A 128-channel receive array for cortical brain imaging at 7 T.

Area of Science:

• Medical Imaging
• Neuroimaging
• Radiofrequency Coil Technology

Background:

• High-field MRI (7 Tesla) offers enhanced signal but faces challenges with coil sensitivity and noise.
• Developing advanced radiofrequency (RF) coils is crucial for maximizing the benefits of ultra-high field MRI.

Purpose of the Study:

• To simulate, design, construct, and evaluate a 128-channel receive-only RF array for 7T brain imaging.
• To assess the signal-to-noise ratio (SNR) and parallel imaging performance of the 128-channel array.

Main Methods:

• A 128-channel receive-only array with a tight-fitting helmet geometry was designed and built.
• Electromagnetic modeling was used for simulations.
• In vivo SNR and parallel imaging (1/g factor) performance were measured and compared to 32- and 64-channel arrays.

Main Results:

• The 128-channel array demonstrated improved intrinsic SNR and g-factor performance.
• Significant SNR gains were observed in both central (17.6-42%) and peripheral (42-86.7%) brain regions compared to lower-channel arrays.
• Parallel imaging acceleration showed more pronounced benefits with increased channel count.

Conclusions:

• Increasing RF coil channel count to 128 is beneficial for 7T brain imaging.
• The 128-channel array enhances SNR in peripheral regions and improves accelerated imaging capabilities.
• This technology advances high-resolution functional neuroimaging at ultra-high fields.