An orthogonal-based decoupling method for MRI phased array coil design

Area of Science:

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

Background:

• Mutual coupling between coil elements is a significant challenge in radiofrequency (RF) coil array design.
• Existing methods for mitigating mutual coupling often rely on passive decoupling schemes, which can add complexity and reduce efficiency.
• Optimizing RF coil performance is crucial for enhancing image quality and enabling advanced applications in magnetic resonance imaging.

Purpose of the Study:

• To design and construct a novel 3-element orthogonal knee coil array.
• To minimize mutual coupling effects without using passive decoupling methods.
• To evaluate the performance and flexibility of the new coil array for magnetic resonance imaging applications.

Main Methods:

• The study employed the three-dimensional orthogonality principle to design a 3-element orthogonal knee coil array.
• The coil array was constructed and tested using a standardized phantom, human knees, and pig knees.
• Experimental assessments involved angling the coil array relative to the main static magnetic field (B(0)) and evaluating signal intensity in specific anatomical structures.

Main Results:

• The 3-element orthogonal knee coil array successfully minimized mutual coupling effects.
• The coil array maintained normal operation and efficiency when angled arbitrarily, including at 90°, relative to B(0).
• Maximum signal intensity in the patellar ligament of a pig knee was observed at a ~55° angle to B(0), suggesting potential for magic angle MR applications.

Conclusions:

• The proposed orthogonal coil design is effective in reducing mutual coupling for RF coil arrays.
• This innovative coil array offers flexibility in positioning for various MRI and spectroscopic studies in humans and animals.
• The findings indicate potential applications in advanced MR techniques, such as magic angle imaging, for detailed tissue analysis.