MR safety in patients with implanted deep brain stimulation systems (DBS)

Introduction. While it is desirable to perform MRI examinations in patients with deep brain stimulators (DBS), a major safety concern exists regarding the potential for excessive heating secondary to magnetically induced electrical currents. This study was designed to determine the safety of MRI and DBS. Methods. Standard configurations of DBS systems were tested. In vitro testing was performed using a 1.5-Tesla MR system, a gel-filled phantom, and the body and head RF coils with varying levels of RF energy (SAR). A fluoroptic thermometry system was used to record temperatures. Results. Using the 1.5-T MRI and body RF transmit coil, the temperature changes ranged from 2.5 to 25.3 °C. Using the 1.5-T MRI and head RF transmit coil, the temperature changes ranged from 2.3 to 7.1°C. Conclusions. Excessive heating does occur with certain MR imaging conditions. Under certain conditions determined in this study, patients with DBS may safely undergo anatomical MR imaging. In the future, standardized testing and more comprehensive studies will be needed to ensure the MR safety of neurostimulation systems.