title: 3-Tesla MRI in patients with fully implanted deep brain stimulation devices: a preliminary study in 10 patients.
abstract: OBJECTIVE The aim of this study was to evaluate the safety of 3-T MRI in patients with implanted deep brain stimulation (DBS) systems. METHODS This study was performed in 2 phases. In an initial phantom study, a Lucite phantom filled with tissue-mimicking gel was assembled. The system was equipped with a single DBS electrode connected to an internal pulse generator. The tip of the electrode was coupled to a fiber optic thermometer with a temperature resolution of 0.1°C. Both anatomical (T1- and T2-weighted) and functional MRI sequences were tested. A temperature change within 2°C from baseline was considered safe. After findings from the phantom study suggested safety, 10 patients with implanted DBS systems targeting various brain areas provided informed consent and underwent 3-T MRI using the same imaging sequences. Detailed neurological evaluations and internal pulse generator interrogations were performed before and after imaging. RESULTS During phantom testing, the maximum temperature increase was registered using the T2-weighted sequence. The maximal temperature changes at the tip of the DBS electrode were < 1°C for all sequences tested. In all patients, adequate images were obtained with structural imaging, although a significant artifact from lead connectors interfered with functional imaging quality. No heating, warmth, or adverse neurological effects were observed. CONCLUSIONS To the authors' knowledge, this was the first study to assess the clinical safety of 3-T MRI in patients with a fully implanted DBS system (electrodes, extensions, and pulse generator). It provided preliminary data that will allow further examination and assessment of the safety of 3-T imaging studies in patients with implanted DBS systems. The authors cannot advocate widespread use of this type of imaging in patients with DBS implants until more safety data are obtained.
authors.affiliation: Division of Neurosurgery, Department of Surgery, and.
authors.forename: Francesco
authors.initials: F
authors.lastname: Sammartino
authors.affiliation: Division of Neurosurgery, Department of Surgery, and.
authors.forename: Vibhor
authors.initials: V
authors.lastname: Krishna
authors.affiliation: Division of Neurosurgery, University of Alberta, Edmonton, Alberta, Canada.
authors.forename: Tejas
authors.initials: T
authors.lastname: Sankar
authors.affiliation: Department of Medical Imaging, University of Toronto, Ontario; and.
authors.forename: Jason
authors.initials: J
authors.lastname: Fisico
authors.affiliation: Division of Neurosurgery, Department of Surgery, and.
authors.forename: Suneil K
authors.initials: SK
authors.lastname: Kalia
authors.affiliation: Division of Neurosurgery, Department of Surgery, and.
authors.forename: Mojgan
authors.initials: M
authors.lastname: Hodaie
authors.affiliation: Department of Medical Imaging, University of Toronto, Ontario; and.
authors.forename: Walter
authors.initials: W
authors.lastname: Kucharczyk
authors.affiliation: Department of Medical Imaging, University of Toronto, Ontario; and.
authors.forename: David J
authors.initials: DJ
authors.lastname: Mikulis
authors.affiliation: Department of Medical Imaging, University of Toronto, Ontario; and.
authors.forename: Adrian
authors.initials: A
authors.lastname: Crawley
authors.affiliation: Division of Neurosurgery, Department of Surgery, and.
authors.forename: Andres M
authors.initials: AM
authors.lastname: Lozano
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D046690:Deep Brain Stimulation / Q000295:instrumentation*; D005260:Female; D006801:Humans; D058542:Implantable Neurostimulators; D008279:Magnetic Resonance Imaging / Q000009:adverse effects; D008297:Male; D008875:Middle Aged; D019047:Phantoms, Imaging; D011446:Prospective Studies
keywords: Activa; DBS = deep brain stimulation; FRFSE = fast recovery fast spin echo; FSPGR = fast spoiled gradient–recalled; GRE-EPI = gradient-echo echo-planar imaging; IPG = internal pulse generator; PROBE-SV = point-resolved single-voxel spectroscopy; PVG = periventricular gray; RF = radiofrequency; SAR = specific absorption rate; STN = subthalamic nucleus; VIM = ventral intermediate; deep brain stimulation; electrodes; fMRI = functional MRI; functional neurosurgery; implants; magnetic resonance imaging; neurostimulator; safety; specific absorption rate