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Salama H, Salama A, Oscher L, Jallo GI, Shimony N. The role of neuromodulation in the management of drug-resistant epilepsy. Neurol Sci 2024; 45:4243-4268. [PMID: 38642321 DOI: 10.1007/s10072-024-07513-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2023] [Accepted: 04/02/2024] [Indexed: 04/22/2024]
Abstract
Drug-resistant epilepsy (DRE) poses significant challenges in terms of effective management and seizure control. Neuromodulation techniques have emerged as promising solutions for individuals who are unresponsive to pharmacological treatments, especially for those who are not good surgical candidates for surgical resection or laser interstitial therapy (LiTT). Currently, there are three neuromodulation techniques that are FDA-approved for the management of DRE. These include vagus nerve stimulation (VNS), deep brain stimulation (DBS), and responsive neurostimulation (RNS). Device selection, optimal time, and DBS and RNS target selection can also be challenging. In general, the number and localizability of the epileptic foci, alongside the comorbidities manifested by the patients, substantially influence the selection process. In the past, the general axiom was that DBS and VNS can be used for generalized and localized focal seizures, while RNS is typically reserved for patients with one or two highly localized epileptic foci, especially if they are in eloquent areas of the brain. Nowadays, with the advance in our understanding of thalamic involvement in DRE, RNS is also very effective for general non-focal epilepsy. In this review, we will discuss the underlying mechanisms of action, patient selection criteria, and the evidence supporting the use of each technique. Additionally, we explore emerging technologies and novel approaches in neuromodulation, such as closed-loop systems. Moreover, we examine the challenges and limitations associated with neuromodulation therapies, including adverse effects, complications, and the need for further long-term studies. This comprehensive review aims to provide valuable insights on present and future use of neuromodulation.
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Affiliation(s)
- HusamEddin Salama
- Al-Quds University-School of Medicine, Abu Dis, Jerusalem, Palestine
| | - Ahmed Salama
- Al-Quds University-School of Medicine, Abu Dis, Jerusalem, Palestine
| | - Logan Oscher
- Department of Neurosurgery, Institute for Brain Protection Sciences, Johns Hopkins All Children's Hospital, 600 5th Street South, St. Petersburg, FL, 33701, USA
| | - George I Jallo
- Department of Neurosurgery, Johns Hopkins University, Baltimore, MD, USA.
- Department of Neurosurgery, Institute for Brain Protection Sciences, Johns Hopkins All Children's Hospital, 600 5th Street South, St. Petersburg, FL, 33701, USA.
| | - Nir Shimony
- Department of Neurosurgery, Johns Hopkins University, Baltimore, MD, USA
- Department of Surgery, St. Jude Children's Research Hospital, Memphis, TN, USA
- Le Bonheur Neuroscience Institute, Le Bonheur Children's Hospital, Memphis, TN, USA
- Department of Neurosurgery, University of Tennessee Health Science Center, Memphis, TN, USA
- Semmes-Murphey Clinic, Memphis, TN, USA
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Zulkarnain NIH, Sadeghi-Tarakameh A, Thotland J, Harel N, Eryaman Y. A workflow for predicting radiofrequency-induced heating around bilateral deep brain stimulation electrodes in MRI. Med Phys 2024; 51:1007-1018. [PMID: 38153187 PMCID: PMC10922480 DOI: 10.1002/mp.16913] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2023] [Revised: 10/04/2023] [Accepted: 12/10/2023] [Indexed: 12/29/2023] Open
Abstract
BACKGROUND Heating around deep brain stimulation (DBS) in magnetic resonance imaging (MRI) occurs when the time-varying electromagnetic (EM) fields induce currents in the electrodes which can generate heat and potentially cause tissue damage. Predicting the heating around the electrode contacts is important to ensure the safety of patients with DBS implants undergoing an MRI scan. We previously proposed a workflow to predict heating around DBS contacts and introduced a parameter, equivalent transimpedance, that is independent of electrode trajectories, termination, and radiofrequency (RF) excitations. The workflow performance was validated in a unilateral DBS system. PURPOSE To predict RF heating around the contacts of bilateral (DBS) electrodes during an MRI scan in an anthropomorphic head phantom. METHODS Bilateral electrodes were fixed in a skull phantom filled with hydroxyethyl cellulose (HEC) gel. The electrode shafts were suspended extracranially, in a head and torso phantom filled with the same gel material. The current induced on the electrode shaft was experimentally measured using an MR-based technique 3 cm above the tip. A transimpedance value determined in a previous offline calibration was used to scale the shaft current and calculate the contact voltage. The voltage was assigned as a boundary condition on the electrical contacts of the electrode in a quasi-static (EM) simulation. The resulting specific absorption rate (SAR) distribution became the input for a transient thermal simulation and was used to predict the heating around the contacts. RF heating experiments were performed for eight different lead trajectories using circularly polarized (CP) excitation and two linear excitations for one trajectory. The measured temperatures for all experiments were compared with the simulated temperatures and the root-mean-squared errors (RMSE) were calculated. RESULTS The RF heating around the contacts of both bilateral electrodes was predicted with ≤ 0.29°C of RMSE for 20 heating scenarios. CONCLUSION The workflow successfully predicted the heating for different bilateral DBS trajectories and excitation patterns in an anthropomorphic head phantom.
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Affiliation(s)
- Nur Izzati Huda Zulkarnain
- Center for Magnetic Resonance Research (CMRR), University of Minnesota, Minneapolis, Minnesota, 55455, USA
| | - Alireza Sadeghi-Tarakameh
- Center for Magnetic Resonance Research (CMRR), University of Minnesota, Minneapolis, Minnesota, 55455, USA
| | - Jeromy Thotland
- Center for Magnetic Resonance Research (CMRR), University of Minnesota, Minneapolis, Minnesota, 55455, USA
| | - Noam Harel
- Center for Magnetic Resonance Research (CMRR), University of Minnesota, Minneapolis, Minnesota, 55455, USA
| | - Yigitcan Eryaman
- Center for Magnetic Resonance Research (CMRR), University of Minnesota, Minneapolis, Minnesota, 55455, USA
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Zaidi T, Bonmassar G, Golestanirad L. Multi-Segment Leads To Reduce RF Heating in MRI: A Computational Evaluation at 1.5T and 3T. ANNUAL INTERNATIONAL CONFERENCE OF THE IEEE ENGINEERING IN MEDICINE AND BIOLOGY SOCIETY. IEEE ENGINEERING IN MEDICINE AND BIOLOGY SOCIETY. ANNUAL INTERNATIONAL CONFERENCE 2023; 2023:1-4. [PMID: 38082812 DOI: 10.1109/embc40787.2023.10340219] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/18/2023]
Abstract
Implanted neurostimulators are currently in widespread use and allow patients to receive therapeutic nerve stimulation for a variety of conditions. Such devices often make use of long leads extending from the device to the relevant nerve to deliver their stimulation. These leads carry a significant radiofrequency (RF) safety concern for patients who also receive magnetic resonance imaging (MRI) scans. The incident RF energy from the MRI body coil can couple with the lead and produce dangerous levels of heating at the tip of the lead during a scan. Recent studies have shown one useful approach to mitigate this heating is to vary the conductivity of the wire along its length to decrease the coupling of the incoming RF energy from the MRI coil with the long lead. In this study, we adopt a similar approach and extend it by segmenting a long cylindrical lead model into two sections of differing conductivities and assessing the maximum 1g specific absorption rate (SAR) at the lead tip at both 64 MHz and 127 MHz. We also evaluated the effect of insulation thickness as well as conductivity of the phantom on the maximum 1g SAR. An 11-fold reduction in the SAR was achieved when using high conductivity ratios between the two wire segments for the 127 MHz coil and a 2-fold reduction was seen for the 64 MHz coil.Clinical relevance- Design of an implantable segmented lead has potential to mitigate RF heating concerns and open a wider patient population to both 1.5T and 3T MRI scans.
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Bhusal B, Jiang F, Vu J, Sanpitak P, Golestanirad L. Implants talk to each-other: RF heating changes when two DBS leads are present simultaneously during MRI. ANNUAL INTERNATIONAL CONFERENCE OF THE IEEE ENGINEERING IN MEDICINE AND BIOLOGY SOCIETY. IEEE ENGINEERING IN MEDICINE AND BIOLOGY SOCIETY. ANNUAL INTERNATIONAL CONFERENCE 2023; 2023:1-5. [PMID: 38082747 PMCID: PMC10838603 DOI: 10.1109/embc40787.2023.10340769] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/18/2023]
Abstract
Deep brain stimulation (DBS) has proven to be an effective treatment for Parkinson's disease and other brain disorders. The procedure often involves implanting two elongated leads aimed at specific brain nuclei in both the left and right hemispheres. However, evaluating the safety of MRI in patients with such implants has only been done on an individual lead basis, ignoring the possibility of crosstalk between the leads. This study evaluates the impact of crosstalk on power deposition at the lead tip through numerical simulation and phantom experiments. We used CT images to obtain patient-specific lead trajectories and compared the power deposition at the lead tip in cases with bilateral and unilateral DBS implants. Our results indicate that the RF power deposition at the lead tip can vary by up to 6-fold when two DBS leads are present together compared to when only one lead is present. Experimental measurements in a simplified case of two lead-only DBS systems confirmed the existence of crosstalk.Clinical Relevance-Our results indicate that RF heating of implanted leads during MRI can be affected by the presence of another lead in the body, which may increase or decrease the power deposition in the tissue depending on the position and configuration of the leads.
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Vu J, Bhusal B, Rosenow J, Pilitsis J, Golestanirad L. Optimizing the trajectory of deep brain stimulation leads reduces RF heating during MRI at 3 T: Characteristics and clinical translation. ANNUAL INTERNATIONAL CONFERENCE OF THE IEEE ENGINEERING IN MEDICINE AND BIOLOGY SOCIETY. IEEE ENGINEERING IN MEDICINE AND BIOLOGY SOCIETY. ANNUAL INTERNATIONAL CONFERENCE 2023; 2023:1-5. [PMID: 38083480 PMCID: PMC10838567 DOI: 10.1109/embc40787.2023.10340979] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/18/2023]
Abstract
Radiofrequency (RF) induced tissue heating around deep brain stimulation (DBS) leads is a well-known safety risk during magnetic resonance imaging (MRI), hindering routine protocols for patients. Known factors that contribute to variations in the magnitude of RF heating across patients include the implanted lead's trajectory and its orientation with respect to the MRI electric fields. Currently, there are no consistent requirements for surgically implanting the extracranial portion of the DBS lead. Recent studies have shown that incorporating concentric loops in the extracranial trajectory of the lead can reduce RF heating, but the optimal positioning of the loop is unknown. In this study, we evaluated RF heating of 77 unique lead trajectories to determine how different characteristics of the trajectory affect RF heating during MRI at 3 T. We performed phantom experiments with commercial DBS systems from two manufacturers to determine how consistently modifying the lead trajectory mitigates RF heating. We also presented the first surgical implementation of these modified trajectories in patients. Low-heating trajectories included small concentric loops near the surgical burr hole which were readily implemented during the surgical procedure; these trajectories generated nearly a 2-fold reduction in RF heating compared to unmodified trajectories.Clinical Relevance- Surgically modifying the DBS lead trajectory can be a cost-effective strategy for reducing RF-induced heating during MRI at 3 T.
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Vu J, Bhusal B, Nguyen BT, Sanpitak P, Nowac E, Pilitsis J, Rosenow J, Golestanirad L. A comparative study of RF heating of deep brain stimulation devices in vertical vs. horizontal MRI systems. PLoS One 2022; 17:e0278187. [PMID: 36490249 PMCID: PMC9733854 DOI: 10.1371/journal.pone.0278187] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2022] [Accepted: 11/11/2022] [Indexed: 12/13/2022] Open
Abstract
The majority of studies that assess magnetic resonance imaging (MRI) induced radiofrequency (RF) heating of the tissue when active electronic implants are present have been performed in horizontal, closed-bore MRI systems. Vertical, open-bore MRI systems have a 90° rotated magnet and a fundamentally different RF coil geometry, thus generating a substantially different RF field distribution inside the body. Little is known about the RF heating of elongated implants such as deep brain stimulation (DBS) devices in this class of scanners. Here, we conducted the first large-scale experimental study investigating whether RF heating was significantly different in a 1.2 T vertical field MRI scanner (Oasis, Fujifilm Healthcare) compared to a 1.5 T horizontal field MRI scanner (Aera, Siemens Healthineers). A commercial DBS device mimicking 30 realistic patient-derived lead trajectories extracted from postoperative computed tomography images of patients who underwent DBS surgery at our institution was implanted in a multi-material, anthropomorphic phantom. RF heating around the DBS lead was measured during four minutes of high-SAR RF exposure. Additionally, we performed electromagnetic simulations with leads of various internal structures to examine this effect on RF heating. When controlling for RMS B1+, the temperature increase around the DBS lead-tip was significantly lower in the vertical scanner compared to the horizontal scanner (0.33 ± 0.24°C vs. 4.19 ± 2.29°C). Electromagnetic simulations demonstrated up to a 17-fold reduction in the maximum of 0.1g-averaged SAR in the tissue surrounding the lead-tip in the vertical scanner compared to the horizontal scanner. Results were consistent across leads with straight and helical internal wires. Radiofrequency heating and power deposition around the DBS lead-tip were substantially lower in the 1.2 T vertical scanner compared to the 1.5 T horizontal scanner. Simulations with different lead structures suggest that the results may extend to leads from other manufacturers.
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Affiliation(s)
- Jasmine Vu
- Department of Biomedical Engineering, McCormick School of Engineering, Northwestern University, Evanston, Illinois, United States of America
- Department of Radiology, Feinberg School of Medicine, Northwestern University, Chicago, Illinois, United States of America
| | - Bhumi Bhusal
- Department of Radiology, Feinberg School of Medicine, Northwestern University, Chicago, Illinois, United States of America
| | - Bach T. Nguyen
- Department of Radiology, Feinberg School of Medicine, Northwestern University, Chicago, Illinois, United States of America
| | - Pia Sanpitak
- Department of Biomedical Engineering, McCormick School of Engineering, Northwestern University, Evanston, Illinois, United States of America
- Department of Radiology, Feinberg School of Medicine, Northwestern University, Chicago, Illinois, United States of America
| | - Elizabeth Nowac
- Illinois Bone and Joint Institute (IBJI), Wilmette, Illinois, United States of America
| | - Julie Pilitsis
- Department of Neurosciences & Experimental Therapeutics, Albany Medical College, Albany, New York, United States of America
| | - Joshua Rosenow
- Department of Neurosurgery, Feinberg School of Medicine, Northwestern University, Chicago, Illinois, United States of America
| | - Laleh Golestanirad
- Department of Biomedical Engineering, McCormick School of Engineering, Northwestern University, Evanston, Illinois, United States of America
- Department of Radiology, Feinberg School of Medicine, Northwestern University, Chicago, Illinois, United States of America
- * E-mail:
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Pinggera D, Rhomberg P, Beer R, Thomé C, Petr O. Brain Tissue Damage Induced by Multimodal Neuromonitoring In Situ during MRI after Severe Traumatic Brain Injury: Incidence and Clinical Relevance. J Clin Med 2022; 11:jcm11113169. [PMID: 35683575 PMCID: PMC9181231 DOI: 10.3390/jcm11113169] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2022] [Revised: 05/28/2022] [Accepted: 05/30/2022] [Indexed: 11/28/2022] Open
Abstract
Both neuromonitoring and early magnetic resonance imaging (MRI) provide crucial information for treatment management and prognosis in patients with severe traumatic brain injury (sTBI). So far, neuromonitoring in situ impedes the routine implementation of MRI due to safety concerns. We aimed to evaluate the brain tissue damage induced by inserted neuromonitoring devices and its clinical relevance. Nineteen patients with sTBI and being exposed to at least one MRI with neuromonitoring in situ and one follow-up MRI after neuromonitoring removal were analyzed. All MRIs were reviewed for specific tissue damage. Three females and sixteen males (aged 20–74 years, mean 42.8 years) with an initial median GCS of 5 (range 3–8) were analyzed. No lesion was observed in six patients (31.6%), whereas another six patients (31.6%) demonstrated a detectable probe trajectory. Probe-related tissue damage was visible in seven patients (36.8%) with the size of the lesion prone to further enlarge with increasing cumulative duration of MRI examinations. Upon interdisciplinary evaluation, the lesions were not considered clinically relevant. Neuromonitoring probes in situ during MRI examinations may cause local brain tissue damage, yet without any clinical implications if placed correctly. Therefore, indications must be strictly based on joint decision from all involved disciplines.
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Affiliation(s)
- Daniel Pinggera
- Department of Neurosurgery, Medical University Innsbruck, 6020 Innsbruck, Austria; (C.T.); (O.P.)
- Correspondence: ; Tel.: +43-512-504-27452
| | - Paul Rhomberg
- Department of Neuroradiology, Medical University Innsbruck, 6020 Innsbruck, Austria;
| | - Ronny Beer
- Department of Neurology, Medical University Innsbruck, 6020 Innsbruck, Austria;
| | - Claudius Thomé
- Department of Neurosurgery, Medical University Innsbruck, 6020 Innsbruck, Austria; (C.T.); (O.P.)
| | - Ondra Petr
- Department of Neurosurgery, Medical University Innsbruck, 6020 Innsbruck, Austria; (C.T.); (O.P.)
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Sanpitak P, Bhusal B, Nguyen BT, Vu J, Chow K, Bi X, Golestanirad L. On the accuracy of Tier 4 simulations to predict RF heating of wire implants during magnetic resonance imaging at 1.5 T. ANNUAL INTERNATIONAL CONFERENCE OF THE IEEE ENGINEERING IN MEDICINE AND BIOLOGY SOCIETY. IEEE ENGINEERING IN MEDICINE AND BIOLOGY SOCIETY. ANNUAL INTERNATIONAL CONFERENCE 2021; 2021:4982-4985. [PMID: 34892326 DOI: 10.1109/embc46164.2021.9630220] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/14/2023]
Abstract
Magnetic Resonance Imaging (MRI) access remains conditional to patients with conductive medical implants, as RF heating generated around the implant during scanning may cause tissue burns. Experiments have been traditionally used to assess this heating, but they are time-consuming and expensive, and in many cases cannot faithfully replicate the in-vivo scenario. Alternatively, ISO TS 10974 outlines a four-tier RF heating assessment approach based on a combination of experiments and full-wave electromagnetic (EM) simulations with varying degrees of complexity. From these, Tier 4 approach relies entirely on EM simulations. There are, however, very few studies validating such numerical models against direct thermal measurements. In this work, we evaluated the agreement between simulated and measured RF heating around wire implants during RF exposure at 63.6 MHz (proton imaging at 1.5 T). Heating was assessed around wire implants with 25 unique trajectories within an ASTM phantom. The root mean square percentage error (RMSPE) of simulated vs. measured RF heating remained <1.6% despite the wide range of observed heating (0.2 °C-53 °C). Our results suggest that good agreement can be achieved between experiments and simulations as long as important experimental features such as characteristics of the MRI RF coil, implant's geometry, position, and trajectory, as well as electric and thermal properties of gel are closely mimicked in simulations.Clinical Relevance- This work validates the application of full-wave EM simulations for modeling and predicting RF heating of conductive wires in an MRI environment, providing researchers with a validated tool to assess MRI safety in patients with implants.
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Vu J, Bhusal B, Rosenow J, Pilitsis J, Golestanirad L. Modifying surgical implantation of deep brain stimulation leads significantly reduces RF-induced heating during 3 T MRI. ANNUAL INTERNATIONAL CONFERENCE OF THE IEEE ENGINEERING IN MEDICINE AND BIOLOGY SOCIETY. IEEE ENGINEERING IN MEDICINE AND BIOLOGY SOCIETY. ANNUAL INTERNATIONAL CONFERENCE 2021; 2021:4978-4981. [PMID: 34892325 DOI: 10.1109/embc46164.2021.9629553] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/14/2023]
Abstract
Radiofrequency (RF) heating of tissue during magnetic resonance imaging (MRI) is a known safety risk in the presence of active implantable medical devices (AIMDs). As a result, access to MRI is limited for patients with these implants including those with deep brain stimulation (DBS) systems. Numerous factors contribute to excessive RF tissue heating at the DBS lead-tip, most notable being the trajectory of the lead. Phantom studies have demonstrated that looping the extracranial portion of the DBS lead at the surgical burr hole reduces the heating at the lead-tip; however, clinical implementation of this technique is challenging due to surgical constraints. As such, the intended looped trajectory is usually different from what is implanted in patients. To date, no data is available to quantify the extent by which surgical trajectory modification reduces RF heating of DBS leads compared to the typical surgical approach. In this work, we measured RF heating of a commercial DBS system during 3 T MRI, where the trajectory of the lead and extension cable mimicked lead trajectories constructed from postoperative CT images of 13 patients undergoing modified DBS surgery and 2 patients with unmodified trajectories. Two manually created trajectories mimicking typical heating cases seen in the literature were also evaluated. We found that modified lead trajectories reduced the average heating by 3-folds compared to unmodified lead trajectories.Clinical Relevance- This study evaluates the performance of a surgical modification in the routing of DBS leads in reducing RF-induced heating during MRI at 3 T.
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Mittendorff L, Young A, Sim J. A narrative review of current and emerging MRI safety issues: What every MRI technologist (radiographer) needs to know. J Med Radiat Sci 2021; 69:250-260. [PMID: 34498813 PMCID: PMC9163467 DOI: 10.1002/jmrs.546] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2021] [Revised: 08/19/2021] [Accepted: 08/31/2021] [Indexed: 12/13/2022] Open
Abstract
Magnetic resonance imaging (MRI) has been traditionally regarded as a safe imaging modality due to the absence of ionising radiation. However, MRI is a source of potential hazards with a variety of risks including, but not limited to, those associated with the various electromagnetic fields used for imaging. All MRI technologists (radiographers) require sound knowledge of the physical principles of the MRI scanner and must understand the associated safety risks and how to avoid adverse events from occurring. MRI technologists now assume more responsibility in clinical decision‐making, and their knowledge base has consequently had to expand significantly. In addition, rapid advancements in MRI technology and other correlated areas such as medical implant technology, and the associated increase in MRI safety issues, place increasing demands on the MRI technologist to constantly keep abreast of current and future developments. This article reviews current and emerging MRI safety issues relevant to the three MRI electromagnetic fields and highlights the key information that all MRI technologists should be fully cognisant of to ensure competent and safe practice within the MRI environment.
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Affiliation(s)
- Lisa Mittendorff
- Department of Anatomy and Medical Imaging, School of Medical Sciences, The University of Auckland, Auckland, New Zealand.,Mercy Radiology, Silverdale, Auckland, New Zealand
| | - Adrienne Young
- Department of Anatomy and Medical Imaging, School of Medical Sciences, The University of Auckland, Auckland, New Zealand
| | - Jenny Sim
- Department of Anatomy and Medical Imaging, School of Medical Sciences, The University of Auckland, Auckland, New Zealand.,Department of Medical Imaging and Radiation Sciences, School of Primary and Allied Health Care, Monash University, Clayton, VIC, Australia
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Huang X, Jiang GJ. Magnetic resonance imaging interactions with a sacral neuromodulation system. Neurourol Urodyn 2021; 40:1862-1868. [PMID: 34487571 PMCID: PMC9290516 DOI: 10.1002/nau.24756] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2021] [Revised: 07/01/2021] [Accepted: 07/13/2021] [Indexed: 11/08/2022]
Abstract
Aims Sacral neuromodulation (SNM) has successfully treated patients with functional urinary and/or bowel disorders for more than two decades. Historically, patients with the InterStim system (Medtronic) were contraindicated for Magnetic Resonance Imaging (MRI) scans. In 2012, Medtronic obtained Food and Drug Administration (FDA) approval for allowing 1.5 Tesla (T) MRI head scans. In September 2019, the Axonics System (Axonics) received FDA approval for 1.5 T full‐body MR Conditional labeling and then 3 T full‐body MR Conditional labeling in July 2020. In August 2020, Medtronic received 1.5 and 3 T full‐body MR Conditional labeling from the FDA for their new SNM systems (InterStim II and Micro devices with SureScanTM leads). With the advancements in MRI technology and availability of full‐body MRI eligible SNM systems, it is important for physicians to better understand MRI safety for these systems. Methods This paper explains the fundamentals of MRI physics, its interactions with active implantable medical devices (AIMDs), the subsequent potential safety hazards with emphasis on radio frequency (RF)‐related safety, and the risks associated with “Off‐label” scans, including abandoned and broken leads. Results MRI guidelines provided by the AIMD device manufacturer should be followed to ensure MRI scan safety and avoid any unnecessary risk to patients. Conclusions MRI guidelines provided by the device manufacturer are the best resource for guidance for performing safe MRI scanning. Specific conditions should be fully understood and generalizations on MRI safety claims based on partial analysis or case studies should be avoided.
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Bhusal B, Stockmann J, Guerin B, Mareyam A, Kirsch J, Wald LL, Nolt MJ, Rosenow J, Lopez-Rosado R, Elahi B, Golestanirad L. Safety and image quality at 7T MRI for deep brain stimulation systems: Ex vivo study with lead-only and full-systems. PLoS One 2021; 16:e0257077. [PMID: 34492090 PMCID: PMC8423254 DOI: 10.1371/journal.pone.0257077] [Citation(s) in RCA: 19] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2020] [Accepted: 08/23/2021] [Indexed: 11/19/2022] Open
Abstract
Ultra-high field MRI at 7 T can produce much better visualization of sub-cortical structures compared to lower field, which can greatly help target verification as well as overall treatment monitoring for patients with deep brain stimulation (DBS) implants. However, use of 7 T MRI for such patients is currently contra-indicated by guidelines from the device manufacturers due to the safety issues. The aim of this study was to provide an assessment of safety and image quality of ultra-high field magnetic resonance imaging at 7 T in patients with deep brain stimulation implants. We performed experiments with both lead-only and complete DBS systems implanted in anthropomorphic phantoms. RF heating was measured for 43 unique patient-derived device configurations. Magnetic force measurements were performed according to ASTM F2052 test method, and device integrity was assessed before and after experiments. Finally, we assessed electrode artifact in a cadaveric brain implanted with an isolated DBS lead. RF heating remained below 2°C, similar to a fever, with the 95% confidence interval between 0.38°C-0.52°C. Magnetic forces were well below forces imposed by gravity, and thus not a source of concern. No device malfunctioning was observed due to interference from MRI fields. Electrode artifact was most noticeable on MPRAGE and T2*GRE sequences, while it was minimized on T2-TSE images. Our work provides the safety assessment of ultra-high field MRI at 7 T in patients with DBS implants. Our results suggest that 7 T MRI may be performed safely in patients with DBS implants for specific implant models and MRI hardware.
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Affiliation(s)
- Bhumi Bhusal
- Department of Radiology, Northwestern University, Chicago, IL, United States of America
| | - Jason Stockmann
- Department of Radiology, Harvard Medical School, Boston, MA, United States of America
- Athinoula A. Martinos Center for Biomedical Imaging, Massachusetts General Hospital, Boston, MA, United States of America
| | - Bastien Guerin
- Department of Radiology, Harvard Medical School, Boston, MA, United States of America
- Athinoula A. Martinos Center for Biomedical Imaging, Massachusetts General Hospital, Boston, MA, United States of America
| | - Azma Mareyam
- Athinoula A. Martinos Center for Biomedical Imaging, Massachusetts General Hospital, Boston, MA, United States of America
| | - John Kirsch
- Athinoula A. Martinos Center for Biomedical Imaging, Massachusetts General Hospital, Boston, MA, United States of America
| | - Lawrence L. Wald
- Department of Radiology, Harvard Medical School, Boston, MA, United States of America
- Athinoula A. Martinos Center for Biomedical Imaging, Massachusetts General Hospital, Boston, MA, United States of America
| | - Mark J. Nolt
- Department of Neurosurgery, Northwestern University, Chicago, IL, United States of America
| | - Joshua Rosenow
- Department of Neurosurgery, Northwestern University, Chicago, IL, United States of America
| | - Roberto Lopez-Rosado
- Department of Physical Therapy and Human Movement Sciences, Northwestern University, Chicago, IL, United States of America
| | - Behzad Elahi
- Department of Physical Therapy and Human Movement Sciences, Northwestern University, Chicago, IL, United States of America
| | - Laleh Golestanirad
- Department of Radiology, Northwestern University, Chicago, IL, United States of America
- Department of Biomedical Engineering, Northwestern University, Evanston, IL, United States of America
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Wang Y, Guo R, Hu W, Zheng J, Wang Q, Jiang J, Kurpad KKN, Kaula N, Long S, Chen J, Kainz W. Magnetic resonance conditionality of abandoned leads from active implantable medical devices at 1.5 T. Magn Reson Med 2021; 87:394-408. [PMID: 34378816 DOI: 10.1002/mrm.28967] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2021] [Revised: 06/26/2021] [Accepted: 07/26/2021] [Indexed: 11/07/2022]
Abstract
PURPOSE During MR scans, abandoned leads from active implantable medical devices (AIMDs) can experience excessive heating at the lead tip, depending on the type of termination applied to the proximal contacts (proximal end treatment). The influence of different proximal end treatments (ie, [1] freely exposed in the tissue, [2] terminated with metal in contact with the tissue, or [3] capped with plastic, and thereby fully insulated, on the RF-induced lead-tip heating) are studied. A technique to ensure that MR Conditional AIMD leads remain MR Conditional even when abandoned is recommended. METHODS Abandoned leads from three MR Conditional AIMDs ([1] a sacral neuromodulation system, [2] a cardiac rhythm management pacemaker system, and [3] a deep brain stimulator system) were investigated in this study. The computational lead models (ie, the transfer functions) for different proximal end treatments were measured and used to assess the in vivo lead-tip heating for four virtual human models (FATS, Duke, Ella, and Billie) and compared with the lead-tip heating of the complete MR Conditional AIMD system. RESULT The average and maximum lead-tip heating for abandoned leads proximally capped with metal is always lower than that from the complete AIMD system. Abandoned leads proximally insulated could lead to an average in vivo temperature rise up to 3.5 times higher than that from the complete AIMD system. CONCLUSION For the three investigated AIMDs under 1.5T MR scanning, our results indicate that RF-induced lead-tip heating of abandoned leads strongly depends on the proximal lead termination. A metallic cap applied to the proximal termination of the tested leads could significantly reduce the RF-induced lead-tip heating.
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Affiliation(s)
- Yu Wang
- Department of Electrical and Computer Engineering, University of Houston, Houston, Texas, USA
| | - Ran Guo
- Department of Electrical and Computer Engineering, University of Houston, Houston, Texas, USA
| | - Wei Hu
- Department of Electrical and Computer Engineering, University of Houston, Houston, Texas, USA
| | - Jianfeng Zheng
- Department of Electrical and Computer Engineering, University of Houston, Houston, Texas, USA
| | - Qingyan Wang
- Department of Electrical and Computer Engineering, University of Houston, Houston, Texas, USA
| | - Jay Jiang
- Axonics Modulation Technologies, Irvine, California, USA
| | | | | | - Stuart Long
- Department of Electrical and Computer Engineering, University of Houston, Houston, Texas, USA
| | - Ji Chen
- Department of Electrical and Computer Engineering, University of Houston, Houston, Texas, USA
| | - Wolfgang Kainz
- Center for Devices and Radiological Health, Food and Drug Administration, Silver Spring, Maryland, USA
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14
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Glide-Hurst CK, Paulson ES, McGee K, Tyagi N, Hu Y, Balter J, Bayouth J. Task group 284 report: magnetic resonance imaging simulation in radiotherapy: considerations for clinical implementation, optimization, and quality assurance. Med Phys 2021; 48:e636-e670. [PMID: 33386620 DOI: 10.1002/mp.14695] [Citation(s) in RCA: 57] [Impact Index Per Article: 19.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2020] [Revised: 12/12/2020] [Accepted: 12/16/2020] [Indexed: 12/18/2022] Open
Abstract
The use of dedicated magnetic resonance simulation (MR-SIM) platforms in Radiation Oncology has expanded rapidly, introducing new equipment and functionality with the overall goal of improving the accuracy of radiation treatment planning. However, this emerging technology presents a new set of challenges that need to be addressed for safe and effective MR-SIM implementation. The major objectives of this report are to provide recommendations for commercially available MR simulators, including initial equipment selection, siting, acceptance testing, quality assurance, optimization of dedicated radiation therapy specific MR-SIM workflows, patient-specific considerations, safety, and staffing. Major contributions include guidance on motion and distortion management as well as MRI coil configurations to accommodate patients immobilized in the treatment position. Examples of optimized protocols and checklists for QA programs are provided. While the recommendations provided here are minimum requirements, emerging areas and unmet needs are also highlighted for future development.
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Affiliation(s)
- Carri K Glide-Hurst
- Department of Human Oncology, University of Wisconsin-Madison, Madison, WI, 53792, USA
| | - Eric S Paulson
- Department of Radiation Oncology, Medical College of Wisconsin, Milwaukee, WI, 53226, USA
| | - Kiaran McGee
- Department of Diagnostic Radiology, Mayo Clinic, Rochester, MN, 55905, USA
| | - Neelam Tyagi
- Medical Physics Department, Memorial Sloan-Kettering Cancer Center, New York, NY, 10065, USA
| | - Yanle Hu
- Department of Radiation Oncology, Mayo Clinic, Phoenix, Arizona, 85054, USA
| | - James Balter
- Department of Radiation Oncology, University of Michigan, Ann Arbor, MI, 48109, USA
| | - John Bayouth
- Department of Human Oncology, University of Wisconsin-Madison, Madison, WI, 53792, USA
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15
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Zheng Y, Xia P, Dong L, Tian L, Tian C. Development and review of a sub-millimeter-sized cell-scale micro-magnetic stimulation device. Biomed Phys Eng Express 2021; 7. [PMID: 34020437 DOI: 10.1088/2057-1976/ac0409] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2021] [Accepted: 05/21/2021] [Indexed: 11/12/2022]
Abstract
The development of modern micro-processing technology has led to the design and production of sub-millimeter-sized coils. A novel type of micro-magnetic stimulation (μMS) regulatory technology has widely been researched in recent years. This technology has several advantages, including small size, no contact between tissues and the metal coil, and high spatial resolution. Considering some problems with theμMS control technology in practical applications, different kinds ofμMS devices have been developed, including anin vitrosingle-pointμMS device, anin vivoimplantable single-pointμMs device, a discrete-arrayμMS device, and anin vivoimplantable-arrayμMs device. Given the problems that currently exist in the design and implementation of this device, such as the key problems of structural design, implantation method, experimental safety, and reliability of the device, we review the development process in detail. We also discuss the precise targeting advantage of this device, which is likely to be of great significance for wide-ranging applications of magnetic stimulation technology.
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Affiliation(s)
- Yu Zheng
- School of Life Sciences, Tiangong university, Tianjin 300387, People's Republic of China
| | - Pei Xia
- School of Life Sciences, Tiangong university, Tianjin 300387, People's Republic of China
| | - Lei Dong
- State Key Laboratory of Precision Measurement Technology and Instruments, Tianjin University, Tianjin 300072, People's Republic of China
| | - Lei Tian
- School of Life Sciences, Tiangong university, Tianjin 300387, People's Republic of China
| | - Chunxiao Tian
- School of Life Sciences, Tiangong university, Tianjin 300387, People's Republic of China
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16
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Mahmoudzadeh M, Wallois F, Tir M, Krystkowiak P, Lefranc M. Cortical hemodynamic mapping of subthalamic nucleus deep brain stimulation in Parkinsonian patients, using high-density functional near-infrared spectroscopy. PLoS One 2021; 16:e0245188. [PMID: 33493171 PMCID: PMC7833160 DOI: 10.1371/journal.pone.0245188] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2020] [Accepted: 12/23/2020] [Indexed: 12/02/2022] Open
Abstract
Subthalamic nucleus deep brain stimulation (STN-DBS) is an effective treatment for idiopathic Parkinson's disease. Despite recent progress, the mechanisms responsible for the technique's effectiveness have yet to be fully elucidated. The purpose of the present study was to gain new insights into the interactions between STN-DBS and cortical network activity. We therefore combined high-resolution functional near-infrared spectroscopy with low-resolution electroencephalography in seven Parkinsonian patients on STN-DBS, and measured cortical haemodynamic changes at rest and during hand movement in the presence and absence of stimulation (the ON-stim and OFF-stim conditions, respectively) in the off-drug condition. The relative changes in oxyhaemoglobin [HbO], deoxyhaemoglobin [HbR], and total haemoglobin [HbT] levels were analyzed continuously. At rest, the [HbO], [HbR], and [HbT] over the bilateral sensorimotor (SM), premotor (PM) and dorsolateral prefrontal (DLPF) cortices decreased steadily throughout the duration of stimulation, relative to the OFF-stim condition. During hand movement in the OFF-stim condition, [HbO] increased and [HbR] decreased concomitantly over the contralateral SM cortex (as a result of neurovascular coupling), and [HbO], [HbR], and [HbT] increased concomitantly in the dorsolateral prefrontal cortex (DLPFC)-suggesting an increase in blood volume in this brain area. During hand movement with STN-DBS, the increase in [HbO] was over the contralateral SM and PM cortices was significantly lower than in the OFF-stim condition, as was the decrease in [HbO] and [HbT] in the DLPFC. Our results indicate that STN-DBS is associated with a reduction in blood volume over the SM, PM and DLPF cortices, regardless of whether or not the patient is performing a task. This particular effect on cortical networks might explain not only STN-DBS's clinical effectiveness but also some of the associated adverse effects.
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Affiliation(s)
| | | | - Mélissa Tir
- Neurosurgery Department, CHU Amiens-Picardie, Amiens, France
| | - Pierre Krystkowiak
- Neurology Department, CHU Amiens-Picardie, Amiens, France
- Laboratory of Functional Neurosciences, University of Picardie Jules Verne, Amiens, France
| | - Michel Lefranc
- Neurosurgery Department, CHU Amiens-Picardie, Amiens, France
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17
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Nguyen BT, Pilitsis J, Golestanirad L. The effect of simulation strategies on prediction of power deposition in the tissue around electronic implants during magnetic resonance imaging. ACTA ACUST UNITED AC 2020; 65:185007. [DOI: 10.1088/1361-6560/abac9f] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
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18
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Sayed D, Chakravarthy K, Amirdelfan K, Kalia H, Meacham K, Shirvalkar P, Falowski S, Petersen E, Hagedorn JM, Pope J, Leever J, Deer T. A Comprehensive Practice Guideline for Magnetic Resonance Imaging Compatibility in Implanted Neuromodulation Devices. Neuromodulation 2020; 23:893-911. [PMID: 32809275 DOI: 10.1111/ner.13233] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2020] [Revised: 06/06/2020] [Accepted: 06/16/2020] [Indexed: 12/12/2022]
Abstract
OBJECTIVES The evolution of neuromodulation devices in order to enter magnetic resonance imaging (MRI) scanners has been one of understanding limitations, engineering modifications, and the development of a consensus within the community in which the FDA could safely administer labeling for the devices. In the initial decades of neuromodulation, it has been contraindicated for MRI use with implanted devices. In this review, we take a comprehensive approach to address all the major products currently on the market in order to provide physicians with the ability to determine when an MRI can be performed for each type of device implant. MATERIALS AND METHODS We have prepared a narrative review of MRI guidelines for currently marketed implanted neuromodulation devices including spinal cord stimulators, intrathecal drug delivery systems, peripheral nerve stimulators, deep brain stimulators, vagal nerve stimulators, and sacral nerve stimulators. Data sources included relevant literature identified through searches of PubMed, MEDLINE/OVID, SCOPUS, and manual searches of the bibliographies of known primary and review articles, as well as manufacturer-provided information. RESULTS Guidelines and recommendations for each device and their respective guidelines for use in and around MR environments are presented. CONCLUSIONS This is the first comprehensive guideline with regards to various devices in the market and MRI compatibility from the American Society of Pain and Neuroscience.
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Affiliation(s)
- Dawood Sayed
- University of Kansas Medical Center, Kansas City, KS, USA
| | - Krishnan Chakravarthy
- University of California San Diego, San Diego, CA, USA.,VA San Diego Healthcare, San Diego, CA, USA
| | - Kasra Amirdelfan
- Director of Medical Research, IPM Medical Group, Inc., Walnut Creek, CA, USA
| | - Hemant Kalia
- Rochester Regional Health System, Rochester, NY, USA.,Department of Physical Medicine & Rehabilitation, University of Rochester, NY, USA
| | - Kathleen Meacham
- Department of Anesthesiology, Washington University School of Medicine, St. Louis, MO, USA
| | - Prasad Shirvalkar
- Anesthesiology (Pain Management) and Neurology, University of California San Francisco, San Francisco, CA, USA.,Neurological Surgery, University of California San Francisco, San Francisco, CA, USA
| | - Steven Falowski
- Director of Functional Neurosurgery, Neurosurgical Associates of Lancaster, Lancaster, PA, USA
| | - Erika Petersen
- Department of Neurosurgery, University of Arkansas for Medical Sciences, Little Rock, AR, USA
| | - Jonathan M Hagedorn
- Department of Anesthesiology and Perioperative Medicine, Division of Pain Medicine, Mayo Clinic, Rochester, MN, USA
| | - Jason Pope
- Evolve Restorative Center, Santa Rosa, CA, USA
| | - John Leever
- Radiology and Neurology and Neuroradiology Fellowship Program Director, Kansas University Medical Center, Kansas City, KS, USA
| | | | - Timothy Deer
- The Spine and Nerve Center of The Virginias, Charleston, WV, USA.,Anesthesiology and Pain Medicine, WVU School of Medicine, Morgantown, WV, USA
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19
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Kazemivalipour E, Vu J, Lin S, Bhusal B, Thanh Nguyen B, Kirsch J, Elahi B, Rosenow J, Atalar E, Golestanirad L. RF heating of deep brain stimulation implants during MRI in 1.2 T vertical scanners versus 1.5 T horizontal systems: A simulation study with realistic lead configurations. ANNUAL INTERNATIONAL CONFERENCE OF THE IEEE ENGINEERING IN MEDICINE AND BIOLOGY SOCIETY. IEEE ENGINEERING IN MEDICINE AND BIOLOGY SOCIETY. ANNUAL INTERNATIONAL CONFERENCE 2020; 2020:6143-6146. [PMID: 33019373 PMCID: PMC10882580 DOI: 10.1109/embc44109.2020.9175737] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
Patients with deep brain stimulation (DBS) implants are often denied access to magnetic resonance imaging (MRI) due to safety concerns associated with RF heating of implants. Although MR-conditional DBS devices are available, complying with manufacturer guidelines has proved to be difficult as pulse sequences that optimally visualize DBS target structures tend to have much higher specific absorption rate (SAR) of radiofrequency energy than current guidelines allow. The MR-labeling of DBS devices, as well as the majority of studies on RF heating of conductive implants have been limited to horizontal close-bore MRI scanners. Vertical MRI scanners, originally introduced as open low-field MRI systems, are now available at 1.2 T field strength, capable of high-resolution structural and functional imaging. No literature exists on DBS SAR in this class of scanners which have a 90° rotated transmit coil and thus, generate a fundamentally different electric and magnetic field distributions. Here we present a simulation study of RF heating in a cohort of forty patient-derived DBS lead models during MRI in a commercially available vertical openbore MRI system (1.2 T OASIS, Hitachi) and a standard horizontal 1.5 T birdcage coil. Simulations were performed at two major imaging landmarks representing head and chest imaging. We calculated the maximum of 0.1g-averaged SAR (0.1g-SARMax) around DBS lead tips when a B1+ = 4 µT was generated on an axial plane passing through patients body. For head landmark, 0.1g-SARMax reached 220±188 W/kg in the 1.5 T birdcage coil, but only 14±11 W/kg in the OASIS coil. For chest landmark, 0.1g-SARMax was 24±17 W/kg in the 1.5 T birdcage coil and 3±2 W/kg in the OASIS coil. A paired two-tail t-test revealed a significant reduction in SAR with a large effect-size during head MRI (p < 1.5×10-8, Cohen's d = 1.5) as well as chest MRI (p < 6.5×10-10, Cohen's d = 1.7) in 1.2 T Hitachi OASIS coil compared to a standard 1.5 T birdcage transmitter. Our findings suggest that open-bore vertical scanners may offer an untapped opportunity for MRI of patients with DBS implants.
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20
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Vu J, Bhusal B, Nguyen BT, Golestanirad L. Evaluating Accuracy of Numerical Simulations in Predicting Heating of Wire Implants During MRI at 1.5 T. ANNUAL INTERNATIONAL CONFERENCE OF THE IEEE ENGINEERING IN MEDICINE AND BIOLOGY SOCIETY. IEEE ENGINEERING IN MEDICINE AND BIOLOGY SOCIETY. ANNUAL INTERNATIONAL CONFERENCE 2020; 2020:6107-6110. [PMID: 33019364 PMCID: PMC10900227 DOI: 10.1109/embc44109.2020.9175724] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Patients with long conductive implants such as deep brain stimulation (DBS) leads are often denied access to magnetic resonance imaging (MRI) exams due to safety concerns associated with radiofrequency (RF) heating of implants. Experimental temperature measurements in tissue-mimicking gel phantoms under MRI RF exposure conditions are common practices to predict in-vivo heating in the tissue surrounding wire implants. Such experiments are both expensive-as they require access to MRI units-and time-consuming due to complex implant setups. Recently, full-wave numerical simulations, which include realistic MRI RF coil models and human phantoms, are suggested as an alternative to experiments. There is however, little literature available on the accuracy of such numerical models against direct thermal measurements. This study aimed to evaluate the agreement between simulations and measurements of temperature rise at the tips of wire implants exposed to RF exposure at 64 MHz (1.5 T) for different implant trajectories typically encountered in patients with DBS leads. Heating was assessed in seven patient-derived lead configurations using both simulations and RF heating measurements during imaging of an anthropomorphic head phantom with implanted wires. We found substantial variation in RF heating as a function of lead trajectory; there was a 9.5-fold and 9-fold increase in temperature rise from ID1 to ID7 during simulations and experimental measurements, respectively. There was a strong correlation (r2 = 0.74) between simulated and measured temperatures for different lead trajectories. The maximum difference between simulated and measured temperature was 0.26 °C with simulations overestimating the temperature rise.
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21
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Boutet A, Chow CT, Narang K, Elias GJB, Neudorfer C, Germann J, Ranjan M, Loh A, Martin AJ, Kucharczyk W, Steele CJ, Hancu I, Rezai AR, Lozano AM. Improving Safety of MRI in Patients with Deep Brain Stimulation Devices. Radiology 2020; 296:250-262. [PMID: 32573388 DOI: 10.1148/radiol.2020192291] [Citation(s) in RCA: 26] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
MRI is a valuable clinical and research tool for patients undergoing deep brain stimulation (DBS). However, risks associated with imaging DBS devices have led to stringent regulations, limiting the clinical and research utility of MRI in these patients. The main risks in patients with DBS devices undergoing MRI are heating at the electrode tips, induced currents, implantable pulse generator dysfunction, and mechanical forces. Phantom model studies indicate that electrode tip heating remains the most serious risk for modern DBS devices. The absence of adverse events in patients imaged under DBS vendor guidelines for MRI demonstrates the general safety of MRI for patients with DBS devices. Moreover, recent work indicates that-given adequate safety data-patients may be imaged outside these guidelines. At present, investigators are primarily focused on improving DBS device and MRI safety through the development of tools, including safety simulation models. Existing guidelines provide a standardized framework for performing safe MRI in patients with DBS devices. It also highlights the possibility of expanding MRI as a tool for research and clinical care in these patients going forward.
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Affiliation(s)
- Alexandre Boutet
- From the University Health Network, Toronto, Canada (A.B., C.T.C., K.N., G.J.B.E., C.N., J.G., A.L., W.K., A.M.L.); Joint Department of Medical Imaging, University of Toronto, Toronto, Canada (A.B., W.K.); Department of Neurosurgery, West Virginia University, Morgantown, WVa (M.R., A.R.R.); Department of Neurosurgery, Rockefeller Neuroscience Institute, Morgantown, WVa (M.R., A.R.R.); Department of Radiology and Biomedical Imaging, University of California, San Francisco, San Francisco, Calif (A.J.M.); Department of Psychology, Concordia University, Montreal, Canada (C.J.S.); Department of Neurology, Max Planck Institute for Human Cognitive and Brain Sciences, Leipzig, Germany (C.J.S.); Center for Scientific Review, National Institutes of Health, Bethesda, Md (I.H.); and Division of Neurosurgery, Department of Surgery, Toronto Western Hospital and University of Toronto, 399 Bathurst St, WW 4-437, Toronto, ON, Canada M5T 2S8 (A.M.L.)
| | - Clement T Chow
- From the University Health Network, Toronto, Canada (A.B., C.T.C., K.N., G.J.B.E., C.N., J.G., A.L., W.K., A.M.L.); Joint Department of Medical Imaging, University of Toronto, Toronto, Canada (A.B., W.K.); Department of Neurosurgery, West Virginia University, Morgantown, WVa (M.R., A.R.R.); Department of Neurosurgery, Rockefeller Neuroscience Institute, Morgantown, WVa (M.R., A.R.R.); Department of Radiology and Biomedical Imaging, University of California, San Francisco, San Francisco, Calif (A.J.M.); Department of Psychology, Concordia University, Montreal, Canada (C.J.S.); Department of Neurology, Max Planck Institute for Human Cognitive and Brain Sciences, Leipzig, Germany (C.J.S.); Center for Scientific Review, National Institutes of Health, Bethesda, Md (I.H.); and Division of Neurosurgery, Department of Surgery, Toronto Western Hospital and University of Toronto, 399 Bathurst St, WW 4-437, Toronto, ON, Canada M5T 2S8 (A.M.L.)
| | - Keshav Narang
- From the University Health Network, Toronto, Canada (A.B., C.T.C., K.N., G.J.B.E., C.N., J.G., A.L., W.K., A.M.L.); Joint Department of Medical Imaging, University of Toronto, Toronto, Canada (A.B., W.K.); Department of Neurosurgery, West Virginia University, Morgantown, WVa (M.R., A.R.R.); Department of Neurosurgery, Rockefeller Neuroscience Institute, Morgantown, WVa (M.R., A.R.R.); Department of Radiology and Biomedical Imaging, University of California, San Francisco, San Francisco, Calif (A.J.M.); Department of Psychology, Concordia University, Montreal, Canada (C.J.S.); Department of Neurology, Max Planck Institute for Human Cognitive and Brain Sciences, Leipzig, Germany (C.J.S.); Center for Scientific Review, National Institutes of Health, Bethesda, Md (I.H.); and Division of Neurosurgery, Department of Surgery, Toronto Western Hospital and University of Toronto, 399 Bathurst St, WW 4-437, Toronto, ON, Canada M5T 2S8 (A.M.L.)
| | - Gavin J B Elias
- From the University Health Network, Toronto, Canada (A.B., C.T.C., K.N., G.J.B.E., C.N., J.G., A.L., W.K., A.M.L.); Joint Department of Medical Imaging, University of Toronto, Toronto, Canada (A.B., W.K.); Department of Neurosurgery, West Virginia University, Morgantown, WVa (M.R., A.R.R.); Department of Neurosurgery, Rockefeller Neuroscience Institute, Morgantown, WVa (M.R., A.R.R.); Department of Radiology and Biomedical Imaging, University of California, San Francisco, San Francisco, Calif (A.J.M.); Department of Psychology, Concordia University, Montreal, Canada (C.J.S.); Department of Neurology, Max Planck Institute for Human Cognitive and Brain Sciences, Leipzig, Germany (C.J.S.); Center for Scientific Review, National Institutes of Health, Bethesda, Md (I.H.); and Division of Neurosurgery, Department of Surgery, Toronto Western Hospital and University of Toronto, 399 Bathurst St, WW 4-437, Toronto, ON, Canada M5T 2S8 (A.M.L.)
| | - Clemens Neudorfer
- From the University Health Network, Toronto, Canada (A.B., C.T.C., K.N., G.J.B.E., C.N., J.G., A.L., W.K., A.M.L.); Joint Department of Medical Imaging, University of Toronto, Toronto, Canada (A.B., W.K.); Department of Neurosurgery, West Virginia University, Morgantown, WVa (M.R., A.R.R.); Department of Neurosurgery, Rockefeller Neuroscience Institute, Morgantown, WVa (M.R., A.R.R.); Department of Radiology and Biomedical Imaging, University of California, San Francisco, San Francisco, Calif (A.J.M.); Department of Psychology, Concordia University, Montreal, Canada (C.J.S.); Department of Neurology, Max Planck Institute for Human Cognitive and Brain Sciences, Leipzig, Germany (C.J.S.); Center for Scientific Review, National Institutes of Health, Bethesda, Md (I.H.); and Division of Neurosurgery, Department of Surgery, Toronto Western Hospital and University of Toronto, 399 Bathurst St, WW 4-437, Toronto, ON, Canada M5T 2S8 (A.M.L.)
| | - Jürgen Germann
- From the University Health Network, Toronto, Canada (A.B., C.T.C., K.N., G.J.B.E., C.N., J.G., A.L., W.K., A.M.L.); Joint Department of Medical Imaging, University of Toronto, Toronto, Canada (A.B., W.K.); Department of Neurosurgery, West Virginia University, Morgantown, WVa (M.R., A.R.R.); Department of Neurosurgery, Rockefeller Neuroscience Institute, Morgantown, WVa (M.R., A.R.R.); Department of Radiology and Biomedical Imaging, University of California, San Francisco, San Francisco, Calif (A.J.M.); Department of Psychology, Concordia University, Montreal, Canada (C.J.S.); Department of Neurology, Max Planck Institute for Human Cognitive and Brain Sciences, Leipzig, Germany (C.J.S.); Center for Scientific Review, National Institutes of Health, Bethesda, Md (I.H.); and Division of Neurosurgery, Department of Surgery, Toronto Western Hospital and University of Toronto, 399 Bathurst St, WW 4-437, Toronto, ON, Canada M5T 2S8 (A.M.L.)
| | - Manish Ranjan
- From the University Health Network, Toronto, Canada (A.B., C.T.C., K.N., G.J.B.E., C.N., J.G., A.L., W.K., A.M.L.); Joint Department of Medical Imaging, University of Toronto, Toronto, Canada (A.B., W.K.); Department of Neurosurgery, West Virginia University, Morgantown, WVa (M.R., A.R.R.); Department of Neurosurgery, Rockefeller Neuroscience Institute, Morgantown, WVa (M.R., A.R.R.); Department of Radiology and Biomedical Imaging, University of California, San Francisco, San Francisco, Calif (A.J.M.); Department of Psychology, Concordia University, Montreal, Canada (C.J.S.); Department of Neurology, Max Planck Institute for Human Cognitive and Brain Sciences, Leipzig, Germany (C.J.S.); Center for Scientific Review, National Institutes of Health, Bethesda, Md (I.H.); and Division of Neurosurgery, Department of Surgery, Toronto Western Hospital and University of Toronto, 399 Bathurst St, WW 4-437, Toronto, ON, Canada M5T 2S8 (A.M.L.)
| | - Aaron Loh
- From the University Health Network, Toronto, Canada (A.B., C.T.C., K.N., G.J.B.E., C.N., J.G., A.L., W.K., A.M.L.); Joint Department of Medical Imaging, University of Toronto, Toronto, Canada (A.B., W.K.); Department of Neurosurgery, West Virginia University, Morgantown, WVa (M.R., A.R.R.); Department of Neurosurgery, Rockefeller Neuroscience Institute, Morgantown, WVa (M.R., A.R.R.); Department of Radiology and Biomedical Imaging, University of California, San Francisco, San Francisco, Calif (A.J.M.); Department of Psychology, Concordia University, Montreal, Canada (C.J.S.); Department of Neurology, Max Planck Institute for Human Cognitive and Brain Sciences, Leipzig, Germany (C.J.S.); Center for Scientific Review, National Institutes of Health, Bethesda, Md (I.H.); and Division of Neurosurgery, Department of Surgery, Toronto Western Hospital and University of Toronto, 399 Bathurst St, WW 4-437, Toronto, ON, Canada M5T 2S8 (A.M.L.)
| | - Alastair J Martin
- From the University Health Network, Toronto, Canada (A.B., C.T.C., K.N., G.J.B.E., C.N., J.G., A.L., W.K., A.M.L.); Joint Department of Medical Imaging, University of Toronto, Toronto, Canada (A.B., W.K.); Department of Neurosurgery, West Virginia University, Morgantown, WVa (M.R., A.R.R.); Department of Neurosurgery, Rockefeller Neuroscience Institute, Morgantown, WVa (M.R., A.R.R.); Department of Radiology and Biomedical Imaging, University of California, San Francisco, San Francisco, Calif (A.J.M.); Department of Psychology, Concordia University, Montreal, Canada (C.J.S.); Department of Neurology, Max Planck Institute for Human Cognitive and Brain Sciences, Leipzig, Germany (C.J.S.); Center for Scientific Review, National Institutes of Health, Bethesda, Md (I.H.); and Division of Neurosurgery, Department of Surgery, Toronto Western Hospital and University of Toronto, 399 Bathurst St, WW 4-437, Toronto, ON, Canada M5T 2S8 (A.M.L.)
| | - Walter Kucharczyk
- From the University Health Network, Toronto, Canada (A.B., C.T.C., K.N., G.J.B.E., C.N., J.G., A.L., W.K., A.M.L.); Joint Department of Medical Imaging, University of Toronto, Toronto, Canada (A.B., W.K.); Department of Neurosurgery, West Virginia University, Morgantown, WVa (M.R., A.R.R.); Department of Neurosurgery, Rockefeller Neuroscience Institute, Morgantown, WVa (M.R., A.R.R.); Department of Radiology and Biomedical Imaging, University of California, San Francisco, San Francisco, Calif (A.J.M.); Department of Psychology, Concordia University, Montreal, Canada (C.J.S.); Department of Neurology, Max Planck Institute for Human Cognitive and Brain Sciences, Leipzig, Germany (C.J.S.); Center for Scientific Review, National Institutes of Health, Bethesda, Md (I.H.); and Division of Neurosurgery, Department of Surgery, Toronto Western Hospital and University of Toronto, 399 Bathurst St, WW 4-437, Toronto, ON, Canada M5T 2S8 (A.M.L.)
| | - Christopher J Steele
- From the University Health Network, Toronto, Canada (A.B., C.T.C., K.N., G.J.B.E., C.N., J.G., A.L., W.K., A.M.L.); Joint Department of Medical Imaging, University of Toronto, Toronto, Canada (A.B., W.K.); Department of Neurosurgery, West Virginia University, Morgantown, WVa (M.R., A.R.R.); Department of Neurosurgery, Rockefeller Neuroscience Institute, Morgantown, WVa (M.R., A.R.R.); Department of Radiology and Biomedical Imaging, University of California, San Francisco, San Francisco, Calif (A.J.M.); Department of Psychology, Concordia University, Montreal, Canada (C.J.S.); Department of Neurology, Max Planck Institute for Human Cognitive and Brain Sciences, Leipzig, Germany (C.J.S.); Center for Scientific Review, National Institutes of Health, Bethesda, Md (I.H.); and Division of Neurosurgery, Department of Surgery, Toronto Western Hospital and University of Toronto, 399 Bathurst St, WW 4-437, Toronto, ON, Canada M5T 2S8 (A.M.L.)
| | - Ileana Hancu
- From the University Health Network, Toronto, Canada (A.B., C.T.C., K.N., G.J.B.E., C.N., J.G., A.L., W.K., A.M.L.); Joint Department of Medical Imaging, University of Toronto, Toronto, Canada (A.B., W.K.); Department of Neurosurgery, West Virginia University, Morgantown, WVa (M.R., A.R.R.); Department of Neurosurgery, Rockefeller Neuroscience Institute, Morgantown, WVa (M.R., A.R.R.); Department of Radiology and Biomedical Imaging, University of California, San Francisco, San Francisco, Calif (A.J.M.); Department of Psychology, Concordia University, Montreal, Canada (C.J.S.); Department of Neurology, Max Planck Institute for Human Cognitive and Brain Sciences, Leipzig, Germany (C.J.S.); Center for Scientific Review, National Institutes of Health, Bethesda, Md (I.H.); and Division of Neurosurgery, Department of Surgery, Toronto Western Hospital and University of Toronto, 399 Bathurst St, WW 4-437, Toronto, ON, Canada M5T 2S8 (A.M.L.)
| | - Ali R Rezai
- From the University Health Network, Toronto, Canada (A.B., C.T.C., K.N., G.J.B.E., C.N., J.G., A.L., W.K., A.M.L.); Joint Department of Medical Imaging, University of Toronto, Toronto, Canada (A.B., W.K.); Department of Neurosurgery, West Virginia University, Morgantown, WVa (M.R., A.R.R.); Department of Neurosurgery, Rockefeller Neuroscience Institute, Morgantown, WVa (M.R., A.R.R.); Department of Radiology and Biomedical Imaging, University of California, San Francisco, San Francisco, Calif (A.J.M.); Department of Psychology, Concordia University, Montreal, Canada (C.J.S.); Department of Neurology, Max Planck Institute for Human Cognitive and Brain Sciences, Leipzig, Germany (C.J.S.); Center for Scientific Review, National Institutes of Health, Bethesda, Md (I.H.); and Division of Neurosurgery, Department of Surgery, Toronto Western Hospital and University of Toronto, 399 Bathurst St, WW 4-437, Toronto, ON, Canada M5T 2S8 (A.M.L.)
| | - Andres M Lozano
- From the University Health Network, Toronto, Canada (A.B., C.T.C., K.N., G.J.B.E., C.N., J.G., A.L., W.K., A.M.L.); Joint Department of Medical Imaging, University of Toronto, Toronto, Canada (A.B., W.K.); Department of Neurosurgery, West Virginia University, Morgantown, WVa (M.R., A.R.R.); Department of Neurosurgery, Rockefeller Neuroscience Institute, Morgantown, WVa (M.R., A.R.R.); Department of Radiology and Biomedical Imaging, University of California, San Francisco, San Francisco, Calif (A.J.M.); Department of Psychology, Concordia University, Montreal, Canada (C.J.S.); Department of Neurology, Max Planck Institute for Human Cognitive and Brain Sciences, Leipzig, Germany (C.J.S.); Center for Scientific Review, National Institutes of Health, Bethesda, Md (I.H.); and Division of Neurosurgery, Department of Surgery, Toronto Western Hospital and University of Toronto, 399 Bathurst St, WW 4-437, Toronto, ON, Canada M5T 2S8 (A.M.L.)
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Winter L, Seifert F, Zilberti L, Murbach M, Ittermann B. MRI‐Related Heating of Implants and Devices: A Review. J Magn Reson Imaging 2020; 53:1646-1665. [DOI: 10.1002/jmri.27194] [Citation(s) in RCA: 35] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2019] [Revised: 04/29/2020] [Accepted: 04/30/2020] [Indexed: 12/11/2022] Open
Affiliation(s)
- Lukas Winter
- Physikalisch‐Technische Bundesanstalt (PTB) Braunschweig and Berlin Germany
| | - Frank Seifert
- Physikalisch‐Technische Bundesanstalt (PTB) Braunschweig and Berlin Germany
| | - Luca Zilberti
- Istituto Nazionale di Ricerca Metrologica Torino Italy
| | - Manuel Murbach
- ZMT Zurich MedTech AG Zurich Switzerland
- Institute for Molecular Instrumentation and Imaging (i3M) Universidad Politécnica de Valencia (UPV) Valencia Spain
| | - Bernd Ittermann
- Physikalisch‐Technische Bundesanstalt (PTB) Braunschweig and Berlin Germany
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23
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Boutet A, Hancu I, Saha U, Crawley A, Xu DS, Ranjan M, Hlasny E, Chen R, Foltz W, Sammartino F, Coblentz A, Kucharczyk W, Lozano AM. 3-Tesla MRI of deep brain stimulation patients: safety assessment of coils and pulse sequences. J Neurosurg 2020; 132:586-594. [PMID: 30797197 DOI: 10.3171/2018.11.jns181338] [Citation(s) in RCA: 26] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2018] [Accepted: 11/05/2018] [Indexed: 11/06/2022]
Abstract
OBJECTIVE Physicians are more frequently encountering patients who are treated with deep brain stimulation (DBS), yet many MRI centers do not routinely perform MRI in this population. This warrants a safety assessment to improve DBS patients' accessibility to MRI, thereby improving their care while simultaneously providing a new tool for neuromodulation research. METHODS A phantom simulating a patient with a DBS neuromodulation device (DBS lead model 3387 and IPG Activa PC model 37601) was constructed and used. Temperature changes at the most ventral DBS electrode contacts, implantable pulse generator (IPG) voltages, specific absorption rate (SAR), and B1+rms were recorded during 3-T MRI scanning. Safety data were acquired with a transmit body multi-array receive and quadrature transmit-receive head coil during various pulse sequences, using numerous DBS configurations from "the worst" to "the most common."In addition, 3-T MRI scanning (T1 and fMRI) was performed on 41 patients with fully internalized and active DBS using a quadrature transmit-receive head coil. MR images, neurological examination findings, and stability of the IPG impedances were assessed. RESULTS In the phantom study, temperature rises at the DBS electrodes were less than 2°C for both coils during 3D SPGR, EPI, DTI, and SWI. Sequences with intense radiofrequency pulses such as T2-weighted sequences may cause higher heating (due to their higher SAR). The IPG did not power off and kept a constant firing rate, and its average voltage output was unchanged. The 41 DBS patients underwent 3-T MRI with no adverse event. CONCLUSIONS Under the experimental conditions used in this study, 3-T MRI scanning of DBS patients with selected pulse sequences appears to be safe. Generally, T2-weighted sequences (using routine protocols) should be avoided in DBS patients. Complementary 3-T MRI phantom safety data suggest that imaging conditions that are less restrictive than those used in the patients in this study, such as using transmit body multi-array receive coils, may also be safe. Given the interplay between the implanted DBS neuromodulation device and the MRI system, these findings are specific to the experimental conditions in this study.
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Affiliation(s)
- Alexandre Boutet
- 1Joint Department of Medical Imaging, and
- 2University Health Network; and
| | - Ileana Hancu
- 3GE Global Research Center, Niskayuna, New York; and
| | - Utpal Saha
- 4Krembil Research Institute, Toronto, Ontario, Canada
| | - Adrian Crawley
- 1Joint Department of Medical Imaging, and
- 2University Health Network; and
| | | | | | | | - Robert Chen
- 2University Health Network; and
- 5Division of Neurology, Department of Medicine, University of Toronto
| | - Warren Foltz
- 6STTARR Innovation Centre, Department of Radiation Oncology
| | | | - Ailish Coblentz
- 1Joint Department of Medical Imaging, and
- 2University Health Network; and
| | - Walter Kucharczyk
- 1Joint Department of Medical Imaging, and
- 2University Health Network; and
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24
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Evaluation of MRI Issues for a New Wirelessly Powered, Spinal Cord Stimulation Lead With Receiver. AJR Am J Roentgenol 2019; 214:406-412. [PMID: 31846373 DOI: 10.2214/ajr.19.21503] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
OBJECTIVE. MRI is an imaging modality frequently ordered for patients with neuromodulation systems implanted for spinal cord stimulation. The purpose of this investigation was to evaluate MRI safety issues (magnetic field interactions, MRI-related heating, functional disturbances, and artifacts) for a new wirelessly powered lead with receiver used for SCS. MATERIALS AND METHODS. Lead samples underwent in vitro evaluation for MRI safety issues using standardized techniques. Magnetic field interactions (i.e., translational attraction and torque) and artifacts were tested at 3 T. MRI-related heating was performed at 1.5 T/64 MHz and 3 T/128 MHz using two different methods: numerical simulations with analytical modeling and physical testing. Possible functional disturbances were evaluated under exposures to 1.5-T/64-MHz and 3-T/128-MHz MRI conditions. RESULTS. The lead exhibited minor magnetic field interactions (22° deflection angle, no torque) at 3 T. The highest temperature change recorded at 1.5 T/64 MHz and 3 T/128 MHz was 3.8°C and 11.3°C, respectively. Exposures to MRI conditions did not damage or alter the functional aspects of the leads. The maximum artifact size seen on a gradient-echo pulse sequence extended approximately 10 mm relative to the size of the lead. CONCLUSION. The MRI tests performed on patients with the new lead with receiver revealed no substantial concerns with respect to the conditions that we provide in the safety guidelines that were based on the results of this investigation. Therefore, MRI examinations will result in acceptable heating when conducted at appropriate whole-body-averaged specific absorption rate levels (i.e., 2.0 W/kg at 1.5 T/64 MHz and 0.3 W/kg at 3 T/128 MHz, corresponding to adjusted temperature rises of 3.6°C and 1.2°C, respectively). Therefore, patients with this wirelessly powered lead and receiver implanted can safely undergo MRI examinations under specific conditions.
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25
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Golestanirad L, Kazemivalipour E, Lampman D, Habara H, Atalar E, Rosenow J, Pilitsis J, Kirsch J. RF heating of deep brain stimulation implants in open-bore vertical MRI systems: A simulation study with realistic device configurations. Magn Reson Med 2019; 83:2284-2292. [PMID: 31677308 DOI: 10.1002/mrm.28049] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2019] [Revised: 10/02/2019] [Accepted: 10/03/2019] [Indexed: 12/18/2022]
Abstract
PURPOSE Patients with deep brain stimulation (DBS) implants benefit highly from MRI, however, access to MRI is restricted for these patients because of 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. METHODS We performed finite element electromagnetic simulations to calculate specific absorption rate (SAR) at tips of DBS leads during MRI in a commercially available 1.2T vertical coil compared to a 1.5T horizontal scanner. Both isolated leads and fully implanted systems were included. RESULTS We found 10- to 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. CONCLUSIONS If 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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Affiliation(s)
- Laleh Golestanirad
- Department of Radiology, Feinberg School of Medicine, Northwestern University, Chicago, Illinois.,Department of Biomedical Engineering, McCormick School of Engineering, Northwestern University, Evanston, Illinois
| | - Ehsan Kazemivalipour
- Department of Radiology, Feinberg School of Medicine, Northwestern University, Chicago, Illinois.,Department of Electrical and Electronics Engineering, Bilkent University, Ankara, Turkey.,National Magnetic Resonance Research Center (UMRAM), Bilkent University, Ankara, Turkey
| | | | - Hideta Habara
- Hitachi, Ltd. Healthcare Business Unit, Tokyo, Japan
| | - Ergin Atalar
- Department of Electrical and Electronics Engineering, Bilkent University, Ankara, Turkey.,National Magnetic Resonance Research Center (UMRAM), Bilkent University, Ankara, Turkey
| | - Joshua Rosenow
- Department of Neurological Surgery, Feinberg School of Medicine, Northwestern University, Chicago, Illinois
| | - Julie Pilitsis
- Department of Neurosurgery, Albany Medical Center, Albany, New York
| | - John Kirsch
- A.A. Martinos Center for Biomedical Imaging, Massachusetts General Hospital, Boston, Massachusetts
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Seo J, Kim JW, Cho SW, Shim S, Choi JW, Kim SJ. Preliminary Study of Palatal Implant for Sleep Apnea Control. ANNUAL INTERNATIONAL CONFERENCE OF THE IEEE ENGINEERING IN MEDICINE AND BIOLOGY SOCIETY. IEEE ENGINEERING IN MEDICINE AND BIOLOGY SOCIETY. ANNUAL INTERNATIONAL CONFERENCE 2019; 2018:1498-1501. [PMID: 30440676 DOI: 10.1109/embc.2018.8512463] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
A fully-implantable device for treating obstructive sleep apnea (OSA) is conceptually suggested using soft palate stimulation. In this research, two in vivo studies were conducted to demonstrate electrical and physical feasibilities of the suggested device. First, electrical stimulation was delivered to the soft palate of a rabbit using a stimulator ASIC. The stimulation frequencies were swept from 20 Hz to 200 Hz to find out the appropriate parameter. Also, threshold level of the current pulse was evaluated to be 1.10 mA with an observance of a C-arm fluoroscopy. Second, a mock-up was fabricated with liquid crystal polymer (LCP), reflecting dimensions of the suggested device. The mock-up was inserted toward the soft palate of a rabbit by incising the hard palate in a lateral direction. After the mock-up was inserted, protrusion of the device was not detected and the subject stayed alive for at least a month at the time of this writing. Finally, several discussions on the palatal implant fabrication with LCP are presented.
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27
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Golestanirad L, Kazemivalipour E, Keil B, Downs S, Kirsch J, Elahi B, Pilitsis J, Wald LL. 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; 14:e0220043. [PMID: 31390346 PMCID: PMC6685612 DOI: 10.1371/journal.pone.0220043] [Citation(s) in RCA: 34] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2018] [Accepted: 07/08/2019] [Indexed: 12/12/2022] Open
Abstract
Patients with deep brain stimulation (DBS) implants can significantly benefit from magnetic resonance imaging (MRI), however access to MRI is restricted in these patients because of safety concerns due to RF heating of the leads. Recently we introduced a patient-adjustable reconfigurable transmit coil for low-SAR imaging of DBS at 1.5T. A previous simulation study demonstrated a substantial reduction in the local SAR around single DBS leads in 9 unilateral lead models. This work reports the first experimental results of temperature measurement at the tips of bilateral DBS leads 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. When considering each lead alone, an average heat reduction of 80% was achieved. Our results suggest that reconfigurable coil technology introduces a promising approach for imaging of patients with DBS implants.
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Affiliation(s)
- Laleh Golestanirad
- Department of Biomedical Engineering, McCormick School of Engineering, Northwestern University, Evanston, IL, United States of America
- Department of Radiology, Feinberg School of Medicine, Northwestern University, Chicago, IL, United States of America
| | - Ehsan Kazemivalipour
- Department of Electrical and Electronics Engineering, Bilkent University, Ankara, Turkey
| | - Boris Keil
- Department of Life Science Engineering, Institute of Medical Physics and Radiation Protection, Giessen, Germany
| | - Sean Downs
- A. A. Martinos Center for Biomedical Imaging, Massachusetts General Hospital, Boston, MA, United States of America
| | - John Kirsch
- A. A. Martinos Center for Biomedical Imaging, Massachusetts General Hospital, Boston, MA, United States of America
| | - Behzad Elahi
- Department of Neurology, Bryan Health, Lincoln, NE, United States of America
| | - Julie Pilitsis
- Department of Neurosurgery, Albany Medical Center, Albany, NY, United States of America
| | - Lawrence L. Wald
- A. A. Martinos Center for Biomedical Imaging, Massachusetts General Hospital, Boston, MA, United States of America
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Boutet A, Rashid T, Hancu I, Elias GJB, Gramer RM, Germann J, Dimarzio M, Li B, Paramanandam V, Prasad S, Ranjan M, Coblentz A, Gwun D, Chow CT, Maciel R, Soh D, Fiveland E, Hodaie M, Kalia SK, Fasano A, Kucharczyk W, Pilitsis J, Lozano AM. Functional MRI Safety and Artifacts during Deep Brain Stimulation: Experience in 102 Patients. Radiology 2019; 293:174-183. [PMID: 31385756 DOI: 10.1148/radiol.2019190546] [Citation(s) in RCA: 37] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
BackgroundWith growing numbers of patients receiving deep brain stimulation (DBS), radiologists are encountering these neuromodulation devices at an increasing rate. Current MRI safety guidelines, however, limit MRI access in these patients.PurposeTo describe an MRI (1.5 T and 3 T) experience and safety profile in a large cohort of participants with active DBS systems and characterize the hardware-related artifacts on images from functional MRI.Materials and MethodsIn this prospective study, study participants receiving active DBS underwent 1.5- or 3-T MRI (T1-weighted imaging and gradient-recalled echo [GRE]-echo-planar imaging [EPI]) between June 2017 and October 2018. Short- and long-term adverse events were tracked. The authors quantified DBS hardware-related artifacts on images from GRE-EPI (functional MRI) at the cranial coil wire and electrode contacts. Segmented artifacts were then transformed into standard space to define the brain areas affected by signal loss. Two-sample t tests were used to assess the difference in artifact size between 1.5- and 3-T MRI.ResultsA total of 102 participants (mean age ± standard deviation, 60 years ± 11; 65 men) were evaluated. No MRI-related short- and long-term adverse events or acute changes were observed. DBS artifacts were most prominent near the electrode contacts and over the frontoparietal cortical area where the redundancy of the extension wire is placed subcutaneously. The mean electrode contact artifact diameter was 9.3 mm ± 1.6, and 1.9% ± 0.8 of the brain was obscured by the coil artifact. The coil artifacts were larger at 3 T than at 1.5 T, obscuring 2.1% ± 0.7 and 1.4% ± 0.7 of intracranial volume, respectively (P < .001). The superficial frontoparietal cortex and deep structures neighboring the electrode contacts were most commonly obscured.ConclusionWith a priori local safety testing, patients receiving deep brain stimulation may safely undergo 1.5- and 3-T MRI. Deep brain stimulation hardware-related artifacts only affect a small proportion of the brain.© RSNA, 2019Online supplemental material is available for this article.See also the editorial by Martin in this issue.
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Affiliation(s)
- Alexandre Boutet
- From the Joint Department of Medical Imaging, University of Toronto, Toronto, Canada (A.B., A.C., W.K.); Division of Neurosurgery, Toronto Western Hospital, University Health Network, 399 Bathurst St, WW 4-437, Toronto, ON, Canada M5T 2S8 (A.B., G.J.B.E., R.M.G., J.G., B.L., V.P., S.P., M.R., A.C., D.G., C.T.C., R.M., D.S., M.H., S.K.K., A.F., W.K., A.M.L.); Department of Neuroscience and Experimental Therapeutics, Albany Medical College, Albany, NY (T.R., M.D., J.P.); Edmond J. Safra Program in Parkinson's Disease, Morton and Gloria Shulman Movement Disorders Clinic, Toronto Western Hospital, UHN, Division of Neurology, University of Toronto, Toronto, Ontario, Canada (I.H., V.P., S.P., R.M., D.S., A.F.); GE Global Research Center, Niskayuna, NY (E.F.); Krembil Brain Institute, Toronto, Canada (A.F.); and Department of Neurosurgery, Albany Medical Center, Albany, NY (J.P.)
| | - Tanweer Rashid
- From the Joint Department of Medical Imaging, University of Toronto, Toronto, Canada (A.B., A.C., W.K.); Division of Neurosurgery, Toronto Western Hospital, University Health Network, 399 Bathurst St, WW 4-437, Toronto, ON, Canada M5T 2S8 (A.B., G.J.B.E., R.M.G., J.G., B.L., V.P., S.P., M.R., A.C., D.G., C.T.C., R.M., D.S., M.H., S.K.K., A.F., W.K., A.M.L.); Department of Neuroscience and Experimental Therapeutics, Albany Medical College, Albany, NY (T.R., M.D., J.P.); Edmond J. Safra Program in Parkinson's Disease, Morton and Gloria Shulman Movement Disorders Clinic, Toronto Western Hospital, UHN, Division of Neurology, University of Toronto, Toronto, Ontario, Canada (I.H., V.P., S.P., R.M., D.S., A.F.); GE Global Research Center, Niskayuna, NY (E.F.); Krembil Brain Institute, Toronto, Canada (A.F.); and Department of Neurosurgery, Albany Medical Center, Albany, NY (J.P.)
| | - Ileana Hancu
- From the Joint Department of Medical Imaging, University of Toronto, Toronto, Canada (A.B., A.C., W.K.); Division of Neurosurgery, Toronto Western Hospital, University Health Network, 399 Bathurst St, WW 4-437, Toronto, ON, Canada M5T 2S8 (A.B., G.J.B.E., R.M.G., J.G., B.L., V.P., S.P., M.R., A.C., D.G., C.T.C., R.M., D.S., M.H., S.K.K., A.F., W.K., A.M.L.); Department of Neuroscience and Experimental Therapeutics, Albany Medical College, Albany, NY (T.R., M.D., J.P.); Edmond J. Safra Program in Parkinson's Disease, Morton and Gloria Shulman Movement Disorders Clinic, Toronto Western Hospital, UHN, Division of Neurology, University of Toronto, Toronto, Ontario, Canada (I.H., V.P., S.P., R.M., D.S., A.F.); GE Global Research Center, Niskayuna, NY (E.F.); Krembil Brain Institute, Toronto, Canada (A.F.); and Department of Neurosurgery, Albany Medical Center, Albany, NY (J.P.)
| | - Gavin J B Elias
- From the Joint Department of Medical Imaging, University of Toronto, Toronto, Canada (A.B., A.C., W.K.); Division of Neurosurgery, Toronto Western Hospital, University Health Network, 399 Bathurst St, WW 4-437, Toronto, ON, Canada M5T 2S8 (A.B., G.J.B.E., R.M.G., J.G., B.L., V.P., S.P., M.R., A.C., D.G., C.T.C., R.M., D.S., M.H., S.K.K., A.F., W.K., A.M.L.); Department of Neuroscience and Experimental Therapeutics, Albany Medical College, Albany, NY (T.R., M.D., J.P.); Edmond J. Safra Program in Parkinson's Disease, Morton and Gloria Shulman Movement Disorders Clinic, Toronto Western Hospital, UHN, Division of Neurology, University of Toronto, Toronto, Ontario, Canada (I.H., V.P., S.P., R.M., D.S., A.F.); GE Global Research Center, Niskayuna, NY (E.F.); Krembil Brain Institute, Toronto, Canada (A.F.); and Department of Neurosurgery, Albany Medical Center, Albany, NY (J.P.)
| | - Robert M Gramer
- From the Joint Department of Medical Imaging, University of Toronto, Toronto, Canada (A.B., A.C., W.K.); Division of Neurosurgery, Toronto Western Hospital, University Health Network, 399 Bathurst St, WW 4-437, Toronto, ON, Canada M5T 2S8 (A.B., G.J.B.E., R.M.G., J.G., B.L., V.P., S.P., M.R., A.C., D.G., C.T.C., R.M., D.S., M.H., S.K.K., A.F., W.K., A.M.L.); Department of Neuroscience and Experimental Therapeutics, Albany Medical College, Albany, NY (T.R., M.D., J.P.); Edmond J. Safra Program in Parkinson's Disease, Morton and Gloria Shulman Movement Disorders Clinic, Toronto Western Hospital, UHN, Division of Neurology, University of Toronto, Toronto, Ontario, Canada (I.H., V.P., S.P., R.M., D.S., A.F.); GE Global Research Center, Niskayuna, NY (E.F.); Krembil Brain Institute, Toronto, Canada (A.F.); and Department of Neurosurgery, Albany Medical Center, Albany, NY (J.P.)
| | - Jürgen Germann
- From the Joint Department of Medical Imaging, University of Toronto, Toronto, Canada (A.B., A.C., W.K.); Division of Neurosurgery, Toronto Western Hospital, University Health Network, 399 Bathurst St, WW 4-437, Toronto, ON, Canada M5T 2S8 (A.B., G.J.B.E., R.M.G., J.G., B.L., V.P., S.P., M.R., A.C., D.G., C.T.C., R.M., D.S., M.H., S.K.K., A.F., W.K., A.M.L.); Department of Neuroscience and Experimental Therapeutics, Albany Medical College, Albany, NY (T.R., M.D., J.P.); Edmond J. Safra Program in Parkinson's Disease, Morton and Gloria Shulman Movement Disorders Clinic, Toronto Western Hospital, UHN, Division of Neurology, University of Toronto, Toronto, Ontario, Canada (I.H., V.P., S.P., R.M., D.S., A.F.); GE Global Research Center, Niskayuna, NY (E.F.); Krembil Brain Institute, Toronto, Canada (A.F.); and Department of Neurosurgery, Albany Medical Center, Albany, NY (J.P.)
| | - Marisa Dimarzio
- From the Joint Department of Medical Imaging, University of Toronto, Toronto, Canada (A.B., A.C., W.K.); Division of Neurosurgery, Toronto Western Hospital, University Health Network, 399 Bathurst St, WW 4-437, Toronto, ON, Canada M5T 2S8 (A.B., G.J.B.E., R.M.G., J.G., B.L., V.P., S.P., M.R., A.C., D.G., C.T.C., R.M., D.S., M.H., S.K.K., A.F., W.K., A.M.L.); Department of Neuroscience and Experimental Therapeutics, Albany Medical College, Albany, NY (T.R., M.D., J.P.); Edmond J. Safra Program in Parkinson's Disease, Morton and Gloria Shulman Movement Disorders Clinic, Toronto Western Hospital, UHN, Division of Neurology, University of Toronto, Toronto, Ontario, Canada (I.H., V.P., S.P., R.M., D.S., A.F.); GE Global Research Center, Niskayuna, NY (E.F.); Krembil Brain Institute, Toronto, Canada (A.F.); and Department of Neurosurgery, Albany Medical Center, Albany, NY (J.P.)
| | - Bryan Li
- From the Joint Department of Medical Imaging, University of Toronto, Toronto, Canada (A.B., A.C., W.K.); Division of Neurosurgery, Toronto Western Hospital, University Health Network, 399 Bathurst St, WW 4-437, Toronto, ON, Canada M5T 2S8 (A.B., G.J.B.E., R.M.G., J.G., B.L., V.P., S.P., M.R., A.C., D.G., C.T.C., R.M., D.S., M.H., S.K.K., A.F., W.K., A.M.L.); Department of Neuroscience and Experimental Therapeutics, Albany Medical College, Albany, NY (T.R., M.D., J.P.); Edmond J. Safra Program in Parkinson's Disease, Morton and Gloria Shulman Movement Disorders Clinic, Toronto Western Hospital, UHN, Division of Neurology, University of Toronto, Toronto, Ontario, Canada (I.H., V.P., S.P., R.M., D.S., A.F.); GE Global Research Center, Niskayuna, NY (E.F.); Krembil Brain Institute, Toronto, Canada (A.F.); and Department of Neurosurgery, Albany Medical Center, Albany, NY (J.P.)
| | - Vijayashankar Paramanandam
- From the Joint Department of Medical Imaging, University of Toronto, Toronto, Canada (A.B., A.C., W.K.); Division of Neurosurgery, Toronto Western Hospital, University Health Network, 399 Bathurst St, WW 4-437, Toronto, ON, Canada M5T 2S8 (A.B., G.J.B.E., R.M.G., J.G., B.L., V.P., S.P., M.R., A.C., D.G., C.T.C., R.M., D.S., M.H., S.K.K., A.F., W.K., A.M.L.); Department of Neuroscience and Experimental Therapeutics, Albany Medical College, Albany, NY (T.R., M.D., J.P.); Edmond J. Safra Program in Parkinson's Disease, Morton and Gloria Shulman Movement Disorders Clinic, Toronto Western Hospital, UHN, Division of Neurology, University of Toronto, Toronto, Ontario, Canada (I.H., V.P., S.P., R.M., D.S., A.F.); GE Global Research Center, Niskayuna, NY (E.F.); Krembil Brain Institute, Toronto, Canada (A.F.); and Department of Neurosurgery, Albany Medical Center, Albany, NY (J.P.)
| | - Sreeram Prasad
- From the Joint Department of Medical Imaging, University of Toronto, Toronto, Canada (A.B., A.C., W.K.); Division of Neurosurgery, Toronto Western Hospital, University Health Network, 399 Bathurst St, WW 4-437, Toronto, ON, Canada M5T 2S8 (A.B., G.J.B.E., R.M.G., J.G., B.L., V.P., S.P., M.R., A.C., D.G., C.T.C., R.M., D.S., M.H., S.K.K., A.F., W.K., A.M.L.); Department of Neuroscience and Experimental Therapeutics, Albany Medical College, Albany, NY (T.R., M.D., J.P.); Edmond J. Safra Program in Parkinson's Disease, Morton and Gloria Shulman Movement Disorders Clinic, Toronto Western Hospital, UHN, Division of Neurology, University of Toronto, Toronto, Ontario, Canada (I.H., V.P., S.P., R.M., D.S., A.F.); GE Global Research Center, Niskayuna, NY (E.F.); Krembil Brain Institute, Toronto, Canada (A.F.); and Department of Neurosurgery, Albany Medical Center, Albany, NY (J.P.)
| | - Manish Ranjan
- From the Joint Department of Medical Imaging, University of Toronto, Toronto, Canada (A.B., A.C., W.K.); Division of Neurosurgery, Toronto Western Hospital, University Health Network, 399 Bathurst St, WW 4-437, Toronto, ON, Canada M5T 2S8 (A.B., G.J.B.E., R.M.G., J.G., B.L., V.P., S.P., M.R., A.C., D.G., C.T.C., R.M., D.S., M.H., S.K.K., A.F., W.K., A.M.L.); Department of Neuroscience and Experimental Therapeutics, Albany Medical College, Albany, NY (T.R., M.D., J.P.); Edmond J. Safra Program in Parkinson's Disease, Morton and Gloria Shulman Movement Disorders Clinic, Toronto Western Hospital, UHN, Division of Neurology, University of Toronto, Toronto, Ontario, Canada (I.H., V.P., S.P., R.M., D.S., A.F.); GE Global Research Center, Niskayuna, NY (E.F.); Krembil Brain Institute, Toronto, Canada (A.F.); and Department of Neurosurgery, Albany Medical Center, Albany, NY (J.P.)
| | - Ailish Coblentz
- From the Joint Department of Medical Imaging, University of Toronto, Toronto, Canada (A.B., A.C., W.K.); Division of Neurosurgery, Toronto Western Hospital, University Health Network, 399 Bathurst St, WW 4-437, Toronto, ON, Canada M5T 2S8 (A.B., G.J.B.E., R.M.G., J.G., B.L., V.P., S.P., M.R., A.C., D.G., C.T.C., R.M., D.S., M.H., S.K.K., A.F., W.K., A.M.L.); Department of Neuroscience and Experimental Therapeutics, Albany Medical College, Albany, NY (T.R., M.D., J.P.); Edmond J. Safra Program in Parkinson's Disease, Morton and Gloria Shulman Movement Disorders Clinic, Toronto Western Hospital, UHN, Division of Neurology, University of Toronto, Toronto, Ontario, Canada (I.H., V.P., S.P., R.M., D.S., A.F.); GE Global Research Center, Niskayuna, NY (E.F.); Krembil Brain Institute, Toronto, Canada (A.F.); and Department of Neurosurgery, Albany Medical Center, Albany, NY (J.P.)
| | - Dave Gwun
- From the Joint Department of Medical Imaging, University of Toronto, Toronto, Canada (A.B., A.C., W.K.); Division of Neurosurgery, Toronto Western Hospital, University Health Network, 399 Bathurst St, WW 4-437, Toronto, ON, Canada M5T 2S8 (A.B., G.J.B.E., R.M.G., J.G., B.L., V.P., S.P., M.R., A.C., D.G., C.T.C., R.M., D.S., M.H., S.K.K., A.F., W.K., A.M.L.); Department of Neuroscience and Experimental Therapeutics, Albany Medical College, Albany, NY (T.R., M.D., J.P.); Edmond J. Safra Program in Parkinson's Disease, Morton and Gloria Shulman Movement Disorders Clinic, Toronto Western Hospital, UHN, Division of Neurology, University of Toronto, Toronto, Ontario, Canada (I.H., V.P., S.P., R.M., D.S., A.F.); GE Global Research Center, Niskayuna, NY (E.F.); Krembil Brain Institute, Toronto, Canada (A.F.); and Department of Neurosurgery, Albany Medical Center, Albany, NY (J.P.)
| | - Clement T Chow
- From the Joint Department of Medical Imaging, University of Toronto, Toronto, Canada (A.B., A.C., W.K.); Division of Neurosurgery, Toronto Western Hospital, University Health Network, 399 Bathurst St, WW 4-437, Toronto, ON, Canada M5T 2S8 (A.B., G.J.B.E., R.M.G., J.G., B.L., V.P., S.P., M.R., A.C., D.G., C.T.C., R.M., D.S., M.H., S.K.K., A.F., W.K., A.M.L.); Department of Neuroscience and Experimental Therapeutics, Albany Medical College, Albany, NY (T.R., M.D., J.P.); Edmond J. Safra Program in Parkinson's Disease, Morton and Gloria Shulman Movement Disorders Clinic, Toronto Western Hospital, UHN, Division of Neurology, University of Toronto, Toronto, Ontario, Canada (I.H., V.P., S.P., R.M., D.S., A.F.); GE Global Research Center, Niskayuna, NY (E.F.); Krembil Brain Institute, Toronto, Canada (A.F.); and Department of Neurosurgery, Albany Medical Center, Albany, NY (J.P.)
| | - Ricardo Maciel
- From the Joint Department of Medical Imaging, University of Toronto, Toronto, Canada (A.B., A.C., W.K.); Division of Neurosurgery, Toronto Western Hospital, University Health Network, 399 Bathurst St, WW 4-437, Toronto, ON, Canada M5T 2S8 (A.B., G.J.B.E., R.M.G., J.G., B.L., V.P., S.P., M.R., A.C., D.G., C.T.C., R.M., D.S., M.H., S.K.K., A.F., W.K., A.M.L.); Department of Neuroscience and Experimental Therapeutics, Albany Medical College, Albany, NY (T.R., M.D., J.P.); Edmond J. Safra Program in Parkinson's Disease, Morton and Gloria Shulman Movement Disorders Clinic, Toronto Western Hospital, UHN, Division of Neurology, University of Toronto, Toronto, Ontario, Canada (I.H., V.P., S.P., R.M., D.S., A.F.); GE Global Research Center, Niskayuna, NY (E.F.); Krembil Brain Institute, Toronto, Canada (A.F.); and Department of Neurosurgery, Albany Medical Center, Albany, NY (J.P.)
| | - Derrick Soh
- From the Joint Department of Medical Imaging, University of Toronto, Toronto, Canada (A.B., A.C., W.K.); Division of Neurosurgery, Toronto Western Hospital, University Health Network, 399 Bathurst St, WW 4-437, Toronto, ON, Canada M5T 2S8 (A.B., G.J.B.E., R.M.G., J.G., B.L., V.P., S.P., M.R., A.C., D.G., C.T.C., R.M., D.S., M.H., S.K.K., A.F., W.K., A.M.L.); Department of Neuroscience and Experimental Therapeutics, Albany Medical College, Albany, NY (T.R., M.D., J.P.); Edmond J. Safra Program in Parkinson's Disease, Morton and Gloria Shulman Movement Disorders Clinic, Toronto Western Hospital, UHN, Division of Neurology, University of Toronto, Toronto, Ontario, Canada (I.H., V.P., S.P., R.M., D.S., A.F.); GE Global Research Center, Niskayuna, NY (E.F.); Krembil Brain Institute, Toronto, Canada (A.F.); and Department of Neurosurgery, Albany Medical Center, Albany, NY (J.P.)
| | - Eric Fiveland
- From the Joint Department of Medical Imaging, University of Toronto, Toronto, Canada (A.B., A.C., W.K.); Division of Neurosurgery, Toronto Western Hospital, University Health Network, 399 Bathurst St, WW 4-437, Toronto, ON, Canada M5T 2S8 (A.B., G.J.B.E., R.M.G., J.G., B.L., V.P., S.P., M.R., A.C., D.G., C.T.C., R.M., D.S., M.H., S.K.K., A.F., W.K., A.M.L.); Department of Neuroscience and Experimental Therapeutics, Albany Medical College, Albany, NY (T.R., M.D., J.P.); Edmond J. Safra Program in Parkinson's Disease, Morton and Gloria Shulman Movement Disorders Clinic, Toronto Western Hospital, UHN, Division of Neurology, University of Toronto, Toronto, Ontario, Canada (I.H., V.P., S.P., R.M., D.S., A.F.); GE Global Research Center, Niskayuna, NY (E.F.); Krembil Brain Institute, Toronto, Canada (A.F.); and Department of Neurosurgery, Albany Medical Center, Albany, NY (J.P.)
| | - Mojgan Hodaie
- From the Joint Department of Medical Imaging, University of Toronto, Toronto, Canada (A.B., A.C., W.K.); Division of Neurosurgery, Toronto Western Hospital, University Health Network, 399 Bathurst St, WW 4-437, Toronto, ON, Canada M5T 2S8 (A.B., G.J.B.E., R.M.G., J.G., B.L., V.P., S.P., M.R., A.C., D.G., C.T.C., R.M., D.S., M.H., S.K.K., A.F., W.K., A.M.L.); Department of Neuroscience and Experimental Therapeutics, Albany Medical College, Albany, NY (T.R., M.D., J.P.); Edmond J. Safra Program in Parkinson's Disease, Morton and Gloria Shulman Movement Disorders Clinic, Toronto Western Hospital, UHN, Division of Neurology, University of Toronto, Toronto, Ontario, Canada (I.H., V.P., S.P., R.M., D.S., A.F.); GE Global Research Center, Niskayuna, NY (E.F.); Krembil Brain Institute, Toronto, Canada (A.F.); and Department of Neurosurgery, Albany Medical Center, Albany, NY (J.P.)
| | - Suneil K Kalia
- From the Joint Department of Medical Imaging, University of Toronto, Toronto, Canada (A.B., A.C., W.K.); Division of Neurosurgery, Toronto Western Hospital, University Health Network, 399 Bathurst St, WW 4-437, Toronto, ON, Canada M5T 2S8 (A.B., G.J.B.E., R.M.G., J.G., B.L., V.P., S.P., M.R., A.C., D.G., C.T.C., R.M., D.S., M.H., S.K.K., A.F., W.K., A.M.L.); Department of Neuroscience and Experimental Therapeutics, Albany Medical College, Albany, NY (T.R., M.D., J.P.); Edmond J. Safra Program in Parkinson's Disease, Morton and Gloria Shulman Movement Disorders Clinic, Toronto Western Hospital, UHN, Division of Neurology, University of Toronto, Toronto, Ontario, Canada (I.H., V.P., S.P., R.M., D.S., A.F.); GE Global Research Center, Niskayuna, NY (E.F.); Krembil Brain Institute, Toronto, Canada (A.F.); and Department of Neurosurgery, Albany Medical Center, Albany, NY (J.P.)
| | - Alfonso Fasano
- From the Joint Department of Medical Imaging, University of Toronto, Toronto, Canada (A.B., A.C., W.K.); Division of Neurosurgery, Toronto Western Hospital, University Health Network, 399 Bathurst St, WW 4-437, Toronto, ON, Canada M5T 2S8 (A.B., G.J.B.E., R.M.G., J.G., B.L., V.P., S.P., M.R., A.C., D.G., C.T.C., R.M., D.S., M.H., S.K.K., A.F., W.K., A.M.L.); Department of Neuroscience and Experimental Therapeutics, Albany Medical College, Albany, NY (T.R., M.D., J.P.); Edmond J. Safra Program in Parkinson's Disease, Morton and Gloria Shulman Movement Disorders Clinic, Toronto Western Hospital, UHN, Division of Neurology, University of Toronto, Toronto, Ontario, Canada (I.H., V.P., S.P., R.M., D.S., A.F.); GE Global Research Center, Niskayuna, NY (E.F.); Krembil Brain Institute, Toronto, Canada (A.F.); and Department of Neurosurgery, Albany Medical Center, Albany, NY (J.P.)
| | - Walter Kucharczyk
- From the Joint Department of Medical Imaging, University of Toronto, Toronto, Canada (A.B., A.C., W.K.); Division of Neurosurgery, Toronto Western Hospital, University Health Network, 399 Bathurst St, WW 4-437, Toronto, ON, Canada M5T 2S8 (A.B., G.J.B.E., R.M.G., J.G., B.L., V.P., S.P., M.R., A.C., D.G., C.T.C., R.M., D.S., M.H., S.K.K., A.F., W.K., A.M.L.); Department of Neuroscience and Experimental Therapeutics, Albany Medical College, Albany, NY (T.R., M.D., J.P.); Edmond J. Safra Program in Parkinson's Disease, Morton and Gloria Shulman Movement Disorders Clinic, Toronto Western Hospital, UHN, Division of Neurology, University of Toronto, Toronto, Ontario, Canada (I.H., V.P., S.P., R.M., D.S., A.F.); GE Global Research Center, Niskayuna, NY (E.F.); Krembil Brain Institute, Toronto, Canada (A.F.); and Department of Neurosurgery, Albany Medical Center, Albany, NY (J.P.)
| | - Julie Pilitsis
- From the Joint Department of Medical Imaging, University of Toronto, Toronto, Canada (A.B., A.C., W.K.); Division of Neurosurgery, Toronto Western Hospital, University Health Network, 399 Bathurst St, WW 4-437, Toronto, ON, Canada M5T 2S8 (A.B., G.J.B.E., R.M.G., J.G., B.L., V.P., S.P., M.R., A.C., D.G., C.T.C., R.M., D.S., M.H., S.K.K., A.F., W.K., A.M.L.); Department of Neuroscience and Experimental Therapeutics, Albany Medical College, Albany, NY (T.R., M.D., J.P.); Edmond J. Safra Program in Parkinson's Disease, Morton and Gloria Shulman Movement Disorders Clinic, Toronto Western Hospital, UHN, Division of Neurology, University of Toronto, Toronto, Ontario, Canada (I.H., V.P., S.P., R.M., D.S., A.F.); GE Global Research Center, Niskayuna, NY (E.F.); Krembil Brain Institute, Toronto, Canada (A.F.); and Department of Neurosurgery, Albany Medical Center, Albany, NY (J.P.)
| | - Andres M Lozano
- From the Joint Department of Medical Imaging, University of Toronto, Toronto, Canada (A.B., A.C., W.K.); Division of Neurosurgery, Toronto Western Hospital, University Health Network, 399 Bathurst St, WW 4-437, Toronto, ON, Canada M5T 2S8 (A.B., G.J.B.E., R.M.G., J.G., B.L., V.P., S.P., M.R., A.C., D.G., C.T.C., R.M., D.S., M.H., S.K.K., A.F., W.K., A.M.L.); Department of Neuroscience and Experimental Therapeutics, Albany Medical College, Albany, NY (T.R., M.D., J.P.); Edmond J. Safra Program in Parkinson's Disease, Morton and Gloria Shulman Movement Disorders Clinic, Toronto Western Hospital, UHN, Division of Neurology, University of Toronto, Toronto, Ontario, Canada (I.H., V.P., S.P., R.M., D.S., A.F.); GE Global Research Center, Niskayuna, NY (E.F.); Krembil Brain Institute, Toronto, Canada (A.F.); and Department of Neurosurgery, Albany Medical Center, Albany, NY (J.P.)
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Ye H, Kaszuba S. Neuromodulation with electromagnetic stimulation for seizure suppression: From electrode to magnetic coil. IBRO Rep 2019; 7:26-33. [PMID: 31360792 PMCID: PMC6639724 DOI: 10.1016/j.ibror.2019.06.001] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2019] [Accepted: 06/25/2019] [Indexed: 12/31/2022] Open
Abstract
Non-invasive brain tissue stimulation with a magnetic coil provides several irreplaceable advantages over that with an implanted electrode, in altering neural activities under pathological situations. We reviewed clinical cases that utilized time-varying magnetic fields for the treatment of epilepsy, and the safety issues related to this practice. Animal models have been developed to foster understanding of the cellular/molecular mechanisms underlying magnetic control of epileptic activity. These mechanisms include (but are not limited to) (1) direct membrane polarization by the magnetic field, (2) depolarization blockade by the deactivation of ion channels, (3) alteration in synaptic transmission, and (4) interruption of ephaptic interaction and cellular synchronization. Clinical translation of this technology could be improved through the advancement of magnetic design, optimization of stimulation protocols, and evaluation of the long-term safety. Cellular and molecular studies focusing on the mechanisms of magnetic stimulation are of great value in facilitating this translation.
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Key Words
- 4-AP, 4-aminopyridine
- Animal models
- CD50, convulsant dose
- Cellular mechanisms
- DBS, deep brain stimulation
- EEG, electroencephalography
- ELF-MF, extremely low frequency magnetic fields
- EcoG, electrocorticography
- Epilepsy
- GABA, gamma-aminobutyric acid
- HFS, high frequency stimulation
- KA, kainic acid
- LD50, lethal dose
- LTD, long-term depression
- LTP, long-term potential
- MEG, magnetoencephalography
- MRI, magnetic resonance imaging
- Magnetic stimulation
- NMDAR, N-methyl-d-aspartate receptor
- PTZ, pentylenetetrazol
- REM, rapid eye movement
- SMF, static magnetic field
- TES, transcranial electrical stimulation
- TLE, temporal lobe epilepsy
- TMS, transcranial magnetic stimulation
- rTMS, repetitive transcranial magnetic stimulation
- tDCS, transcranial direct-current stimulation
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Affiliation(s)
- Hui Ye
- Department of Biology, Loyola University Chicago, Chicago, 1032 W. Sheridan Rd., IL, 60660, United States
| | - Stephanie Kaszuba
- Chicago Medical School, Rosalind Franklin University of Medicine and Science, 3333 Green Bay Rd., North Chicago, IL, 60064, United States
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Reconfigurable MRI technology for low-SAR imaging of deep brain stimulation at 3T: Application in bilateral leads, fully-implanted systems, and surgically modified lead trajectories. Neuroimage 2019; 199:18-29. [PMID: 31096058 DOI: 10.1016/j.neuroimage.2019.05.015] [Citation(s) in RCA: 40] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2019] [Revised: 04/24/2019] [Accepted: 05/06/2019] [Indexed: 11/22/2022] Open
Abstract
Patients with deep brain stimulation devices highly benefit from postoperative MRI exams, however MRI is not readily accessible to these patients due to safety risks associated with RF heating of the implants. Recently we introduced a patient-adjustable reconfigurable coil technology that substantially reduced local SAR at tips of single isolated DBS leads during MRI at 1.5 T in 9 realistic patient models. This contribution extends our work to higher fields by demonstrating the feasibility of scaling the technology to 3T and assessing its performance in patients with bilateral leads as well as fully implanted systems. We developed patient-derived models of bilateral DBS leads and fully implanted DBS systems from postoperative CT images of 13 patients and performed finite element simulations to calculate SAR amplification at electrode contacts during MRI with a reconfigurable rotating coil at 3T. Compared to a conventional quadrature body coil, the reconfigurable coil system reduced the SAR on average by 83% for unilateral leads and by 59% for bilateral leads. A simple surgical modification in trajectory of implanted leads was demonstrated to increase the SAR reduction efficiency of the rotating coil to >90% in a patient with a fully implanted bilateral DBS system. Thermal analysis of temperature-rise around electrode contacts during typical brain exams showed a 15-fold heating reduction using the rotating coil, generating <1°C temperature rise during ∼4-min imaging with high-SAR sequences where a conventional CP coil generated >10°C temperature rise in the tissue for the same flip angle.
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Prezelj N, Trošt M, Georgiev D, Flisar D. Lightning may pose a danger to patients receiving deep brain stimulation: case report. J Neurosurg 2019; 130:763-765. [PMID: 29712499 DOI: 10.3171/2017.12.jns172258] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2017] [Accepted: 12/11/2017] [Indexed: 11/06/2022]
Abstract
Deep brain stimulation (DBS) is an established treatment option for advanced stages of Parkinson's disease and other movement disorders. It is known that DBS is susceptible to strong electromagnetic fields (EMFs) that can be generated by various electrical devices at work, home, and in medical environments. EMFs can interfere with the proper functioning of implantable pulse generators (IPGs). Very strong EMFs can generate induction currents in implanted electrodes and even damage the brain. Manufacturers of DBS devices have issued a list of warnings on how to avoid this danger.Strong EMFs can result from natural forces as well. The authors present the case of a 66-year-old woman who was being treated with a rechargeable DBS system for neck dystonia when her apartment was struck by lightning. Domestic electronic devices that were operating during the event were burned and destroyed. The woman's IPG switched off but remained undamaged, and she suffered no neurological consequences.
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Affiliation(s)
- Neža Prezelj
- 1Department of Neurology, University Medical Centre Ljubljana; and
| | - Maja Trošt
- 1Department of Neurology, University Medical Centre Ljubljana; and
- 2Faculty of Medicine, University of Ljubljana, Slovenia
| | - Dejan Georgiev
- 1Department of Neurology, University Medical Centre Ljubljana; and
| | - Dušan Flisar
- 1Department of Neurology, University Medical Centre Ljubljana; and
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McElcheran CE, Golestanirad L, Iacono MI, Wei PS, Yang B, Anderson KJT, Bonmassar G, Graham SJ. Numerical Simulations of Realistic Lead Trajectories and an Experimental Verification Support the Efficacy of Parallel Radiofrequency Transmission to Reduce Heating of Deep Brain Stimulation Implants during MRI. Sci Rep 2019; 9:2124. [PMID: 30765724 PMCID: PMC6375985 DOI: 10.1038/s41598-018-38099-w] [Citation(s) in RCA: 37] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2018] [Accepted: 12/11/2018] [Indexed: 12/12/2022] Open
Abstract
Patients with deep brain stimulation (DBS) implants may be subject to heating during MRI due to interaction with excitatory radiofrequency (RF) fields. Parallel RF transmit (pTx) has been proposed to minimize such RF-induced heating in preliminary proof-of-concept studies. The present work evaluates the efficacy of pTx technique on realistic lead trajectories obtained from nine DBS patients. Electromagnetic simulations were performed using 4- and 8-element pTx coils compared with a standard birdcage coil excitation using patient models and lead trajectories obtained by segmentation of computed tomography data. Numerical optimization was performed to minimize local specific absorption rate (SAR) surrounding the implant tip while maintaining spatial homogeneity of the transmitted RF magnetic field (B1+), by varying the input amplitude and phase for each coil element. Local SAR was significantly reduced at the lead tip with both 4-element and 8-element pTx (median decrease of 94% and 97%, respectively), whereas the median coefficient of spatial variation of B1+ inhomogeneity was moderately increased (30% for 4-element pTx and 20% for 8-element pTx) compared to that of the birdcage coil (17%). Furthermore, the efficacy of optimized 4-element pTx was verified experimentally by imaging a head phantom that included a wire implanted to approximate the worst-case lead trajectory for localized heating, based on the simulations. Negligible temperature elevation was observed at the lead tip, with reasonable image uniformity in the surrounding region. From this experiment and the simulations based on nine DBS patient models, optimized pTx provides a robust approach to minimizing local SAR with respect to lead trajectory.
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Affiliation(s)
- C E McElcheran
- Physical Sciences Platform, Sunnybrook Health Sciences Institute, Toronto, Ontario, M4N 3M5, Canada
- Department of Medical Biophysics, University of Toronto, Toronto, Ontario, M5S 1A8, Canada
| | - L Golestanirad
- Department of Biomedical Engineering, Northwestern University, Evanston, IL, 60208, USA
| | - M I Iacono
- Division of Biomedical Physic, Office of Science and Engineering Laboratories, Center for Devices and Radiological Health, U.S Food and Drug Administration, Silver Spring, MD, 20993, USA
| | - P-S Wei
- Physical Sciences Platform, Sunnybrook Health Sciences Institute, Toronto, Ontario, M4N 3M5, Canada
| | - B Yang
- Physical Sciences Platform, Sunnybrook Health Sciences Institute, Toronto, Ontario, M4N 3M5, Canada
| | - K J T Anderson
- Physical Sciences Platform, Sunnybrook Health Sciences Institute, Toronto, Ontario, M4N 3M5, Canada
| | - G Bonmassar
- Athinoula A. Martinos Center For Biomedical Imaging, Department of Radiology, Massachusetts General Hospital, Charlestown, MA, 02129, USA
- Harvard Medical School, Boston, MA, 02115, USA
| | - S J Graham
- Physical Sciences Platform, Sunnybrook Health Sciences Institute, Toronto, Ontario, M4N 3M5, Canada.
- Department of Medical Biophysics, University of Toronto, Toronto, Ontario, M5S 1A8, Canada.
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McElcheran CE, Golestanirad L, Iacono MI, Wei PS, Yang B, Anderson KJT, Bonmassar G, Graham SJ. Numerical Simulations of Realistic Lead Trajectories and an Experimental Verification Support the Efficacy of Parallel Radiofrequency Transmission to Reduce Heating of Deep Brain Stimulation Implants during MRI. Sci Rep 2019. [PMID: 30765724 DOI: 10.1038/s41598-01838099-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/06/2023] Open
Abstract
Patients with deep brain stimulation (DBS) implants may be subject to heating during MRI due to interaction with excitatory radiofrequency (RF) fields. Parallel RF transmit (pTx) has been proposed to minimize such RF-induced heating in preliminary proof-of-concept studies. The present work evaluates the efficacy of pTx technique on realistic lead trajectories obtained from nine DBS patients. Electromagnetic simulations were performed using 4- and 8-element pTx coils compared with a standard birdcage coil excitation using patient models and lead trajectories obtained by segmentation of computed tomography data. Numerical optimization was performed to minimize local specific absorption rate (SAR) surrounding the implant tip while maintaining spatial homogeneity of the transmitted RF magnetic field (B1+), by varying the input amplitude and phase for each coil element. Local SAR was significantly reduced at the lead tip with both 4-element and 8-element pTx (median decrease of 94% and 97%, respectively), whereas the median coefficient of spatial variation of B1+ inhomogeneity was moderately increased (30% for 4-element pTx and 20% for 8-element pTx) compared to that of the birdcage coil (17%). Furthermore, the efficacy of optimized 4-element pTx was verified experimentally by imaging a head phantom that included a wire implanted to approximate the worst-case lead trajectory for localized heating, based on the simulations. Negligible temperature elevation was observed at the lead tip, with reasonable image uniformity in the surrounding region. From this experiment and the simulations based on nine DBS patient models, optimized pTx provides a robust approach to minimizing local SAR with respect to lead trajectory.
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Affiliation(s)
- C E McElcheran
- Physical Sciences Platform, Sunnybrook Health Sciences Institute, Toronto, Ontario, M4N 3M5, Canada
- Department of Medical Biophysics, University of Toronto, Toronto, Ontario, M5S 1A8, Canada
| | - L Golestanirad
- Department of Biomedical Engineering, Northwestern University, Evanston, IL, 60208, USA
| | - M I Iacono
- Division of Biomedical Physic, Office of Science and Engineering Laboratories, Center for Devices and Radiological Health, U.S Food and Drug Administration, Silver Spring, MD, 20993, USA
| | - P-S Wei
- Physical Sciences Platform, Sunnybrook Health Sciences Institute, Toronto, Ontario, M4N 3M5, Canada
| | - B Yang
- Physical Sciences Platform, Sunnybrook Health Sciences Institute, Toronto, Ontario, M4N 3M5, Canada
| | - K J T Anderson
- Physical Sciences Platform, Sunnybrook Health Sciences Institute, Toronto, Ontario, M4N 3M5, Canada
| | - G Bonmassar
- Athinoula A. Martinos Center For Biomedical Imaging, Department of Radiology, Massachusetts General Hospital, Charlestown, MA, 02129, USA
- Harvard Medical School, Boston, MA, 02115, USA
| | - S J Graham
- Physical Sciences Platform, Sunnybrook Health Sciences Institute, Toronto, Ontario, M4N 3M5, Canada.
- Department of Medical Biophysics, University of Toronto, Toronto, Ontario, M5S 1A8, Canada.
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Iacono MI, Atefi SR, Mainardi L, Walker HC, Angelone LM, Bonmassar G. A Study on the Feasibility of the Deep Brain Stimulation (DBS) Electrode Localization Based on Scalp Electric Potential Recordings. Front Physiol 2019; 9:1788. [PMID: 30662407 PMCID: PMC6328462 DOI: 10.3389/fphys.2018.01788] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2018] [Accepted: 11/28/2018] [Indexed: 11/13/2022] Open
Abstract
Deep Brain Stimulation (DBS) is an effective therapy for patients disabling motor symptoms from Parkinson's disease, essential tremor, and other motor disorders. Precise, individualized placement of DBS electrodes is a key contributor to clinical outcomes following surgery. Electroencephalography (EEG) is widely used to identify the sources of intracerebral signals from the potential on the scalp. EEG is portable, non-invasive, low-cost, and it could be easily integrated into the intraoperative or ambulatory environment for localization of either the DBS electrode or evoked potentials triggered by stimulation itself. In this work, we studied with numerical simulations the principle of extracting the DBS electrical pulse from the patient's EEG - which normally constitutes an artifact - and localizing the source of the artifact (i.e., the DBS electrodes) using EEG localization methods. A high-resolution electromagnetic head model was used to simulate the EEG potential at the scalp generated by the DBS pulse artifact. The potential distribution on the scalp was then sampled at the 256 electrode locations of a high-density EEG Net. The electric potential was modeled by a dipole source created by a given pair of active DBS electrodes. The dynamic Statistical Parametric Maps (dSPM) algorithm was used to solve the EEG inverse problem, and it allowed localization of the position of the stimulus dipole in three DBS electrode bipolar configurations with a maximum error of 1.5 cm. To assess the accuracy of the computational model, the results of the simulation were compared with the electric artifact amplitudes over 16 EEG electrodes measured in five patients. EEG artifacts measured in patients confirmed that simulated data are commensurate to patients' data (0 ± 6.6 μV). While we acknowledge that further work is necessary to achieve a higher accuracy needed for surgical navigation, the results presented in this study are proposed as the first step toward a validated computational framework that could be used for non-invasive localization not only of the DBS system but also brain rhythms triggered by stimulation at both proximal and distal sites in the human central nervous system.
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Affiliation(s)
- Maria Ida Iacono
- Athinoula A. Martinos Center for Biomedical Imaging, Department of Radiology, Massachusetts General Hospital, Harvard Medical School, Charlestown, MA, United States.,Division of Biomedical Physics, Office of Science and Engineering Laboratories, Center for Devices and Radiological Health, U.S. Food and Drug Administration, Silver Spring, MD, United States
| | - Seyed Reza Atefi
- Athinoula A. Martinos Center for Biomedical Imaging, Department of Radiology, Massachusetts General Hospital, Harvard Medical School, Charlestown, MA, United States
| | - Luca Mainardi
- Bioengineering Department, Politecnico di Milano, Milan, Italy
| | - Harrison C Walker
- Department of Neurology, University of Alabama at Birmingham, Birmingham, AL, United States.,Division of Movement Disorders, University of Alabama at Birmingham, Birmingham, AL, United States
| | - Leonardo M Angelone
- Division of Biomedical Physics, Office of Science and Engineering Laboratories, Center for Devices and Radiological Health, U.S. Food and Drug Administration, Silver Spring, MD, United States
| | - Giorgio Bonmassar
- Athinoula A. Martinos Center for Biomedical Imaging, Department of Radiology, Massachusetts General Hospital, Harvard Medical School, Charlestown, MA, United States
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Kilbane C, Witt J, Galifianakis N, Glass G, Volz M, Heath S, Starr P, Ostrem J. Long-Term Outcomes of Bilateral Pallidal Deep Brain Stimulation for X-Linked Dystonia and Parkinsonism. Stereotact Funct Neurosurg 2018; 96:320-326. [DOI: 10.1159/000492823] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2018] [Accepted: 08/09/2018] [Indexed: 11/19/2022]
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Fečíková A, Jech R, Čejka V, Čapek V, Šťastná D, Štětkářová I, Mueller K, Schroeter ML, Růžička F, Urgošík D. Benefits of pallidal stimulation in dystonia are linked to cerebellar volume and cortical inhibition. Sci Rep 2018; 8:17218. [PMID: 30464181 PMCID: PMC6249276 DOI: 10.1038/s41598-018-34880-z] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2018] [Accepted: 10/26/2018] [Indexed: 11/18/2022] Open
Abstract
Clinical benefits of pallidal deep brain stimulation (GPi DBS) in dystonia increase relatively slowly suggesting slow plastic processes in the motor network. Twenty-two patients with dystonia of various distribution and etiology treated by chronic GPi DBS and 22 healthy subjects were examined for short-latency intracortical inhibition of the motor cortex elicited by paired transcranial magnetic stimulation. The relationships between grey matter volume and intracortical inhibition considering the long-term clinical outcome and states of the GPi DBS were analysed. The acute effects of GPi DBS were associated with a shortening of the motor response whereas the grey matter of chronically treated patients with a better clinical outcome showed hypertrophy of the supplementary motor area and cerebellar vermis. In addition, the volume of the cerebellar hemispheres of patients correlated with the improvement of intracortical inhibition which was generally less effective in patients than in controls regardless of the DBS states. Importantly, good responders to GPi DBS showed a similar level of short-latency intracortical inhibition in the motor cortex as healthy controls whereas non-responders were unable to increase it. All these results support the multilevel impact of effective DBS on the motor networks in dystonia and suggest potential biomarkers of responsiveness to this treatment.
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Affiliation(s)
- Anna Fečíková
- Department of Neurology and Centre of Clinical Neuroscience, First Faculty of Medicine and General University Hospital, Charles University, Prague, Czech Republic
| | - Robert Jech
- Department of Neurology and Centre of Clinical Neuroscience, First Faculty of Medicine and General University Hospital, Charles University, Prague, Czech Republic.
| | - Václav Čejka
- Department of Neurology and Centre of Clinical Neuroscience, First Faculty of Medicine and General University Hospital, Charles University, Prague, Czech Republic.,Faculty of Biomedical Engineering, Czech Technical University in Prague, Prague, Czech Republic
| | - Václav Čapek
- Department of Neurology and Centre of Clinical Neuroscience, First Faculty of Medicine and General University Hospital, Charles University, Prague, Czech Republic
| | - Daniela Šťastná
- Department of Neurosurgery, Na Homolce Hospital, Prague, Czech Republic
| | - Ivana Štětkářová
- Department of Neurology, Third Faculty of Medicine, Charles University and Faculty Hospital Kralovske Vinohrady, Prague, Czech Republic
| | - Karsten Mueller
- Max Planck Institute for Human Cognitive and Brain Sciences, Leipzig, Germany
| | - Matthias L Schroeter
- Max Planck Institute for Human Cognitive and Brain Sciences, Leipzig, Germany.,Clinic for Cognitive Neurology, University Hospital, Leipzig, Germany
| | - Filip Růžička
- Department of Neurology and Centre of Clinical Neuroscience, First Faculty of Medicine and General University Hospital, Charles University, Prague, Czech Republic
| | - Dušan Urgošík
- Department of Stereotactic and Radiation Neurosurgery, Na Homolce Hospital, Prague, Czech Republic
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RF-induced heating in tissue near bilateral DBS implants during MRI at 1.5 T and 3T: The role of surgical lead management. Neuroimage 2018; 184:566-576. [PMID: 30243973 DOI: 10.1016/j.neuroimage.2018.09.034] [Citation(s) in RCA: 62] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2018] [Revised: 09/10/2018] [Accepted: 09/14/2018] [Indexed: 11/21/2022] Open
Abstract
Access to MRI is limited for patients with deep brain stimulation (DBS) implants due to safety hazards, including radiofrequency (RF) heating of tissue surrounding the leads. Computational models provide an exquisite tool to explore the multi-variate problem of RF heating and help better understand the interaction of electromagnetic fields and biological tissues. This paper presents a computational approach to assess RF-induced heating, in terms of specific absorption rate (SAR) in the tissue, around the tip of bilateral DBS leads during MRI at 64MHz/1.5 T and 127 MHz/3T. Patient-specific realistic lead models were constructed from post-operative CT images of nine patients operated for sub-thalamic nucleus DBS. Finite element method was applied to calculate the SAR at the tip of left and right DBS contact electrodes. Both transmit head coils and transmit body coils were analyzed. We found a substantial difference between the SAR and temperature rise at the tip of right and left DBS leads, with the lead contralateral to the implanted pulse generator (IPG) exhibiting up to 7 times higher SAR in simulations, and up to 10 times higher temperature rise during measurements. The orientation of incident electric field with respect to lead trajectories was explored and a metric to predict local SAR amplification was introduced. Modification of the lead trajectory was shown to substantially reduce the heating in phantom experiments using both conductive wires and commercially available DBS leads. Finally, the surgical feasibility of implementing the modified trajectories was demonstrated in a patient operated for bilateral DBS.
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Lio G, Thobois S, Ballanger B, Lau B, Boulinguez P. Removing deep brain stimulation artifacts from the electroencephalogram: Issues, recommendations and an open-source toolbox. Clin Neurophysiol 2018; 129:2170-2185. [PMID: 30144660 DOI: 10.1016/j.clinph.2018.07.023] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2014] [Revised: 07/23/2018] [Accepted: 07/28/2018] [Indexed: 12/30/2022]
Abstract
A major question for deep brain stimulation (DBS) research is understanding how DBS of one target area modulates activity in different parts of the brain. EEG gives privileged access to brain dynamics, but its use with implanted patients is limited since DBS adds significant high-amplitude electrical artifacts that can completely obscure neural activity measured using EEG. Here, we systematically review and discuss the methods available for removing DBS artifacts. These include simple techniques such as oversampling, antialiasing analog filtering and digital low-pass filtering, which are necessary but typically not sufficient to fully remove DBS artifacts when each is used in isolation. We also cover more advanced methods, including techniques tracking outliers in the frequency-domain, which can be effective, but are rarely used. The reason for that is twofold: First, it requires advanced skills in signal processing since no user friendly tool for removing DBS artifacts is currently available. Second, it involves fine-tuning to avoid over-aggressive filtering. We highlight an open-source toolbox incorporating most artifact removal methods, allowing users to combine different strategies.
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Affiliation(s)
- Guillaume Lio
- Université de Lyon, F-69622 Lyon, France; Université Lyon 1, Villeurbanne, France; CNRS, Centre de Neuroscience Cognitive, Bron, France
| | - Stéphane Thobois
- Université de Lyon, F-69622 Lyon, France; Université Lyon 1, Villeurbanne, France; CNRS, Centre de Neuroscience Cognitive, Bron, France; Hospices civils de Lyon, hôpital neurologique Pierre Wertheimer, Bron, France
| | - Bénédicte Ballanger
- Université de Lyon, F-69622 Lyon, France; Université Lyon 1, Villeurbanne, France; INSERM U1028, CNRS UMR5292, Centre de Recherche en Neurosciences de Lyon, Lyon, France
| | - Brian Lau
- Sorbonne Universités, UPMC Univ Paris 06, UMR S 1127, CNRS UMR 7225, Institut du Cerveau et de la Moelle épinière, F-75013 Paris, France
| | - Philippe Boulinguez
- Université de Lyon, F-69622 Lyon, France; Université Lyon 1, Villeurbanne, France; INSERM U1028, CNRS UMR5292, Centre de Recherche en Neurosciences de Lyon, Lyon, France.
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Rusz J, Tykalová T, Fečíková A, Šťastná D, Urgošík D, Jech R. Dualistic effect of pallidal deep brain stimulation on motor speech disorders in dystonia. Brain Stimul 2018; 11:896-903. [DOI: 10.1016/j.brs.2018.03.007] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2017] [Revised: 01/24/2018] [Accepted: 03/09/2018] [Indexed: 10/17/2022] Open
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Golestanirad L, Rahsepar AA, Kirsch JE, Suwa K, Collins JC, Angelone LM, Keil B, Passman RS, Bonmassar G, Serano P, Krenz P, DeLap J, Carr JC, Wald LL. Changes in the specific absorption rate (SAR) of radiofrequency energy in patients with retained cardiac leads during MRI at 1.5T and 3T. Magn Reson Med 2018; 81:653-669. [PMID: 29893997 PMCID: PMC6258273 DOI: 10.1002/mrm.27350] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2017] [Revised: 04/08/2018] [Accepted: 04/16/2018] [Indexed: 12/20/2022]
Abstract
PURPOSE To evaluate the local specific absorption rate (SAR) and heating around retained cardiac leads during MRI at 64 MHz (1.5T) and 127 MHz (3T) as a function of RF coil type and imaging landmark. METHODS Numerical models of retained cardiac leads were built from CT and X-ray images of 6 patients with retained cardiac leads. Electromagnetic simulations and bio-heat modeling were performed with MRI RF body and head coils tuned to 64 MHz and 127 MHz and positioned at 9 different imaging landmarks covering an area from the head to the lower limbs. RESULTS For all patients and at both 1.5T and 3T, local transmit head coils produced negligible temperature rise ( <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:mrow><mml:mo>Δ</mml:mo> <mml:mi>T</mml:mi> <mml:mo><</mml:mo> <mml:mn>0.1</mml:mn> <mml:mo>°</mml:mo> <mml:mi>C</mml:mi></mml:mrow> </mml:math> ) for <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:mrow><mml:mrow><mml:mo>‖</mml:mo> <mml:mo>‖</mml:mo> <mml:mrow><mml:msubsup><mml:mi>B</mml:mi> <mml:mn>1</mml:mn> <mml:mo>+</mml:mo></mml:msubsup> </mml:mrow> <mml:mo>‖</mml:mo> <mml:mo>‖</mml:mo></mml:mrow> <mml:mo>≤</mml:mo> <mml:mn>3</mml:mn> <mml:mo> </mml:mo> <mml:mo>μ</mml:mo> <mml:mi>T</mml:mi></mml:mrow> </mml:math> . For body imaging with quadrature-driven coils at 1.5T, <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:mrow><mml:mo>Δ</mml:mo> <mml:mi>T</mml:mi></mml:mrow> </mml:math> during a 10-min scan remained < 3°C at all imaging landmarks for <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:mrow><mml:mrow><mml:mo>‖</mml:mo> <mml:mo>‖</mml:mo> <mml:mrow><mml:msubsup><mml:mi>B</mml:mi> <mml:mn>1</mml:mn> <mml:mo>+</mml:mo></mml:msubsup> </mml:mrow> <mml:mo>‖</mml:mo> <mml:mo>‖</mml:mo></mml:mrow> <mml:mo>≤</mml:mo> <mml:mn>3</mml:mn> <mml:mo> </mml:mo> <mml:mo>μ</mml:mo> <mml:mi>T</mml:mi></mml:mrow> </mml:math> and <6°C for <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:mrow><mml:mrow><mml:mo>‖</mml:mo> <mml:mo>‖</mml:mo> <mml:mrow><mml:msubsup><mml:mi>B</mml:mi> <mml:mn>1</mml:mn> <mml:mo>+</mml:mo></mml:msubsup> </mml:mrow> <mml:mo>‖</mml:mo> <mml:mo>‖</mml:mo></mml:mrow> <mml:mo>≤</mml:mo> <mml:mn>4</mml:mn> <mml:mo> </mml:mo> <mml:mo>μ</mml:mo> <mml:mi>T</mml:mi></mml:mrow> </mml:math> . For body imaging at 3T, <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:mrow><mml:mo>Δ</mml:mo> <mml:mi>T</mml:mi></mml:mrow> </mml:math> during a 10-min scan remained < 6°C at all imaging landmarks for <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:mrow><mml:mrow><mml:mo>‖</mml:mo> <mml:mo>‖</mml:mo> <mml:mrow><mml:msubsup><mml:mi>B</mml:mi> <mml:mn>1</mml:mn> <mml:mo>+</mml:mo></mml:msubsup> </mml:mrow> <mml:mo>‖</mml:mo> <mml:mo>‖</mml:mo></mml:mrow> <mml:mo>≤</mml:mo> <mml:mn>2</mml:mn> <mml:mo> </mml:mo> <mml:mo>μ</mml:mo> <mml:mi>T</mml:mi></mml:mrow> </mml:math> . For shorter pulse sequences up to 2 min, <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:mrow><mml:mo>Δ</mml:mo> <mml:mi>T</mml:mi></mml:mrow> </mml:math> remained < 6°C for <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:mrow><mml:mrow><mml:mo>‖</mml:mo> <mml:mo>‖</mml:mo> <mml:mrow><mml:msubsup><mml:mi>B</mml:mi> <mml:mn>1</mml:mn> <mml:mo>+</mml:mo></mml:msubsup> </mml:mrow> <mml:mo>‖</mml:mo> <mml:mo>‖</mml:mo></mml:mrow> <mml:mo>≤</mml:mo> <mml:mn>3</mml:mn> <mml:mo> </mml:mo> <mml:mo>μ</mml:mo> <mml:mi>T</mml:mi></mml:mrow> </mml:math> . CONCLUSION For the models based on 6 patients studied, simulations suggest that MRI could be performed safely using a local head coil at both 1.5T and 3T, and with a body coil at 1.5T with pulses that produced <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:mrow><mml:mrow><mml:mo>‖</mml:mo> <mml:mo>‖</mml:mo> <mml:mrow><mml:msubsup><mml:mi>B</mml:mi> <mml:mn>1</mml:mn> <mml:mo>+</mml:mo></mml:msubsup> </mml:mrow> <mml:mo>‖</mml:mo> <mml:mo>‖</mml:mo></mml:mrow> <mml:mo>≤</mml:mo> <mml:mn>4</mml:mn> <mml:mo> </mml:mo> <mml:mo>μ</mml:mo> <mml:mi>T</mml:mi></mml:mrow> </mml:math> . MRI at 3T could be performed safely in these patients using pulses with <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:mrow><mml:mrow><mml:mo>‖</mml:mo> <mml:mo>‖</mml:mo> <mml:mrow><mml:msubsup><mml:mi>B</mml:mi> <mml:mn>1</mml:mn> <mml:mo>+</mml:mo></mml:msubsup> </mml:mrow> <mml:mo>‖</mml:mo> <mml:mo>‖</mml:mo></mml:mrow> <mml:mo>≤</mml:mo> <mml:mn>2</mml:mn> <mml:mo> </mml:mo> <mml:mo>μ</mml:mo> <mml:mi>T</mml:mi></mml:mrow> </mml:math> .
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Affiliation(s)
- Laleh Golestanirad
- Athinoula A. Martinos Center for Biomedical Imaging, Department of Radiology, Massachusetts General Hospital, Harvard Medical School, Charlestown, Massachusetts.,Department of Radiology, Northwestern University, Feinberg School of Medicine, Chicago, Illinois
| | - Amir Ali Rahsepar
- Department of Radiology, Northwestern University, Feinberg School of Medicine, Chicago, Illinois
| | - John E Kirsch
- Athinoula A. Martinos Center for Biomedical Imaging, Department of Radiology, Massachusetts General Hospital, Harvard Medical School, Charlestown, Massachusetts
| | - Kenichiro Suwa
- Department of Radiology, Northwestern University, Feinberg School of Medicine, Chicago, Illinois
| | - Jeremy C Collins
- Department of Radiology, Northwestern University, Feinberg School of Medicine, Chicago, Illinois
| | - Leonardo M Angelone
- Division of Biomedical Physics, Office of Science and Engineering Laboratories, Center for Devices and Radiological Health, U.S. Food and Drug Administration, Silver Spring, Maryland
| | - Boris Keil
- Department of Life Science Engineering, Institute of Medical Physics and Radiation Protection, Giessen, Germany
| | - Rod S Passman
- Division of Cardiology, Department of Medicine, Northwestern University, Feinberg School of Medicine, Chicago, Illinois
| | - Giorgio Bonmassar
- Athinoula A. Martinos Center for Biomedical Imaging, Department of Radiology, Massachusetts General Hospital, Harvard Medical School, Charlestown, Massachusetts
| | - Peter Serano
- Division of Biomedical Physics, Office of Science and Engineering Laboratories, Center for Devices and Radiological Health, U.S. Food and Drug Administration, Silver Spring, Maryland
| | | | - Jim DeLap
- ANSYS Inc., Canonsburg, Pennsylvania
| | - James C Carr
- Department of Radiology, Northwestern University, Feinberg School of Medicine, Chicago, Illinois
| | - Lawrence L Wald
- Athinoula A. Martinos Center for Biomedical Imaging, Department of Radiology, Massachusetts General Hospital, Harvard Medical School, Charlestown, Massachusetts
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Brain connectivity changes when comparing effects of subthalamic deep brain stimulation with levodopa treatment in Parkinson's disease. NEUROIMAGE-CLINICAL 2018; 19:1025-1035. [PMID: 30035027 PMCID: PMC6051673 DOI: 10.1016/j.nicl.2018.05.006] [Citation(s) in RCA: 34] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/30/2017] [Revised: 04/27/2018] [Accepted: 05/08/2018] [Indexed: 11/22/2022]
Abstract
Levodopa and, later, deep brain stimulation (DBS) have become the mainstays of therapy for motor symptoms associated with Parkinson's disease (PD). Although these therapeutic options lead to similar clinical outcomes, the neural mechanisms underlying their efficacy are different. Therefore, investigating the differential effects of DBS and levodopa on functional brain architecture and associated motor improvement is of paramount interest. Namely, we expected changes in functional brain connectivity patterns when comparing levodopa treatment with DBS. Clinical assessment and functional magnetic resonance imaging (fMRI) was performed before and after implanting electrodes for DBS in the subthalamic nucleus (STN) in 13 PD patients suffering from severe levodopa-induced motor fluctuations and peak-of-dose dyskinesia. All measurements were acquired in a within subject-design with and without levodopa treatment, and with and without DBS. Brain connectivity changes were computed using eigenvector centrality (EC) that offers a data-driven and parameter-free approach—similarly to Google's PageRank algorithm—revealing brain regions that have an increased connectivity to other regions that are highly connected, too. Both levodopa and DBS led to comparable improvement of motor symptoms as measured with the Unified Parkinson's Disease Rating Scale motor score (UPDRS-III). However, this similar therapeutic effect was underpinned by different connectivity modulations within the motor system. In particular, EC revealed a major increase of interconnectedness in the left and right motor cortex when comparing DBS to levodopa. This was accompanied by an increase of connectivity of these motor hubs with the thalamus and cerebellum. We observed, for the first time, significant functional connectivity changes when comparing the effects of STN DBS and oral levodopa administration, revealing different treatment-specific mechanisms linked to clinical benefit in PD. Specifically, in contrast to levodopa treatment, STN DBS was associated with increased connectivity within the cortico-thalamo-cerebellar network. Moreover, given the favorable effects of STN DBS on motor complications, the changes in the patients' clinical profile might also contribute to connectivity changes associated with STN-DBS. Understanding the observed connectivity changes may be essential for enhancing the effectiveness of DBS treatment, and for better defining the pathophysiology of the disrupted motor network in PD. Functional MRI was done before and after implanting DBS electrodes in same patients. Impacts of DBS and levodopa administration on brain motor circuitry are different. Comparison between DBS and levodopa treatment shows a major connectivity increase. Treatment related connectivity changes can be disentangled from electrode implantation.
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Li JJ, Shi L, Chen YC, Zhu GY, Zhang JG. Ultrahigh-Magnitude Brain Magnetic Resonance Imaging Scan on Rhesus Monkeys With Implanted Deep Brain Stimulation Hardware. Neuromodulation 2017; 21:168-175. [PMID: 29219219 DOI: 10.1111/ner.12735] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2017] [Accepted: 10/13/2017] [Indexed: 11/26/2022]
Abstract
BACKGROUND Patients with implanted deep brain stimulation (DBS) hardware are prohibited from undergoing magnetic resonance imaging (MRI) scans at magnitudes greater than 1.5 T to avoid potential MRI-related heating injury. Whether DBS devices are compatible with higher field MRI scanning is unknown. This study aimed to investigate whether 7.0 T and 3.0 T MRI scans can be safely performed on rhesus monkeys with implanted DBS devices. METHODS Eight male rhesus monkeys were included in this study and stereotactically implanted with DBS devices in the left anterior thalamus. Two weeks after DBS device implantation, 7.0 T and 3.0 T MRI scans were performed. The monkeys were observed for 72 hours. After explantation of the DBS system, 7.0 T MRI was repeated to determine potential lesions. Hematoxylin and eosin staining and transmission electron microscopy were conducted to assess pathological alterations. RESULTS In both groups, the monkeys exhibited no behavioral changes related to neurological deficits. Post-explantation MRI showed no malacia foci surrounding the DBS tracks. Additionally, neither hematoxylin and eosin staining nor transmission electron microscopy showed clear injury near the DBS leads. CONCLUSION These results indicate that no obvious heating injury was induced in the tissue surrounding the DBS leads by the 7.0 T and 3.0 T MRI scans. Although the results of this study may not be generalizable, these data suggest that patients with implanted DBS devices can undergo even 7.0 T MRI without risk of brain injury.
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Affiliation(s)
- Jun-Ju Li
- Department of Neurosurgery, Beijing Tiantan Hospital, Capital Medical University, Beijing, China.,Functional Neurosurgery Laboratory, Beijing Neurosurgical Institute, Beijing, China.,Department of Neurosurgery, People's Hospital of Hainan Province, Haikou, China
| | - Lin Shi
- Department of Neurosurgery, Beijing Tiantan Hospital, Capital Medical University, Beijing, China.,Functional Neurosurgery Laboratory, Beijing Neurosurgical Institute, Beijing, China
| | - Ying-Chuan Chen
- Department of Neurosurgery, Beijing Tiantan Hospital, Capital Medical University, Beijing, China.,Functional Neurosurgery Laboratory, Beijing Neurosurgical Institute, Beijing, China
| | - Guan-Yu Zhu
- Department of Neurosurgery, Beijing Tiantan Hospital, Capital Medical University, Beijing, China.,Functional Neurosurgery Laboratory, Beijing Neurosurgical Institute, Beijing, China
| | - Jian-Guo Zhang
- Department of Neurosurgery, Beijing Tiantan Hospital, Capital Medical University, Beijing, China.,Functional Neurosurgery Laboratory, Beijing Neurosurgical Institute, Beijing, China
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Xia J, He P, Cai X, Zhang D, Xie N. Magnetic resonance and computed tomography image fusion technology in patients with Parkinson's disease after deep brain stimulation. J Neurol Sci 2017; 381:250-255. [PMID: 28991693 DOI: 10.1016/j.jns.2017.08.3267] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2017] [Revised: 08/31/2017] [Accepted: 08/31/2017] [Indexed: 10/18/2022]
Abstract
Electrode position after deep brain stimulation (DBS) for Parkinson's disease (PD) needs to be confirmed, but there are concerns about the risk of postoperative magnetic resonance imaging (MRI) after DBS. These issues could be avoided by fusion images obtained from preoperative MRI and postoperative computed tomography (CT). This study aimed to investigate image fusion technology for displaying the position of the electrodes compared with postoperative MRI. This was a retrospective study of 32 patients with PD treated with bilateral subthalamic nucleus (STN) DBS between April 2015 and March 2016. The postoperative (same day) CT and preoperative MRI were fused using the Elekta Leksell 10.1 planning workstation (Elekta Instruments, Stockholm, Sweden). The position of the electrodes was compared between the fusion images and postoperative 1-2-week MRI. The position of the electrodes was highly correlated between the fusion and postoperative MRI (all r between 0.865 and 0.996; all P<0.001). The differences of the left electrode position in the lateral and vertical planes was significantly different between the two methods (0.30 and 0.24mm, respectively, both P<0.05), but there were no significant differences for the other electrode and planes (all P>0.05). The position of the electrodes was highly correlated between the fusion and postoperative MRI. The CT-MRI fusion images could be used to avoid the potential risks of MRI after DBS in patients with PD.
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Affiliation(s)
- Jun Xia
- Department of Radiology, Shenzhen Second People's Hospital (the First Affiliated Hospital of Shenzhen University), Shenzhen 518035, China
| | - Pin He
- Department of Radiology, Shenzhen Second People's Hospital (the First Affiliated Hospital of Shenzhen University), Shenzhen 518035, China
| | - Xiaodong Cai
- Department of Neurosurgery, Shenzhen Second People's Hospital (the First Affiliated Hospital of Shenzhen University), Shenzhen 518035, China
| | - Doudou Zhang
- Department of Neurosurgery, Shenzhen Second People's Hospital (the First Affiliated Hospital of Shenzhen University), Shenzhen 518035, China
| | - Ni Xie
- Central Laboratory, Shenzhen Second People's Hospital (the First Affiliated Hospital of Shenzhen University), Shenzhen 518035, China.
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Gilmore G, Lee DH, Parrent A, Jog M. The current state of postoperative imaging in the presence of deep brain stimulation electrodes. Mov Disord 2017; 32:833-838. [DOI: 10.1002/mds.27028] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2016] [Revised: 03/01/2017] [Accepted: 03/31/2017] [Indexed: 11/08/2022] Open
Affiliation(s)
- Greydon Gilmore
- Department of Biomedical Engineering; Western University; London Canada
- Department of Clinical Neurological Sciences; University Hospital; London Canada
| | - Donald H. Lee
- Department of Medical Imaging; University Hospital; London Canada
| | - Andrew Parrent
- Department of Clinical Neurological Sciences; University Hospital; London Canada
- Department of Neurosurgery; University Hospital; London Canada
| | - Mandar Jog
- Department of Biomedical Engineering; Western University; London Canada
- Department of Clinical Neurological Sciences; University Hospital; London Canada
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Nagy Z, Oliver-Taylor A, Kuehne A, Goluch S, Weiskopf N. Tx/Rx Head Coil Induces Less RF Transmit-Related Heating than Body Coil in Conductive Metallic Objects Outside the Active Area of the Head Coil. Front Neurosci 2017; 11:15. [PMID: 28184184 PMCID: PMC5266708 DOI: 10.3389/fnins.2017.00015] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2016] [Accepted: 01/09/2017] [Indexed: 11/25/2022] Open
Abstract
The transmit-receive (Tx/Rx) birdcage head coil is often used for excitation instead of the body coil because of the presumably lower risk of heating in and around conductive implants. However, this common practice has not been systematically tested. To investigate whether the Tx/Rx birdcage head coil produces less heating than the body coil when scanning individuals with implants, we used a 3T clinical scanner and made temperature measurements around a straight 15 cm conductor using either the Tx/Rx body or the head coil for excitation. Additionally, the transmitted fields of a Tx/Rx head coil were measured both in air and in gel using a resonant and a non-resonant B field probes as well as a non-resonant E field probe. Simulations using a finite-difference time domain solver were compared with the experimental findings. When the body coil was used for excitation, we observed heating around the 15 cm wire at various anatomical locations (both within and outside of the active volume of the head coil). Outside its active area, no such heating was observed while using the Tx/Rx head coil for excitation. The E and B fields of the Tx/Rx birdcage head coil extended well-beyond the physical dimensions of the coil. In air, the fields were monotonically decreasing, while in gel they were more complex with local maxima at the end of the ASTM phantom. These experimental findings were line with the simulations. While caution must always be exercised when scanning individuals with metallic implants, these findings support the use of the Tx/Rx birdcage head coil in place of the body coil at 3T in order to reduce the risk of heating in and around conductive implants that are remote from the head coil.
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Affiliation(s)
- Zoltan Nagy
- Laboratory for Social and Neural Systems Research, University of ZürichZürich, Switzerland
- Wellcome Trust Centre for Neuroimaging, University College LondonLondon, UK
| | - Aaron Oliver-Taylor
- Department of Neonatology, Institute for Women's Health, University College LondonLondon, UK
| | - Andre Kuehne
- Center for Medical Physics and Biomedical Engineering, Medical University of ViennaVienna, Austria
- MR Center of Excellence, Medical University of ViennaVienna, Austria
| | - Sigrun Goluch
- Center for Medical Physics and Biomedical Engineering, Medical University of ViennaVienna, Austria
- MR Center of Excellence, Medical University of ViennaVienna, Austria
| | - Nikolaus Weiskopf
- Wellcome Trust Centre for Neuroimaging, University College LondonLondon, UK
- Department of Neurophysics, Max Planck Institute for Human Cognitive and Brain SciencesLeipzig, Germany
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Yeoh TY, Manninen P, Kalia SK, Venkatraghavan L. Anesthesia considerations for patients with an implanted deep brain stimulator undergoing surgery: a review and update. Can J Anaesth 2016; 64:308-319. [DOI: 10.1007/s12630-016-0794-8] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2016] [Revised: 10/06/2016] [Accepted: 12/08/2016] [Indexed: 11/25/2022] Open
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Golestanirad L, Iacono MI, Keil B, Angelone LM, Bonmassar G, Fox MD, Herrington T, Adalsteinsson E, LaPierre C, Mareyam A, Wald LL. Construction and modeling of a reconfigurable MRI coil for lowering SAR in patients with deep brain stimulation implants. Neuroimage 2016; 147:577-588. [PMID: 28011252 DOI: 10.1016/j.neuroimage.2016.12.056] [Citation(s) in RCA: 42] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2016] [Revised: 11/13/2016] [Accepted: 12/19/2016] [Indexed: 10/20/2022] Open
Abstract
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.
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Affiliation(s)
- Laleh Golestanirad
- Athinoula A. Martinos Center for Biomedical Imaging, Department of Radiology, Massachusetts General Hospital, Boston, MA, USA; Harvard Medical School, Boston, MA, USA.
| | - Maria Ida Iacono
- Division of Biomedical Physics, Office of Science and Engineering Laboratories, Center for Devices and Radiological Health, US Food and Drug Administration, Silver Spring, MD, USA
| | - Boris Keil
- Athinoula A. Martinos Center for Biomedical Imaging, Department of Radiology, Massachusetts General Hospital, Boston, MA, USA; Institute of Medical Physics and Radiation Protection, THM, Life Science Engineering, Giessen, Germany
| | - Leonardo M Angelone
- Division of Biomedical Physics, Office of Science and Engineering Laboratories, Center for Devices and Radiological Health, US Food and Drug Administration, Silver Spring, MD, USA
| | - Giorgio Bonmassar
- Athinoula A. Martinos Center for Biomedical Imaging, Department of Radiology, Massachusetts General Hospital, Boston, MA, USA; Harvard Medical School, Boston, MA, USA
| | - Michael D Fox
- Berenson-Allen Center for Noninvasive Brain Stimulation, Beth Israel Deaconess Medical Center and Harvard Medical School, Boston, MA, USA
| | - Todd Herrington
- Partners Neurology, Massachusetts General Hospital, Brigham and Women's Hospital, Harvard Medical School, Boston, MA, USA
| | - Elfar Adalsteinsson
- Athinoula A. Martinos Center for Biomedical Imaging, Department of Radiology, Massachusetts General Hospital, Boston, MA, USA; Electrical Engineering and Computer Science, Massachusetts Institute of Technology, 77 Massachusetts Avenue, Cambridge, MA, USA
| | - Cristen LaPierre
- Athinoula A. Martinos Center for Biomedical Imaging, Department of Radiology, Massachusetts General Hospital, Boston, MA, USA
| | - Azma Mareyam
- Athinoula A. Martinos Center for Biomedical Imaging, Department of Radiology, Massachusetts General Hospital, Boston, MA, USA
| | - Lawrence L Wald
- Athinoula A. Martinos Center for Biomedical Imaging, Department of Radiology, Massachusetts General Hospital, Boston, MA, USA; Harvard Medical School, Boston, MA, USA
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Golestanirad L, Angelone LM, Iacono MI, Katnani H, Wald LL, Bonmassar G. Local SAR near deep brain stimulation (DBS) electrodes at 64 and 127 MHz: A simulation study of the effect of extracranial loops. Magn Reson Med 2016; 78:1558-1565. [PMID: 27797157 DOI: 10.1002/mrm.26535] [Citation(s) in RCA: 61] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2016] [Revised: 09/12/2016] [Accepted: 10/10/2016] [Indexed: 02/06/2023]
Abstract
PURPOSE MRI may cause brain tissue around deep brain stimulation (DBS) electrodes to become excessively hot, causing lesions. The presence of extracranial loops in the DBS lead trajectory has been shown to affect the specific absorption rate (SAR) of the radiofrequency energy at the electrode tip, but experimental studies have reported controversial results. The goal of this study was to perform a systematic numerical study to provide a better understanding of the effects of extracranial loops in DBS leads on the local SAR during MRI at 64 and 127 MHz. METHODS A total of 160 numerical simulations were performed on patient-derived data, in which relevant factors including lead length and trajectory, loop location and topology, and frequency of MRI radiofrequency (RF) transmitter were assessed. RESULTS Overall, the presence of extracranial loops reduced the local SAR in the tissue around the DBS tip compared with straight trajectories with the same length. SAR reduction was significantly larger at 127 MHz compared with 64 MHz. SAR reduction was significantly more sensitive to variable loop parameters (eg, topology and location) at 127 MHz compared with 64 MHz. CONCLUSION Lead management strategies could exist that significantly reduce the risks of 3 Tesla (T) MRI for DBS patients. Magn Reson Med 78:1558-1565, 2017. © 2016 International Society for Magnetic Resonance in Medicine.
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Affiliation(s)
- Laleh Golestanirad
- Athinoula A. Martinos Center for Biomedical Imaging, Department of Radiology, Massachusetts General Hospital, Harvard Medical School, Charlestown, Massachusetts, USA.,Harvard Medical School, Boston, Massachusetts, USA
| | - Leonardo M Angelone
- Division of Biomedical Physics, Office of Science and Engineering Laboratories, Center for Devices and Radiological Health, U.S. Food and Drug Administration, Silver Spring, Maryland, USA
| | - Maria Ida Iacono
- Division of Biomedical Physics, Office of Science and Engineering Laboratories, Center for Devices and Radiological Health, U.S. Food and Drug Administration, Silver Spring, Maryland, USA
| | - Husam Katnani
- Harvard Medical School, Boston, Massachusetts, USA.,Department of Neurosurgery, Massachusetts General Hospital, Harvard Medical School, Boston, Massachusetts, USA
| | - Lawrence L Wald
- Athinoula A. Martinos Center for Biomedical Imaging, Department of Radiology, Massachusetts General Hospital, Harvard Medical School, Charlestown, Massachusetts, USA.,Harvard Medical School, Boston, Massachusetts, USA
| | - Giorgio Bonmassar
- Athinoula A. Martinos Center for Biomedical Imaging, Department of Radiology, Massachusetts General Hospital, Harvard Medical School, Charlestown, Massachusetts, USA.,Harvard Medical School, Boston, Massachusetts, USA
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50
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Saleh C, Dooms G, Berthold C, Hertel F. Post-operative imaging in deep brain stimulation: A controversial issue. Neuroradiol J 2016; 29:244-9. [PMID: 27029393 PMCID: PMC4978322 DOI: 10.1177/1971400916639960] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
Abstract
In deep brain stimulation (DBS), post-operative imaging has been used on the one hand to assess complications, such as haemorrhage; and on the other hand, to detect misplaced contacts. The post-operative determination of the accurate location of the final electrode plays a critical role in evaluating the precise area of effective stimulation and for predicting the potential clinical outcome; however, safety remains a priority in postoperative DBS imaging. A plethora of diverse post-operative imaging methods have been applied at different centres. There is neither a consensus on the most efficient post-operative imaging methodology, nor is there any standardisation for the automatic or manual analysis of the images within the different imaging modalities. In this article, we give an overview of currently applied post-operative imaging modalities and discuss the current challenges in post-operative imaging in DBS.
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Affiliation(s)
- Christian Saleh
- Department of Neurology, Centre Hospitalier de Luxembourg, Luxembourg
| | - Georges Dooms
- Department of Neuroradiology, Centre Hospitalier de Luxembourg, Luxembourg
| | | | - Frank Hertel
- Department of Neurosurgery, Centre Hospitalier de Luxembourg, Luxembourg
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