Every 5 minutes, a patient is denied an MRI scan because of an active implanted medical device. Therefore, there is a clinical need to improve the safety of MRI scans to allow patients with implants to be imaged. Ability to safely scan patients with implants would have an overall public health impact. If we can develop a safe framework to be used to image these patients, we will be able to use MRI to monitor the stage of their diseases and the efficacy of their treatment. In this project we aim to develop a workflow that utilizes multi-channel and receiver arrays in order to safely image patients with Deep Bran Stimulators (DBS). We will utilize a pre-scan strategy (accelerated by parallel acquisition) to calculate RF current induced on DBS leads and predict electrode tip temperature. We are going to calculate/design implant friendly excitation solutions/pTx pulses and utilize them to reduce RF heating around the DBS electrodes. We will demonstrate the temperature reduction around the DBS leads using fluoroscopic probes and evaluate image quality. We will test the performance of our approach by scanning phantoms, anesthetized animals (swine) and human cadavers. We will finally scan human subjects implanted with full DBS systems (electrode, extension, IPG) using the methods developed in this proposal.
This grant proposal is motivated by the need to improve the safety and efficiency of imaging patients with neural implants with MR scanners. 3T MR systems can produce high-resolution images, however, the specific absorption rate (SAR) or the power deposited in patients with metallic implants may cause unsafe tissue heating. The goal of this research, is to extend the use of MRI to patients with conductive implants, who currently cannot be scanned.
