A parallel radiofrequency(RF) transmission approach for the safety concerns of excessive heating occur in patients with Deep Brain Simulator(DBS) due

Deep brain stimulation (DBS) treats neurological disorders such as Parkinson's disease by sending electrical impulses to deep brain nuclei. The accurate placement of electrodes is an essential factor to maximise therapeutic benefits and minimise potential side effects, which is the key to successful DBS surgery.

Magnetic resonance imaging (MRI) with the 3T system has excellent potential for DBS target verification, electrode localisation and understanding of underlying therapeutic mechanisms of DBS because of its non-invasive nature, soft-tissue contrast and high-resolution visualisation of the brain anatomy. However, current MRI technologies for DBS imaging have severe limitations due to interactions between radio frequency (RF) fields and implanted electrodes. When RF fields are coupled with long conductive leads, electric currents are created on lead wires, increasing the excessive power deposition characterised by the Specific Absorption Rate (SAR) in the tissue near the lead electrodes. High energy deposition may result in an excessive temperature rise and possible tissue injury.

Different approaches are taken to solve this problem: modifying the DBS lead design and materials and modifying the RF excitation. Recent techniques include a rotating birdcage coil design and parallel RF transmission (pTx) to alter the RF excitation. The pTx method consists of a collection of separate RF channels that can modify the spatial distribution of the RF B1-field and E-field.

In this work, EM simulations will be investigated using triple-row 16-channel transmit-head-coil-array at 3T MRI using bilateral realistic DBS devices on a human model with detailed tissue properties to achieve SAR reduction in the tissue while reaching artefact-free imaging quality. Next, based on the optimal parameters of the RF coil derived from EM simulations, the pTx RF-coil array will be built to test the proposed concept experimentally.