Researchers at Colorado State University have developed a new radiofrequency (RF) coil for MRI scanners using a multi-channel helical (spiral) antenna design. The technology produces a more uniform and circularly polarized magnetic field, especially at higher magnetic strengths. It supports advanced multi-channel transmission methods used in next-generation MRI systems. The design also expands the imaging field of view and improves overall signal quality.
MRI image quality improves as magnetic field strength increases, but higher-field systems (>3 T) introduce challenges in maintaining uniform RF magnetic fields. Conventional RF coil designs, such as birdcage coils, perform well at lower field strengths but struggle to provide consistent field distribution at higher strengths. This leads to uneven image quality and reduced reliability. As MRI technology advances toward ultra-high-field systems, new RF coil architectures are required to maintain performance and unlock the full potential of these scanners.
This technology introduces a helical antenna-based RF coil that uses multiple channels (typically 4 or 8) to generate and control the RF magnetic field in MRI systems. The spiral geometry enables improved circular polarization and more uniform field distribution compared to traditional coil designs. The approach also supports RF shimming and parallel transmission, allowing better control over field behavior within the imaging region.
Prototypes of the helical coil have been built and tested in ultra-high-field MRI systems operating at 7 T and 10.5 T. Experimental results closely match simulation predictions, confirming the design’s reliability. Compared to standard birdcage coils and patch antenna approaches, this design offers improved field uniformity, stronger signal penetration, and a larger usable imaging region. Importantly, the concept is not limited to a specific field strength or frequency, making it adaptable for current and future MRI platforms above 3 T.
Available for Licensing
TRL: 3
Branislav M. Notaroš
Milan M. Ilić
Alexey Tonyushkin
Nada J. Šekeljić
Pranav Athalye
Aly Hoeher
Aly.Hoeher@colostate.edu
970-491-7100