Simulation verification of SNR and parallel imaging improvements by ICE-decoupled loop array in MRI

Area of Science:

• Magnetic Resonance Imaging (MRI)
• Electromagnetics
• RF Engineering

Background:

• Transmit/receive L/C loop arrays are crucial for ultrahigh field MRI (e.g., 7 T).
• Induced Current Elimination (ICE) and magnetic wall decoupling methods offer high signal-to-noise ratio (SNR) and parallel imaging capabilities.
• Optimizing coil performance is essential for advanced MRI applications.

Purpose of the Study:

• To numerically analyze the performance of an eight-channel ICE-decoupled loop array at 7 T.
• To evaluate the effectiveness of the ICE method in improving MRI coil performance.
• To compare the ICE-decoupled array with conventional capacitively decoupled arrays.

Main Methods:

• A three-dimensional (3-D) electromagnetic (EM) and radiofrequency (RF) circuit co-simulation approach was utilized.
• Capacitor values were optimized by analyzing S-parameters for all coil elements.
• EM simulation accurately modeled the coil structure, phantom, and excitation.

Main Results:

• All coil elements achieved excellent matching to 50 ohms with isolation better than -15 dB.
• Simulated S-parameters closely matched experimental results, validating the simulation's reliability.
• The ICE-decoupled array demonstrated higher sensitivity in peripheral areas compared to conventional arrays.

Conclusions:

• The ICE-decoupled loop array offers superior performance at ultrahigh fields.
• The shielding effect of decoupling loops enhances peripheral sensitivity and SNR.
• Numerical simulations accurately predict the performance of ICE-decoupled arrays, validating their use in advanced MRI.