Numerical Analysis of the Comprehensive Performance of Straight Dipole Arrays for 11.74 T MRI Brain Imaging

The use of ultra-high magnetic fields, such as 11.74 T in magnetic resonance imaging (MRI), offers great potential for achieving superior image quality and enabling advanced imaging applications. The development of new field-strength systems requires an investigation into the performance of radiofrequency transmitters and receivers. Loop coils are a popular choice for MRI scanners up to 7 T, with better performance exhibited at 3 T, whereas volume coils such as birdcage coils are preferred for 1.5 T scanners. On this basis, the field strength of 11.74 T raises the question of which resonator design will provide superior performance. Dipole antennas have been proposed for many applications involving different field strengths and target organs. One of the limitations of dipole antennas is the relationship between the resonance and the length. At 11.74 T, the dipole frequency of operation is 500 MHz, which provides a dipole antenna length of approximately 28 cm, which is acceptable for an MRI scanner. This study analyzed the transmission and reception performances of dipole arrays with different radii in terms of field intensity, uniformity, SAR, effectiveness, g-factor, and field optimization.