to significantly benefit research into mesoscale brain organizations in non-human primates.