Feasibility of Integrating an MR Receive Coil Array into the MRcollar

Temperature monitoring is essential for a controlled application of hyperthermia in the head neck to counteract the heterogeneous thermoregulation. Magnetic resonance (MR) thermometry can be used to monitor the 3D temperature pattern, so we are developing the world's first hyperthermia applicator for MR guided treatment of head neck cancers. To maximize imaging signal-to-noise (SNR) but also allow an independent choice of the radiofrequencies for imaging and heating, our approach is based on integrating heating antenna- and imaging coil-arrays into one device. In this work, we developed and experimentally assessed the dual-function using a 3channel receiver-only coil array designed for a 1.5T MR scanner (64 MHz) integrated into one of the two MRcollar shells containing six antennas operating at 434 MHz. Vector network analyzer measurements showed an average Sii equal to -14dB and Sij equal to -12dB with a 2cm geometric overlap. MR imaging experiments showed an average SNR improvement of +40 dB when comparing the proposed coil to the conventional body coil. Results show the feasibility of the approach, and therefore paves the way for a clinical prototype for testing our dual-function approach in phantoms, volunteers and patients.