Reducing RF-induced Heating near Implanted Leads through High-Dielectric Capacitive Bleeding of Current (CBLOC)

Reducing RF-induced Heating near Implanted Leads through High-Dielectric Capacitive Bleeding of Current (CBLOC)

Patients with implanted medical devices such as deep brain stimulation or spinal cord stimulation are often unable to receive magnetic resonance imaging (MRI). This is because once the device is within the radiofrequency (RF) field of the MRI scanner, electrically conductive leads act as antenna, am...

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Veröffentlicht in:IEEE transactions on microwave theory and techniques. - 1998. - 67(2019), 3 vom: 12. März, Seite 1265-1273
1. Verfasser: Golestanirad, Laleh (VerfasserIn)
Weitere Verfasser: Angelone, Leonardo M, Kirsch, John, Downs, Sean, Keil, Boris, Bonmassar, Giorgio, Wald, Lawrence L
Format: Online-Aufsatz
Sprache:English
Veröffentlicht: 2019
Zugriff auf das übergeordnete Werk:IEEE transactions on microwave theory and techniques
Schlagworte:Journal Article MR Conditional RF heating RF safety electrode leads finite element method high dielectric material high field magnetic resonance imaging (MRI) medical implants mehr... numerical simulations specific absorption rate (SAR)
Beschreibung
Zusammenfassung:Patients with implanted medical devices such as deep brain stimulation or spinal cord stimulation are often unable to receive magnetic resonance imaging (MRI). This is because once the device is within the radiofrequency (RF) field of the MRI scanner, electrically conductive leads act as antenna, amplifying the RF energy deposition in the tissue and causing possible excessive tissue heating. Here we propose a novel concept in lead design in which 40cm lead wires are coated with a ~1.2mm layer of high dielectric constant material (155 < ε r < 250) embedded in a weakly conductive insulation (σ = 20S/m). The technique called High-Dielectric Capacitive Bleeding of Current, or CBLOC, works by forming a distributed capacitance along the lengths of the lead, efficiently dissipating RF energy before it reaches the exposed tip. Measurements during RF exposure at 64 MHz and 123 MHz demonstrated that CBLOC leads generated 20-fold less heating at 1.5 T, and 40-fold less heating at 3 T compared to control leads. Numerical simulations of RF exposure at 297 MHz (7T) predicted a 15-fold reduction in specific absorption rate (SAR) of RF energy around the tip of CBLOC leads compared to control leads
Beschreibung:Date Revised 20.07.2024
published: Print-Electronic
Citation Status PubMed-not-MEDLINE
ISSN:0018-9480
DOI:10.1109/TMTT.2018.2885517