Ultra-high field birdcage coils: a comparison study at 14.1T

Area of Science:

• Magnetic Resonance Imaging (MRI)
• Biophysics
• Coil Engineering

Background:

• Uniform B(1)(+) excitation is crucial for magnetic resonance (MR) probes in imaging and spectroscopy.
• Higher magnetic field strengths increase constraints on MR probe size, sample size, and radiation losses.

Purpose of the Study:

• To simulate, test, and construct birdcage coils for rodent imaging at 14.1 T.
• To investigate the factors causing B(1)(+) field inhomogeneity at high magnetic fields.

Main Methods:

• Birdcage coil design and simulation for 14.1 T operation.
• Bench experiments to evaluate coil performance.
• In vivo imaging tests on rodent brains.

Main Results:

• Two birdcage coils were successfully constructed and tested for 14.1 T rodent imaging.
• Dielectric resonance was identified as the primary cause of B(1)(+) field inhomogeneity at 14.1 T.
• Despite inhomogeneity, the coils enabled achievable imaging of rodent brains.

Conclusions:

• Birdcage coil performance at 14.1 T is significantly influenced by dielectric resonance.
• Effective rodent brain imaging is feasible at 14.1 T using optimized birdcage coils.
• This work contributes to advancements in high-field small-animal MRI.