7T transmit/receive arrays using ICE decoupling for human head MR imaging.

Area of Science:

• Magnetic Resonance Imaging (MRI)
• Radiofrequency (RF) Engineering
• Biomedical Engineering

Background:

• Designing large volume phased array coils for 7 Tesla (7T) human head MRI presents challenges in minimizing electromagnetic coupling between elements.
• Existing decoupling methods may limit performance in ultrahigh field applications.

Purpose of the Study:

• To build and evaluate an eight-channel transmit/receive volume array using the Induced Current Compensation or Elimination (ICE) decoupling technique for 7T human head imaging.
• To demonstrate the feasibility and robustness of ICE decoupling for high-performance MRI.

Main Methods:

• An eight-channel volume array with ICE-decoupled loop elements was constructed.
• Electromagnetic isolation was measured with and without a human head load.
• MRI experiments were conducted on a 7T scanner using phantoms and human subjects.
• Image quality and parallel imaging performance were assessed using g-factor maps and signal-to-noise ratio (SNR) measurements.

Main Results:

• The ICE-decoupled array achieved isolation better than -25 dB between adjacent elements and -17.5 dB worst-case isolation with a human head load.
• Compared to conventional capacitively decoupled arrays, the ICE-decoupled array showed improved parallel imaging performance.
• Higher SNR was observed with the ICE-decoupled array.

Conclusions:

• The ICE decoupling technique is effective in reducing electromagnetic coupling in 7T volume transmit/receive arrays.
• This approach offers improved parallel imaging capabilities and higher SNR for human head imaging at ultrahigh fields.
• The ICE-decoupled transceiver array design is a promising solution for high-performance ultrahigh field MRI.