Conceptualization, design and simulation of a hybrid antenna system as a simultaneous RF hyperthermia applicator at 600 MHz and RF coil for Magnetic Resonance Imaging at 3 Tesla

This paper presents the conceptualization, design and simulation of a hybrid multi-frequency antenna system for Radio Frequency (RF) hyperthermia and Magnetic Resonance Imaging (MRI) applications with ultra-sharp hotspot. Two different bowtie antenna arrays have been designed, simulated and integrated. The first antenna array is designed as an RF coil for MR imaging. It is optimized to generate a highly homogeneous transmit equation field and is intended for 3 T MRI systems. This corresponds to a frequency of 128 MHz. The second array aims to induce heat by accumulating the electromagnetic energy at one location thereby forming a hotspot. The operating frequency of the second system is 600 MHz. The computed homogeneity of the B1+ field generated by the imaging antennas shows similar values compared to a birdcage coil at the same frequency. The size of the hotspot generated by the heating subsystem was 26 × 26 × 93mm3. The heating produced by the MR imaging antennas was negligible, compared to the RF hyperthermia applicator.