7 Tesla 22-channel wrap-around coil array for cervical spinal cord and brainstem imaging

Area of Science:

• Medical Imaging
• Biophysics
• Neuroscience

Background:

• Ultra-high field (7 Tesla) MRI offers superior signal-to-noise ratio and blood oxygenation level-dependent (BOLD) sensitivity.
• High-resolution imaging of the human cervical spinal cord and brainstem is challenging due to anatomical complexities.

Purpose of the Study:

• To develop and evaluate a novel two-panel radiofrequency (RF) coil array for improved 7T MRI of the human cervical spinal cord and brainstem.
• To leverage the benefits of ultra-high field MRI for detailed anatomical, functional, and diffusion imaging of these critical regions.

Main Methods:

• A two-panel RF coil array with 4 transmit/receive and 18 receive-only elements was designed and constructed.
• Simulations assessed B1+ field uniformity and specific absorption rate (SAR) compared to single-panel arrays.
• In vivo imaging performance (anatomical, functional, diffusion) was evaluated and compared to a posterior-only array.

Main Results:

• The two-panel array demonstrated more uniform B1+ distribution in the brainstem and cervical spinal cord without increased SAR.
• Receive sensitivity was 70% higher compared to a posterior-only array.
• The coil enabled accelerated imaging (2x2 or 3x acceleration) and acquisition of high-quality in vivo images.

Conclusions:

• A novel wrap-around, two-panel RF coil array provides excellent performance for 7T MRI of the cervical spinal cord and brainstem.
• This coil design facilitates simultaneous functional MRI of these regions.
• The developed coil effectively exploits the advantages of 7T MRI for high-resolution neuroimaging.