128-channel body MRI with a flexible high-density receiver-coil array

Area of Science:

• Medical Imaging
• Biophysics

Background:

• Parallel imaging in MRI accelerates data acquisition by undersampling k-space.
• High-density receiver arrays are theorized to improve parallel imaging performance.
• Previous systems had limitations in coil density and acceleration factors.

Purpose of the Study:

• To validate the practical feasibility of high-density, many-coil MRI receiver arrays for accelerated parallel imaging.
• To assess the performance gains in signal-to-noise ratio (SNR) and acceleration capabilities.

Main Methods:

• Development of a custom 128-channel body receiver-coil array and MRI system.
• Phantom and human body imaging using various acceleration factors (reduction factors) and pulse sequences (2D/3D).
• Comparison of the 128-channel array against a 32-channel array of similar footprint.

Main Results:

• The 128-channel array demonstrated improved SNR (1.03x center, 1.7x average outer regions) compared to a 32-channel array.
• Maximum g-factors significantly decreased from 5.5 to 2.0 (4x4 acceleration) and 25 to 3.3 (5x5 acceleration).
• Reduced aliasing artifacts were observed in human body imaging with an 8x acceleration factor.

Conclusions:

• MRI utilizing a large number of receiver channels enables substantially higher parallel imaging acceleration factors.
• Improved SNR is achievable with high-channel-count arrays, contingent on minimizing coil and electronic losses.
• The practical realization of accelerated parallel imaging with high-density arrays is confirmed.