Device Configuration and Patient’s Body Composition Significantly Affect RF Heating of Deep Brain Stimulation Implants During MRI: An Experimental Study at 1.5T and 3T

2020 ◽  
Author(s):  
Bhumi Bhusal ◽  
Bach T. Nguyen ◽  
Jasmine Vu ◽  
Behzad Elahi ◽  
Joshua Rosenow ◽  
...  
Keyword(s):  
Experimental Study ◽  
Body Composition ◽  
Deep Brain Stimulation ◽  
Brain Stimulation ◽  
Rf Heating ◽  
Deep Brain

scholarly journals The effect of device configuration and patient’s body composition on image artifact and RF heating of deep brain stimulation devices during MRI at 1.5T and 3T

2020 ◽  
Author(s):  
Bhumi Bhusal ◽  
Bach T. Nguyen ◽  
Jasmine Vu ◽  
Behzad Elahi ◽  
Joshua Rosenow ◽  
...  
Keyword(s):  
Body Composition ◽  
Deep Brain Stimulation ◽  
Brain Stimulation ◽  
Statistical Tests ◽  
Subcutaneous Fat ◽  
Rf Heating ◽  
Worst Case ◽  
Image Artifact ◽  
Lead Configuration ◽  
Deep Brain

AbstractBACKGROUNDPatients with deep brain stimulation (DBS) implants have limited access to MRI due to safety concerns associated with RF-induced heating. Currently, MRI in these patients is allowed only in 1.5T horizontal scanners and with pulse sequences with reduced power. Nevertheless, off-label use of MRI at 3T is increasingly reported based on limited safety assessments. Here we present results of systematic RF heating measurements for two commercially available DBS systems during MRI at 1.5T and 3T.PURPOSETo assess the effect of imaging landmark, DBS lead configuration, and patient body composition on RF heating of DBS leads during MRI at 1.5 T and 3T.STUDY TYPEPhantom study.POPULATION/SUBJECTS/PHANTOM/SPECIMEN/ANIMAL MODELGel phantoms and cadaver brain.FIELD STRENGTH/SEQUENCE1.5T and 3T, T1-weighted turbo spin echo.ASSESSMENTRF heating was measured at tips of DBS leads implanted in brain-mimicking gel.STATISTICAL TESTSNone.RESULTSWe observed substantial fluctuation in RF heating mainly affected by phantom composition and DBS lead configuration, ranging from 0.14°C to 23.73°C at 1.5 T, and from 0.10°C to 7.39°C at 3T. The presence of subcutaneous fat substantially altered RF heating at electrode tips (−3.06°C < ΔT < 19.05°C). Introducing concentric loops in the extracranial portion of the lead at the surgical burr hole reduced RF heating by up to 89% at 1.5T and up to 98% at 3T compared to worst case heating scenarios.DATA CONCLUSIONDevice configuration and patient body composition significantly altered the RF heating of DBS leads during MRI at 1.5T and 3T. Interestingly, certain lead trajectories consistently reduced RF heating and image artifact over different imaging landmarks, RF frequencies, and phantom compositions. Such trajectories could be implemented in patients with minimal disruption to the surgical workflow.

scholarly journals Reconfigurable MRI coil technology can substantially reduce RF heating at the tips of bilateral deep brain stimulation implants

2018 ◽  
Author(s):  
Laleh Golestanirad ◽  
Boris Keil ◽  
Sean Downs ◽  
John Kirsch ◽  
Behzad Elahi ◽  
...  
Keyword(s):  
Deep Brain Stimulation ◽  
Brain Stimulation ◽  
Temperature Rise ◽  
Substantial Reduction ◽  
The Body ◽  
Rf Heating ◽  
Coil System ◽  
Body Coil ◽  
Magnetic Resonance Imaging Mri ◽  
Deep Brain

AbstractPatients with deep brain stimulation (DBS) implants can significantly benefit from magnetic resonance imaging (MRI) examination, however, access to MRI is restricted in this patients because of safety concerns due to RF heating of the leads. Recently we introduced a patient-adjustable reconfigurable MRI coil system to reduce the SAR at the tip of deep brain stimulation implants during MRI at 1.5T. A simulation study with realistic models of single (unilateral) DBS leads demonstrated a substantial reduction in the local SAR up to 500-fold could be achieved using the coil system compared to quadrature birdcage coils. Many patients however, have bilateral DBS implants and the question arises whether the rotating coil system can be used in for them. This work reports the results of phantom experiments measuring the temperature rise at the tips of bilateral DBS implants with realistic trajectories extracted from postoperative CT images of 10 patients (20 leads in total). A total of 200 measurements were performed to record temperature rise at the tips of the leads during 2 minutes of scanning with the coil rotated to cover all accessible rotation angles. In all patients, we were able to find an optimum coil rotation angle and reduced the heating of both left and right leads to a level below the heating produced by the body coil. An average heat reduction of 65% was achieved for bilateral leads. Reconfigurable coil technology introduces a promising approach for imaging of patients with DBS implants.

An Experimental Study of Deep Brain Stimulation Lead Fracture: Possible Fatigue Mechanisms and Prevention Approach

2014 ◽  
Vol 18 (4) ◽  
pp. 243-248 ◽  
Author(s):  
Changqing Jiang ◽  
Xiaolong Mo ◽  
Yantao Dong ◽  
Fangang Meng ◽  
Hongwei Hao ◽  
...  
Keyword(s):  
Experimental Study ◽  
Deep Brain Stimulation ◽  
Brain Stimulation ◽  
Lead Fracture ◽  
Prevention Approach ◽  
Deep Brain

scholarly journals Reconfigurable MRI coil technology can substantially reduce RF heating of deep brain stimulation implants: First in-vitro study of RF heating reduction in bilateral DBS leads at 1.5 T

PLoS ONE ◽  
2019 ◽  
Vol 14 (8) ◽  
pp. e0220043 ◽  
Author(s):  
Laleh Golestanirad ◽  
Ehsan Kazemivalipour ◽  
Boris Keil ◽  
Sean Downs ◽  
John Kirsch ◽  
...  
Keyword(s):  
Deep Brain Stimulation ◽  
Brain Stimulation ◽  
In Vitro Study ◽  
Vitro Study ◽  
Rf Heating ◽  
Deep Brain

scholarly journals RF heating of deep brain stimulation implants in open-bore vertical MRI systems

2019 ◽  
Author(s):  
Laleh Golestanirad ◽  
David Lampman ◽  
Ehsan Kazemivalipour ◽  
Hideta Habara ◽  
Ergin Atalar ◽  
...  
Keyword(s):  
Deep Brain Stimulation ◽  
Functional Mri ◽  
Brain Stimulation ◽  
Rf Heating ◽  
Medical Implants ◽  
Safety Hazards ◽  
Electromagnetic Simulations ◽  
Fold Reduction ◽  
Electric And Magnetic Fields ◽  
Deep Brain

AbstractPurposePatients with deep brain stimulation (DBS) implants highly benefit from MRI, however access to MRI is restricted for these patients due to safety hazards associated with RF heating of the implant. To date, all MRI studies on RF heating of medical implants have been performed in horizontal closed-bore systems. Vertical MRI scanners have a fundamentally different distribution of electric and magnetic fields and are now available at 1.2T, capable of high-resolution structural and functional MRI. This work presents the first simulation study of RF heating of DBS implants in high-field vertical scanners.MethodsWe performed finite element electromagnetic simulations to calculate SAR at tips of DBS leads during MRI in a commercially available 1.2 T vertical coil compared to a 1.5 T horizontal scanner. Both isolated leads and fully implanted systems were included.ResultsWe found 10-30-fold reduction in SAR implication at tips of isolated DBS leads, and up to 19-fold SAR reduction at tips of leads in fully implanted systems in vertical coils compared to horizontal birdcage coils.ConclusionsIf confirmed in larger patient cohorts and verified experimentally, this result can open the door to plethora of structural and functional MRI applications to guide, interpret, and advance DBS therapy.

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