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

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

10.1101/474015 ◽

2018 ◽

Cited By ~ 2

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.

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Somatosensory functional MRI tractography for individualized targeting of deep brain stimulation in patients with chronic pain after brachial plexus injury

Acta Neurochirurgica ◽

10.1007/s00701-019-04065-2 ◽

2019 ◽

Vol 161 (12) ◽

pp. 2485-2490

Author(s):

Witold H. Polanski ◽

Amir Zolal ◽

Johann Klein ◽

Hagen H. Kitzler ◽

Gabriele Schackert ◽

...

Keyword(s):

Chronic Pain ◽

Deep Brain Stimulation ◽

Brachial Plexus ◽

Functional Mri ◽

Brain Stimulation ◽

Brachial Plexus Injury ◽

Deep Brain

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Differential effects of deep brain stimulation and levodopa on brain activity in Parkinson’s disease

Brain Communications ◽

10.1093/braincomms/fcaa005 ◽

2020 ◽

Vol 2 (1) ◽

Author(s):

Karsten Mueller ◽

Dušan Urgošík ◽

Tommaso Ballarini ◽

Štefan Holiga ◽

Harald E Möller ◽

...

Keyword(s):

Parkinson’S Disease ◽

Parkinson's Disease ◽

Deep Brain Stimulation ◽

Functional Mri ◽

Brain Stimulation ◽

Significant Interaction ◽

Brain Activity ◽

Finger Tapping ◽

Levodopa Treatment ◽

Deep Brain

Abstract Levodopa is the first-line treatment for Parkinson’s disease, although the precise mechanisms mediating its efficacy remain elusive. We aimed to elucidate treatment effects of levodopa on brain activity during the execution of fine movements and to compare them with deep brain stimulation of the subthalamic nuclei. We studied 32 patients with Parkinson’s disease using functional MRI during the execution of finger-tapping task, alternating epochs of movement and rest. The task was performed after withdrawal and administration of a single levodopa dose. A subgroup of patients (n = 18) repeated the experiment after electrode implantation with stimulator on and off. Investigating levodopa treatment, we found a significant interaction between both factors of treatment state (off, on) and experimental task (finger tapping, rest) in bilateral putamen, but not in other motor regions. Specifically, during the off state of levodopa medication, activity in the putamen at rest was higher than during tapping. This represents an aberrant activity pattern probably indicating the derangement of basal ganglia network activity due to the lack of dopaminergic input. Levodopa medication reverted this pattern, so that putaminal activity during finger tapping was higher than during rest, as previously described in healthy controls. Within-group comparison with deep brain stimulation underlines the specificity of our findings with levodopa treatment. Indeed, a significant interaction was observed between treatment approach (levodopa, deep brain stimulation) and treatment state (off, on) in bilateral putamen. Our functional MRI study compared for the first time the differential effects of levodopa treatment and deep brain stimulation on brain motor activity. We showed modulatory effects of levodopa on brain activity of the putamen during finger movement execution, which were not observed with deep brain stimulation.

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