AUTHORS: Wenz D, Xin L, Dardano T, Kuehne A

Magnetic Resonance in Medicine, : , June 2023

ABSTRACT

Purpose

To introduce the dipolectric antenna: a novel RF coil design for high-field MRI using a combination of a dipole antenna with a loop-coupled dielectric resonator antenna.

Methods

Simulations in human voxel model Duke involving 8-, 16-, and 38-channel dipolectric antenna arrays for brain MRI were conducted. An 8-channel dipolectric antenna for occipital lobe MRI at 7 T was designed and constructed. The array was built of four dielectric resonator antennas (dielectric constant = 1070) and four segmented dipole antennas. In vivo MRI experiments were conducted in one subject, and the SNR performance was benchmarked against a commercial 32-channel head coil.

Results

A 38-channel dipolectric antenna array provided the highest whole-brain SNR (up to a 2.3-fold SNR gain in the center of the Duke’s head vs. an 8-channel dipolectric antenna array). Dipolectric antenna arrays driven in dipole-only mode (with dielectric resonators used as receive-only) yielded the highest transmit performance. The constructed 8-channel dipolectric antenna array provided up to threefold higher in vivo peripheral SNR when compared with a 32-channel commercial head coil.

Conclusion

Dipolectric antenna can be considered a promising approach to enhance SNR in human brain MRI at 7 T. This strategy can be used to develop novel multi-channel arrays for different high-field MRI applications.

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