Closely-spaced double-row microstrip RF arrays for parallel MR imaging at ultrahigh fields

Area of Science:

• Magnetic Resonance Imaging (MRI)
• RF Engineering
• Coil Array Design

Background:

• High-element-count RF coil arrays enhance parallel imaging in MRI.
• Building closely-spaced multi-row arrays is complex due to element coupling.

Purpose of the Study:

• To present a novel and simple method for designing closely-spaced multi-row RF coil arrays.
• To investigate and validate the Induced Current Elimination (ICE) decoupling method for same-row element isolation.
• To demonstrate the performance of a 16-channel, closely-spaced double-row microstrip array at 7T.

Main Methods:

• Utilized the Induced Current Elimination (ICE) decoupling technique.
• Investigated ICE for same-row decoupling via bench tests, achieving isolation improvement from -8.9 dB to -20.7 dB.
• Fabricated a 16-element, closely-spaced double-row microstrip array for 7T MRI and performed MRI experiments.

Main Results:

• Achieved isolation better than -14 dB between any two elements in the 16-channel array.
• Demonstrated no significant noise amplification in parallel imaging with a reduction factor (R) of 4.
• Validated the feasibility and performance of the proposed array design through MRI experiments.

Conclusions:

• The proposed Induced Current Elimination (ICE) method offers a simple and efficient approach for fabricating closely-spaced multi-row RF coil arrays.
• This design facilitates superior parallel imaging performance in high-field MRI (7T).
• The method addresses the technical challenges associated with building complex RF coil arrays.