Effect of the extracranial deep brain stimulation lead on radiofrequency heating at 9.4 Tesla (400.2 MHz)

Shrivastava, Devashish; Abosch, Aviva; Hanson, Timothy; Tian, Jinfeng; Gupte, Akshay; Iaizzo, Paul A.; Vaughan, J. Thomas

doi:10.1002/jmri.22292

Cited by 31 publications

(29 citation statements)

References 32 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…temperatures between 0.1 and 24.7°C). Similar results were found in an ultrahigh MRI (9.4 T) with Larmor frequency of 400.2 MHz (0-5°C vs. 1-27°C) [24]. …”

Section: Discussionsupporting

confidence: 69%

See 1 more Smart Citation

Risk Assessment of Magnetic Resonance Imaging in Chronically Implanted Paddle Electrodes for Cortical Stimulation

Tronnier

Melchert²,

Petersen³

et al. 2015

Stereotact Funct Neurosurg

View full text Add to dashboard Cite

Background: Cortical epidural stimulation is used for the treatment of different neuropsychiatric disorders such as chronic neuropathic pain, tinnitus, movement disorders, and psychiatric diseases. While preoperative magnetic resonance imaging (MRI) is considered the imaging tool of choice for planning the approach and electrode placement, postoperative MRI is still a contraindication with implanted paddle leads due to the risk of thermal damage or current induction creating seizures or neurological deficits. Objectives: In this feasibility in vitro study the temperature changes and induction were determined as well as the artifacts caused by 2 parallel paddle leads (Resume II, Model 3587 A; Medtronic, Minneapolis, Minn., USA), commonly used in clinical practice with and without a pulse generator (Prime Advanced, Model 7489; Medtronic). Methods: An ultrasound gel-filled head phantom with 2 paddle leads mimicking the surgical scenario was used to evaluate temperature changes as well as induced currents in a 1.5- and 3-tesla MR scanner. In addition, 1 patient underwent a 3-tesla MRI with an implanted subdural paddle lead. Results: Negligible temperature changes were detected with turbo spin echo sequences in the 1.5- and 3-tesla scanner using a head and body coil. Induced voltages up to 6 V were measured. The imaging artifacts in the phantom were well tolerable. The patient's imaging was uneventful under the settings which are accepted for deep brain stimulation imaging. Conclusion: MRI under the conditions described here seems to be safe with the implants used in this study. In particular, the induced temperature is much lower with paddle compared to conventional leads due to the different electrode design. The induced voltage does not carry any risks. However, these findings cannot automatically be transferred to other implants or other scanning conditions, and further studies are needed. The biomedical companies should be encouraged to develop MR-conditional paddle leads. Also, further research is necessary to study the mechanism of action of cortical stimulation in the future.

show abstract

“…temperatures between 0.1 and 24.7°C). Similar results were found in an ultrahigh MRI (9.4 T) with Larmor frequency of 400.2 MHz (0-5°C vs. 1-27°C) [24]. …”

Section: Discussionsupporting

confidence: 69%

“…We did not examine the situation where leads were placed crossing the central sulcus [29,30]. Considering the data of Shrivastava et al [23,24], we cannot rule out higher temperatures than those measured in our experiments with different placement of paddle leads.…”

Section: Discussionmentioning

confidence: 84%

Risk Assessment of Magnetic Resonance Imaging in Chronically Implanted Paddle Electrodes for Cortical Stimulation

Tronnier

Melchert²,

Petersen³

et al. 2015

Stereotact Funct Neurosurg

View full text Add to dashboard Cite

show abstract

“…However, major practical challenges are virtually unaffected as stringent power monitoring remains in place (new guidelines limit the maximum rms of B 1 + field to 2μT and in cases where the scanner does not report the B field, the more conservative whole-head SAR limit of 0.1 W/kg should be applied). Considerable effort has been dedicated to understand and control safety risks by characterising MRI-induced DBS heating accounting for factors such as lead configuration [9, 24, 45], lead position with respect to the MRI RF coil [42, 46] and variability of reported absorbed power across different MRI systems [47]. There is however a consensus that the problem has a very large parameter space with many interacting factors which preclude a systematic approach to identify main culprit(s).…”

Section: Discussionmentioning

confidence: 99%

Construction and modeling of a reconfigurable MRI coil for lowering SAR in patients with deep brain stimulation implants

et al. 2017

View full text Add to dashboard Cite

Post-operative MRI of patients with deep brain simulation (DBS) implants is useful to assess complications and diagnose comorbidities, however more than one third of medical centers do not perform MRIs on this patient population due to stringent safety restrictions and liability risks. A new system of reconfigurable magnetic resonance imaging head coil composed of a rotatable linearly-polarized birdcage transmitter and a close-fitting 32-channel receive array is presented for low-SAR imaging of patients with DBS implants. The novel system works by generating a region with low electric field magnitude and steering it to coincide with the DBS lead trajectory. We demonstrate that the new coil system substantially reduces the SAR amplification around DBS electrodes compared to commercially available circularly polarized coils in a cohort of 9 patient-derived realistic DBS lead trajectories. We also show that the optimal coil configuration can be reliably identified from the image artifact on B1+ field maps. Our preliminary results suggest that such a system may provide a viable solution for high-resolution imaging of DBS patients in the future. More data is needed to quantify safety limits and recommend imaging protocols before the novel coil system can be used on patients with DBS implants.

show abstract

“…This can cause heating of the tip of the electrode [33, 34]. However, tissue damage has not been reported so far in previous DBS-fMRI studies in rats [35–37].…”

Section: Discussionmentioning

confidence: 99%

Orientation selective deep brain stimulation

et al. 2017

View full text Add to dashboard Cite

Objective Target selectivity of deep brain stimulation (DBS) therapy is critical, as the precise locus and pattern of the stimulation dictates the degree to which desired treatment responses are achieved and adverse side effects are avoided. There is a clear clinical need to improve DBS technology beyond currently available stimulation steering and shaping approaches. We introduce orientation selective neural stimulation as a concept to increase the specificity of target selection in DBS. Approach This concept, which involves orienting the electric field along an axonal pathway, was tested in the corpus callosum of the rat brain by freely controlling the direction of the electric field on a plane using a three-electrode bundle, and monitoring the response of the neurons using functional magnetic resonance imaging (fMRI). Computational models were developed to further analyze axonal excitability for varied electric field orientation. Main results Our results demonstrated that the strongest fMRI response was observed when the electric field was oriented parallel to the axons, while almost no response was detected with the perpendicular orientation of the electric field relative to the primary fiber tract. These results were confirmed by computational models of the experimental paradigm quantifying the activation of radially distributed axons while varying the primary direction of the electric field. Significance The described strategies identify a new course for selective neuromodulation paradigms in DBS based on axonal fiber orientation.

show abstract

Effect of the extracranial deep brain stimulation lead on radiofrequency heating at 9.4 Tesla (400.2 MHz)

Cited by 31 publications

References 32 publications

Risk Assessment of Magnetic Resonance Imaging in Chronically Implanted Paddle Electrodes for Cortical Stimulation

Risk Assessment of Magnetic Resonance Imaging in Chronically Implanted Paddle Electrodes for Cortical Stimulation

Construction and modeling of a reconfigurable MRI coil for lowering SAR in patients with deep brain stimulation implants

Orientation selective deep brain stimulation

Contact Info

Product

Resources

About