A Birdcage Volume Transmit Coil and 8 Channel Receive Array for Marmoset Brain Imaging at 7T.

Area of Science:

• * Neuroimaging
• * Primate models
• * Magnetic Resonance Imaging (MRI)

Background:

• * High-field MRI at 7 Tesla (7T) offers enhanced signal-to-noise ratio (SNR) and spatial resolution.
• * Marmoset models are crucial for studying primate brain development and function.
• * Specialized radiofrequency (RF) coils are necessary for optimal imaging in small animal models at ultra-high fields.

Purpose of the Study:

• * To design and fabricate a specialized MRI coil system for marmoset brain imaging at 7T.
• * To enable high-resolution imaging of both awake and anesthetized marmosets.
• * To ensure compatibility with a whole-body 7T clinical MRI scanner.

Main Methods:

• * Fabrication of a shielded, band-pass birdcage transmit coil with 24 legs.
• * Development of an 8-channel, conformal receive array coil with overlapped loop elements.
• * Electromagnetic (EM) field simulations for B1+ efficiency and performance evaluation using phantoms and in vivo imaging.

Main Results:

• * Achieved high-resolution marmoset brain images (0.8 mm isotropic for EPI, 0.36 mm isotropic for structural).
• * Obtained high SNR (50-80) in both anesthetized and awake marmoset brain scans.
• * Simulated B1+ efficiency of the birdcage coil was 2.6 µT/sqrt(W) at the phantom center.

Conclusions:

• * A functional 7T MRI coil system for marmoset brain imaging was successfully designed and fabricated.
• * The coil system supports imaging of both young and older marmosets, suitable for longitudinal studies.
• * This coil facilitates research into primate neurodevelopment and brain function.