Magnetic resonance compatible 3-D water-coated antenna (WACOA) applicator for deep-body hyperthermia

A three-dimensional phased array for deep-body hyperthermia (HT) with water-coated antenna (WACOA) modules as basic array elements has been developed. This development was fully computer-aided applying the finite-difference time-domain (FDTD) method. Especially, the development of appropriate FDTD models for the network analysis and their experimental verification are emphasized. The WACOA applicator can be combined with the magnetic resonance (MR) tomograph for the non-invasive temperature control. Therefore, the body resonator of a high-field MR tomograph was modeled and interactions with the HT antennas investigated in order to find their optimal arrangement with regard to the rods of the MR resonator. The WACOA applicator shows load-insensitive matching, high isolation between the channels and between HT antennas and MR resonator. This high performance of network parameters results in good focusing and steering characteristics. So far, it can operate in an intermittent modus (non-simultaneously) with the tunnel-type high-field MR tomograph (125 MHz)