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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 2024:10.1007/s10072-024-07513-9. [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] [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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2
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Bardwell Speltz LJ, Shu Y, Watson RE, Trzasko JD, In MH, Gray EM, Halverson MA, Tarasek MR, Hua Y, Huston J, Cogswell PM, Foo TKF, Bernstein MA. Evaluation of a compact 3 T MRI scanner for patients with implanted devices. Magn Reson Imaging 2023; 103:109-118. [PMID: 37468020 PMCID: PMC10528046 DOI: 10.1016/j.mri.2023.07.009] [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: 05/15/2023] [Revised: 07/14/2023] [Accepted: 07/14/2023] [Indexed: 07/21/2023]
Abstract
Access to high-quality MR exams is severely limited for patients with some implanted devices due to labeled MR safety conditions, but small-bore systems can overcome this limitation. For example, a compact 3 T MR scanner (C3T) with high-performance gradients can acquire exams of the head, extremities, and infants. Because of its reduced bore size and the patient being advanced only partially into the bore, the associated electromagnetic (EM) fields drop off rapidly caudal to the head, compared to whole-body systems. Therefore, some patients with MR conditional implanted devices can safely receive 3 T brain exams on the C3T using its strong gradients and a multiple-channel receive coil, while a corresponding exam on whole-body MR is precluded. The purpose of this study is to evaluate the performance of a small-bore scanner for subjects with MR conditional spinal or sacral nerve stimulators, or abandoned cardiac implantable electronic device (CIED) leads. The spatial dependence of specific absorption rate (SAR) on the C3T was compared to whole-body scanners. A device assessment tool was developed and applied to evaluate MR safety individually on the C3T for 12 subjects with implanted devices or abandoned CIED leads. Once MR safety was established, the subjects received a C3T brain exam along with their clinical, 1.5 T exam. The resulting images were graded by three board-certified neuroradiologists. The C3T exams were well-tolerated with no adverse events, and significantly outperformed the whole-body 1.5 T exams in terms of overall image quality.
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Affiliation(s)
- Lydia J Bardwell Speltz
- Department of Radiology, Mayo Clinic, Rochester, MN, United States; Mayo Clinic Graduate School of Biomedical Sciences, Mayo Clinic, Rochester, MN, United States
| | - Yunhong Shu
- Department of Radiology, Mayo Clinic, Rochester, MN, United States
| | - Robert E Watson
- Department of Radiology, Mayo Clinic, Rochester, MN, United States
| | - Joshua D Trzasko
- Department of Radiology, Mayo Clinic, Rochester, MN, United States
| | - Myung-Ho In
- Department of Radiology, Mayo Clinic, Rochester, MN, United States
| | - Erin M Gray
- Department of Radiology, Mayo Clinic, Rochester, MN, United States
| | | | | | - Yihe Hua
- GE Research, Niskayuna, NY, United States
| | - John Huston
- Department of Radiology, Mayo Clinic, Rochester, MN, United States
| | | | | | - Matt A Bernstein
- Department of Radiology, Mayo Clinic, Rochester, MN, United States.
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Perioperative Management of Nonorthopaedic Devices in the Pediatric Neuromuscular Patient Population. J Am Acad Orthop Surg 2023; 31:e403-e411. [PMID: 36853883 DOI: 10.5435/jaaos-d-22-00634] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/12/2022] [Accepted: 01/25/2023] [Indexed: 03/01/2023] Open
Abstract
Pediatric patients with neuromuscular conditions often have nonorthopaedic implants that can pose a challenge for MRI acquisition and surgical planning. Treating physicians often find themselves in the position of navigating between seemingly overly risk-averse manufacturer's guidelines and an individual patient's benefits of an MRI or surgery. Most nonorthopaedic implants are compatible with MRI under specific conditions, though often require reprogramming or interrogation before and/or after the scan. For surgical procedures, the use of electrosurgical instrumentation poses a risk of electromagnetic interference and implants are thus often programmed or turned off for the procedures. Special considerations are needed for these patients to prevent device damage or malfunction, which can pose additional risk to the patient. Additional planning before surgery is necessary to ensure appropriate equipment, and staff are available to ensure patient safety.
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Katzell L, Beydler EM, Holbert R, Rodriguez-Roman L, Carr BR. Electroconvulsive therapy use for refractory status epilepticus in an implantable vagus nerve stimulation patient: A case report. Front Psychiatry 2023; 14:1126956. [PMID: 36816412 PMCID: PMC9935692 DOI: 10.3389/fpsyt.2023.1126956] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/18/2022] [Accepted: 01/19/2023] [Indexed: 02/05/2023] Open
Abstract
INTRODUCTION Status epilepticus (SE) has a mortality rate of 20 to 50%, with acute symptomatic SE having a higher risk compared to chronic SE. Electroconvulsive therapy (ECT) has been utilized for the treatment of refractory SE with a success rate estimate of 57.9%. There are no known reported cases of concomitant use of vagus nerve stimulation (VNS) and ECT for the treatment of super refractory SE (SRSE) available in the literature. CASE DESCRIPTION We present a 44-year-old female with a history of developmental delay, epilepsy, an implantable VNS for 6 years, and traumatic brain injury with subsequent hygroma who presented with progressive aphasia, declining mental status, and daily generalized seizures lasting up to 20 min. Seizures had increased from her baseline of one seizure per day controlled with topiramate 200 mg three times daily and lamotrigine 400 mg twice daily. She was diagnosed with SRSE after being intubated and placed on eight anti-epileptic drugs (AEDs) that failed to abort SE. ECT was attempted to terminate SE. Due to a prior right craniotomy with subsequent right hygroma, eight treatments of ECT were performed over three sessions using a right anterior, left temporal (RALT) and subsequently a bitemporal electrode placement. The VNS remained active throughout treatment. Various ECT dosing parameters were attempted, varying pulse width and frequency. Although ECT induced mild transient encephalographic (EEG) changes following ECT stimulations, it was unable to terminate SE. DISCUSSION This case describes various treatment strategies, constraints, and device limitations when using ECT for the treatment of SE. With wide variability in efficacy rates of ECT in the treatment of SE in the literature, successful and unsuccessful cases offer information on optimizing ECT total charge dose and parameters that yielded success. This case demonstrates an instance of ECT inefficacy in the treatment of SRSE. Here, we discuss the rationale behind the various ECT settings that were selected, and constraints arising from the antiepileptic burden, VNS, and intrinsic limitations of the ECT device itself.
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Affiliation(s)
- Lauren Katzell
- College of Medicine, University of Florida, Gainesville, FL, United States
| | - Emily M Beydler
- College of Medicine, University of Florida, Gainesville, FL, United States
| | - Richard Holbert
- Department of Psychiatry, University of Florida, Gainesville, FL, United States
| | | | - Brent R Carr
- Department of Psychiatry, University of Florida, Gainesville, FL, United States
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5
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Jeong H, Cho A, Ay I, Bonmassar G. Short-pulsed micro-magnetic stimulation of the vagus nerve. Front Physiol 2022; 13:938101. [PMID: 36277182 PMCID: PMC9585240 DOI: 10.3389/fphys.2022.938101] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2022] [Accepted: 09/01/2022] [Indexed: 11/30/2022] Open
Abstract
Vagus nerve stimulation (VNS) is commonly used to treat drug-resistant epilepsy and depression. The therapeutic effect of VNS depends on stimulating the afferent vagal fibers. However, the vagus is a mixed nerve containing afferent and efferent fibers, and the stimulation of cardiac efferent fibers during VNS may produce a rare but severe risk of bradyarrhythmia. This side effect is challenging to mitigate since VNS, via electrical stimulation technology used in clinical practice, requires unique electrode design and pulse optimization for selective stimulation of only the afferent fibers. Here we describe a method of VNS using micro-magnetic stimulation (µMS), which may be an alternative technique to induce a focal stimulation, enabling a selective fiber stimulation. Micro-coils were implanted into the cervical vagus nerve in adult male Wistar rats. For comparison, the physiological responses were recorded continuously before, during, and after stimulation with arterial blood pressure (ABP), respiration rate (RR), and heart rate (HR). The electrical VNS caused a decrease in ABP, RR, and HR, whereas µM-VNS only caused a transient reduction in RR. The absence of an HR modulation indicated that µM-VNS might provide an alternative technology to VNS with fewer heart-related side effects, such as bradyarrhythmia. Numerical electromagnetic simulations helped estimate the optimal coil orientation with respect to the nerve to provide information on the electric field’s spatial distribution and strength. Furthermore, a transmission emission microscope provided very high-resolution images of the cervical vagus nerve in rats, which identified two different populations of nerve fibers categorized as large and small myelinated fibers.
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Affiliation(s)
- Hongbae Jeong
- Athinoula A. Martinos Center for Biomedical Imaging, Massachusetts General Hospital, Harvard Medical School, Charlestown, MA, United States
| | - Annabel Cho
- Athinoula A. Martinos Center for Biomedical Imaging, Massachusetts General Hospital, Harvard Medical School, Charlestown, MA, United States
- Department of Bioengineering, Harvard University, Cambridge, MA, United States
| | - Ilknur Ay
- Athinoula A. Martinos Center for Biomedical Imaging, Massachusetts General Hospital, Harvard Medical School, Charlestown, MA, United States
| | - Giorgio Bonmassar
- Athinoula A. Martinos Center for Biomedical Imaging, Massachusetts General Hospital, Harvard Medical School, Charlestown, MA, United States
- *Correspondence: Giorgio Bonmassar,
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Yang E, Suzuki M, Nazarian S, Halperin H. Magnetic Resonance Imaging Safety in Patients with Cardiac Implantable Electronic Devices. Trends Cardiovasc Med 2021; 32:440-447. [PMID: 34384880 DOI: 10.1016/j.tcm.2021.08.001] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/29/2019] [Revised: 08/02/2021] [Accepted: 08/03/2021] [Indexed: 10/20/2022]
Abstract
High strength magnetic and electric fields used in magnetic resonance imaging (MRI) render images with unmatched soft tissue contrast. These imaging attributes have made MRI an increasingly preferred diagnostic tool in many medical conditions. Initially there was substantial concern regarding the safety of performing these imaging studies in patients with cardiac implantable electronic devices (CIEDs), which have the potential to be affected by the intense electric and magnetic fields of the MRI. More recently, there has been increasing evidence that MRI can be performed safely in patients with devices that have not been specifically labelled by regulatory agencies for use in an MRI environment (MRI nonconditional devices), which has allowed the Centers for Medicare and Medicaid Services (CMS) to start providing reimbursement for MRIs of patients with MRI nonconditional devices. For CMS to reimburse scans, a rigorous protocol must be followed, which recognizes that there are still potential adverse effects that can be mitigated by appropriate procedures. In this review we will survey the initial experiences and efforts to understand the magnitude of risk for device malfunction and harm, as well as current efforts to minimize the potential risks of MRI effects on devices and leads (heating, device movement, lead dislodgement, and device malfunction, the latter including inhibition of pacing and generation of arrhythmias).
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Affiliation(s)
- Eunice Yang
- Johns Hopkins Hospital, Division of Cardiology, Baltimore, MD
| | - Masahito Suzuki
- Johns Hopkins Hospital, Division of Cardiology, Baltimore, MD
| | - Saman Nazarian
- University of Pennsylvania, Division of Cardiology, Philadelphia, PA
| | - Henry Halperin
- Johns Hopkins Hospital, Division of Cardiology, Baltimore, MD; Johns Hopkins University, Departments of Radiology and Biomedical Engineering.
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A systematic review of magnetic resonance imaging in patients with an implanted vagus nerve stimulation system. Neuroradiology 2021; 63:1407-1417. [PMID: 33846830 PMCID: PMC8376717 DOI: 10.1007/s00234-021-02705-y] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2021] [Accepted: 03/29/2021] [Indexed: 12/20/2022]
Abstract
Purpose Vagus nerve stimulation (VNS) is an effective adjunctive treatment for drug-resistant epilepsy (DRE) and difficult-to-treat depression (DTD). More than 125.000 patients have been implanted with VNS Therapy® System (LivaNova PLC) since initial approval. Patients with DRE often require magnetic resonance imaging (MRI) of the brain during the course of their disease. VNS Therapy System devices are labeled to allow MRI under certain conditions; however, there are no published comprehensive articles about the real-world experience using MRI in patients with implanted VNS devices. Methods A systematic review in accordance with PRISMA statement was performed using PubMed database. Full-length articles reporting MRI (1.5 T or 3 T scanner) of patients with implanted VNS for DRE or DTD and published since 2000 were included. The primary endpoint was a positive outcome that was defined as a technically uneventful MRI scan performed in accordance with the VNS Therapy System manufacturer guidelines and completed according to the researchers’ planned scanning protocol without harm to the patient. Results Twenty-six articles were eligible with 25 articles referring to the VNS Therapy System, and 216 patients were included in the analysis. No serious adverse events or serious device-related adverse events were reported. MRI scan was prematurely terminated in one patient due to a panic attack. Conclusion This systematic review indicates that cranial MRI of patients with an implanted VNS Therapy System can be completed satisfactorily and is tolerable and safe using 1.5 T and 3 T MRI scanners when performed in adherence to the VNS manufacturer’s guidelines. Supplementary Information The online version contains supplementary material available at 10.1007/s00234-021-02705-y.
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8
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Jeong H, Ntolkeras G, Alhilani M, Atefi SR, Zöllei L, Fujimoto K, Pourvaziri A, Lev MH, Grant PE, Bonmassar G. Development, validation, and pilot MRI safety study of a high-resolution, open source, whole body pediatric numerical simulation model. PLoS One 2021; 16:e0241682. [PMID: 33439896 PMCID: PMC7806143 DOI: 10.1371/journal.pone.0241682] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2020] [Accepted: 10/19/2020] [Indexed: 11/30/2022] Open
Abstract
Numerical body models of children are used for designing medical devices, including but not limited to optical imaging, ultrasound, CT, EEG/MEG, and MRI. These models are used in many clinical and neuroscience research applications, such as radiation safety dosimetric studies and source localization. Although several such adult models have been reported, there are few reports of full-body pediatric models, and those described have several limitations. Some, for example, are either morphed from older children or do not have detailed segmentations. Here, we introduce a 29-month-old male whole-body native numerical model, "MARTIN", that includes 28 head and 86 body tissue compartments, segmented directly from the high spatial resolution MRI and CT images. An advanced auto-segmentation tool was used for the deep-brain structures, whereas 3D Slicer was used to segment the non-brain structures and to refine the segmentation for all of the tissue compartments. Our MARTIN model was developed and validated using three separate approaches, through an iterative process, as follows. First, the calculated volumes, weights, and dimensions of selected structures were adjusted and confirmed to be within 6% of the literature values for the 2-3-year-old age-range. Second, all structural segmentations were adjusted and confirmed by two experienced, sub-specialty certified neuro-radiologists, also through an interactive process. Third, an additional validation was performed with a Bloch simulator to create synthetic MR image from our MARTIN model and compare the image contrast of the resulting synthetic image with that of the original MRI data; this resulted in a "structural resemblance" index of 0.97. Finally, we used our model to perform pilot MRI safety simulations of an Active Implantable Medical Device (AIMD) using a commercially available software platform (Sim4Life), incorporating the latest International Standards Organization guidelines. This model will be made available on the Athinoula A. Martinos Center for Biomedical Imaging website.
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Affiliation(s)
- Hongbae Jeong
- Athinoula A. Martinos Center for Biomedical Imaging, Massachusetts General Hospital, Harvard Medical School, Boston, MA, United States of America
- Department of Radiology, Massachusetts General Hospital, Harvard Medical School, Boston, MA, United States of America
| | - Georgios Ntolkeras
- Athinoula A. Martinos Center for Biomedical Imaging, Massachusetts General Hospital, Harvard Medical School, Boston, MA, United States of America
- Fetal-Neonatal Neuroimaging and Developmental Science Center, Boston Children’s Hospital, Harvard Medical School, Boston, MA, United States of America
| | - Michel Alhilani
- Fetal-Neonatal Neuroimaging and Developmental Science Center, Boston Children’s Hospital, Harvard Medical School, Boston, MA, United States of America
- Department of Medicine, Charing Cross Hospital, Imperial College Healthcare NHS Trust, London, United Kingdom
| | - Seyed Reza Atefi
- Athinoula A. Martinos Center for Biomedical Imaging, Massachusetts General Hospital, Harvard Medical School, Boston, MA, United States of America
- Department of Radiology, Massachusetts General Hospital, Harvard Medical School, Boston, MA, United States of America
| | - Lilla Zöllei
- Athinoula A. Martinos Center for Biomedical Imaging, Massachusetts General Hospital, Harvard Medical School, Boston, MA, United States of America
- Department of Radiology, Massachusetts General Hospital, Harvard Medical School, Boston, MA, United States of America
| | - Kyoko Fujimoto
- Center for Devices and Radiological Health, U. S. Food and Drug Administration, Silver Spring, MD, United States of America
| | - Ali Pourvaziri
- Department of Radiology, Massachusetts General Hospital, Harvard Medical School, Boston, MA, United States of America
| | - Michael H. Lev
- Department of Radiology, Massachusetts General Hospital, Harvard Medical School, Boston, MA, United States of America
| | - P. Ellen Grant
- Fetal-Neonatal Neuroimaging and Developmental Science Center, Boston Children’s Hospital, Harvard Medical School, Boston, MA, United States of America
| | - Giorgio Bonmassar
- Athinoula A. Martinos Center for Biomedical Imaging, Massachusetts General Hospital, Harvard Medical School, Boston, MA, United States of America
- Department of Radiology, Massachusetts General Hospital, Harvard Medical School, Boston, MA, United States of America
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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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Yang R, Zheng J, Wang Y, Guo R, Kainz W, Chen J. Impact of Electrode Structure on RF-Induced Heating for an AIMD Implanted Lead in a 1.5-Tesla MRI System. ACTA ACUST UNITED AC 2019. [DOI: 10.1109/jerm.2019.2913111] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
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11
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Jabehdar Maralani P, Schieda N, Hecht EM, Litt H, Hindman N, Heyn C, Davenport MS, Zaharchuk G, Hess CP, Weinreb J. MRI safety and devices: An update and expert consensus. J Magn Reson Imaging 2019; 51:657-674. [PMID: 31566852 DOI: 10.1002/jmri.26909] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2019] [Revised: 07/31/2019] [Accepted: 08/01/2019] [Indexed: 12/22/2022] Open
Abstract
The use of magnetic resonance imaging (MRI) is increasing globally, and MRI safety issues regarding medical devices, which are constantly being developed or upgraded, represent an ongoing challenge for MRI personnel. To assist the MRI community, a panel of 10 radiologists with expertise in MRI safety from nine high-volume academic centers formed, with the objective of providing clarity on some of the MRI safety issues for the 10 most frequently questioned devices. Ten device categories were identified. The panel reviewed the literature, including key MRI safety issues regarding screening and adverse event reports, in addition to the manufacturer's Instructions For Use. Using a Delphi-inspired method, 36 practical recommendations were generated with 100% consensus that can aid the clinical MRI community. Level of Evidence: 5 Technical Efficacy Stage: 5 J. Magn. Reson. Imaging 2020;51:657-674.
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Affiliation(s)
| | - Nicola Schieda
- Department of Radiology, University of Ottawa, Ottawa, Canada
| | - Elizabeth M Hecht
- Department of Radiology, Columbia University, New York, New York, USA
| | - Harold Litt
- Department of Radiology, University of Pennsylvania, Philadelphia, Pennsylvania, USA
| | - Nicole Hindman
- Department of Radiology, New York University, New York, New York, USA
| | - Chinthaka Heyn
- Department of Medical Imaging, University of Toronto, Toronto, Canada
| | | | - Greg Zaharchuk
- Department of Radiology, Stanford University, Stanford, California, USA
| | - Christopher P Hess
- Department of Radiology and Biomedical Imaging, University of California, San Francisco, California, USA
| | - Jeffrey Weinreb
- Department of Radiology and Biomedical Imaging, Yale University, New Haven, Connecticut, USA
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12
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13
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Favazza CP, Edmonson HA, Ma C, Shu Y, Felmlee JP, Watson RE, Gorny KR. Evaluation of feasibility of 1.5 Tesla prostate MRI using body coil RF transmit in a patient with an implanted vagus nerve stimulator. Med Phys 2017; 44:5749-5754. [PMID: 28880381 DOI: 10.1002/mp.12567] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2017] [Revised: 06/29/2017] [Accepted: 08/23/2017] [Indexed: 11/06/2022] Open
Abstract
PURPOSE To assess risks of RF-heating of a vagus nerve stimulator (VNS) during 1.5 T prostate MRI using body coil transmit and to compare these risks with those associated with MRI head exams using a transmit/receive head coil. METHODS Spatial distributions of radio-frequency (RF) B1 fields generated by transmit/receive (T/R) body and head coils were empirically assessed along the long axis of a 1.5 T MRI scanner bore. Measurements were obtained along the center axis of the scanner and laterally offset by 15 cm (body coil) and 7 cm (head coil). RF-field measurements were supplemented with direct measurements of RF-heating of 15 cm long copper wires affixed to and submerged in the "neck" region of the gelled saline-filled (sodium chloride and polyacrylic acid) "head-and-torso" phantom. Temperature elevations at the lead tips were measured using fiber-optic thermometers with the phantom positioned at systematically increased distances from the scanner isocenter. RESULTS B1 field measurements demonstrated greater than 10 dB reduction in RF power at distances beyond 28 cm and 24 cm from isocenter for body and head coil, respectively. Moreover, RF power from body coil transmit at distances greater than 32 cm from isocenter was found to be lower than from the RF power from head coil transmit measured at locations adjacent to the coil array at its opening. Correspondingly, maximum temperature elevations at the tips of the copper wires decreased with increasing distance from isocenter - from 7.4°C at 0 cm to no appreciable heating at locations beyond 40 cm. CONCLUSIONS For the particular scanner model evaluated in this study, positioning an implanted VNS farther than 32 cm from isocenter (configuration achievable for prostate exams) can reduce risks of RF-heating resulting from the body coil transmit to those associated with using a T/R head coil.
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Affiliation(s)
| | | | - Chi Ma
- Department of Radiology, Mayo Clinic, Rochester, MN, 55905, USA
| | - Yunhong Shu
- Department of Radiology, Mayo Clinic, Rochester, MN, 55905, USA
| | - Joel P Felmlee
- Department of Radiology, Mayo Clinic, Rochester, MN, 55905, USA
| | - Robert E Watson
- Department of Radiology, Mayo Clinic, Rochester, MN, 55905, USA
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14
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Panych LP, Madore B. The physics of MRI safety. J Magn Reson Imaging 2017; 47:28-43. [DOI: 10.1002/jmri.25761] [Citation(s) in RCA: 82] [Impact Index Per Article: 11.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2017] [Accepted: 04/24/2017] [Indexed: 01/25/2023] Open
Affiliation(s)
- Lawrence P. Panych
- Department of Radiology; Brigham and Women's Hospital; Boston Massachusetts USA
- Harvard Medical School; Boston Massachusetts USA
| | - Bruno Madore
- Department of Radiology; Brigham and Women's Hospital; Boston Massachusetts USA
- Harvard Medical School; Boston Massachusetts USA
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15
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Thornton JS. Technical challenges and safety of magnetic resonance imaging with in situ neuromodulation from spine to brain. Eur J Paediatr Neurol 2017; 21:232-241. [PMID: 27430172 DOI: 10.1016/j.ejpn.2016.06.001] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/03/2016] [Accepted: 06/13/2016] [Indexed: 10/21/2022]
Abstract
PURPOSE This review summarises the need for MRI with in situ neuromodulation, the key safety challenges and how they may be mitigated, and surveys the current status of MRI safety for the main categories of neuro-stimulation device, including deep brain stimulation, vagus nerve stimulation, sacral neuromodulation, spinal cord stimulation systems, and cochlear implants. REVIEW SUMMARY When neuro-stimulator systems are introduced into the MRI environment a number of hazards arise with potential for patient harm, in particular the risk of thermal injury due to MRI-induced heating. For many devices however, safe MRI conditions can be determined, and MRI safely performed, albeit with possible compromise in anatomical coverage, image quality or extended acquisition time. CONCLUSIONS The increasing availability of devices conditional for 3 T MRI, whole-body transmit imaging, and imaging in the on-stimulation condition, will be of significant benefit to the growing population of patients benefitting from neuromodulation therapy, and open up new opportunities for functional imaging research.
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Affiliation(s)
- John S Thornton
- Lysholm Department of Neuroradiology, National Hospital for Neurology and Neurosurgery, UCLH NHS Foundation Trust, Queen Square, London, UK; Neuroradiological Academic Unit, Department of Brain Repair and Rehabilitation, UCL Institute of Neurology, University College London, London, UK.
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16
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Nagae LM, Lall N, Dahmoush H, Nyberg E, Mirsky D, Drees C, Honce JM. Diagnostic, treatment, and surgical imaging in epilepsy. Clin Imaging 2016; 40:624-36. [DOI: 10.1016/j.clinimag.2016.02.012] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2015] [Revised: 02/03/2016] [Accepted: 02/11/2016] [Indexed: 10/22/2022]
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17
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18
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3T-MRI in patients with pharmacoresistant epilepsy and a vagus nerve stimulator: A pilot study. Epilepsy Res 2015; 110:62-70. [DOI: 10.1016/j.eplepsyres.2014.11.010] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2014] [Revised: 10/25/2014] [Accepted: 11/11/2014] [Indexed: 12/30/2022]
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19
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de Jonge JC, Melis GI, Gebbink TA, de Kort GAP, Leijten FSS. Safety of a dedicated brain MRI protocol in patients with a vagus nerve stimulator. Epilepsia 2014; 55:e112-5. [DOI: 10.1111/epi.12774] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 08/04/2014] [Indexed: 11/28/2022]
Affiliation(s)
- Jeroen C. de Jonge
- Department of Neurology and Neurosurgery; Brain Center Rudolf Magnus; University Medical Center Utrecht; Utrecht The Netherlands
| | - Gerrit I. Melis
- Department of Radiology; University Medical Center Utrecht; Utrecht The Netherlands
| | - Tineke A. Gebbink
- Department of Neurology and Neurosurgery; Brain Center Rudolf Magnus; University Medical Center Utrecht; Utrecht The Netherlands
| | - Gérard A. P. de Kort
- Department of Radiology; University Medical Center Utrecht; Utrecht The Netherlands
| | - Frans S. S. Leijten
- Department of Neurology and Neurosurgery; Brain Center Rudolf Magnus; University Medical Center Utrecht; Utrecht The Netherlands
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20
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Korb AS, Shellock FG, Cohen MS, Bystritsky A. Low-Intensity Focused Ultrasound Pulsation Device Used During Magnetic Resonance Imaging: Evaluation of Magnetic Resonance Imaging-Related Heating at 3 Tesla/128 MHz. Neuromodulation 2013; 17:236-41; discussion 241. [DOI: 10.1111/ner.12075] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2012] [Revised: 03/22/2013] [Accepted: 04/02/2013] [Indexed: 11/28/2022]
Affiliation(s)
- Alexander S. Korb
- Department of Psychiatry and Biobehavioral Sciences; University of California; Los Angeles CA USA
| | - Frank G. Shellock
- Department of Radiology; University of Southern California; Los Angeles CA USA
| | - Mark S. Cohen
- Department of Psychiatry and Biobehavioral Sciences; University of California; Los Angeles CA USA
- Departments of Neurology, Radiology, Psychology, Biomedical Physics, and Bioengineering; University of California; Los Angeles CA USA
| | - Alexander Bystritsky
- Department of Psychiatry and Biobehavioral Sciences; University of California; Los Angeles CA USA
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21
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Patel KS, Moussazadeh N, Doyle WK, Labar DR, Schwartz TH. Efficacy of vagus nerve stimulation in brain tumor-associated intractable epilepsy and the importance of tumor stability. J Neurosurg 2013; 119:520-5. [PMID: 23600931 DOI: 10.3171/2013.3.jns121890] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
OBJECT Vagus nerve stimulation (VNS) is a viable option for patients with medically intractable epilepsy. However, there are no studies examining its effect on individuals with brain tumor-associated intractable epilepsy. This study aims to evaluate the efficacy of VNS in patients with brain tumor-associated medically intractable epilepsy. METHODS Epilepsy surgery databases at 2 separate epilepsy centers were reviewed to identify patients in whom a VNS device was placed for tumor-related intractable epilepsy between January 1999 and December 2011. Preoperative and postoperative seizure frequency and type as well as antiepileptic drug (AED) regimens and degree of tumor progression were evaluated. Statistical analysis was performed using odds ratios and t-tests to examine efficacy. RESULTS Sixteen patients were included in the study. Eight patients (50%) had an improved outcome (Engel Class I, II, or III) with an average follow-up of 39.6 months. The mean reduction in seizure frequency was 41.7% (p = 0.002). There was no significant change in AED regimens. Seizure frequency decreased by 10.9% in patients with progressing tumors and by 65.6% in patients with stable tumors (p = 0.008). CONCLUSIONS Vagus nerve stimulation therapy in individuals with brain tumor-associated medically intractable epilepsy was shown to be comparably effective in regard to seizure reduction and response rates to the general population of VNS therapy patients. Outcomes were better in patients with stable as opposed to progressing tumors. The authors' findings support the recommendation of VNS therapy in patients with brain tumor-associated intractable epilepsy, especially in cases in which imminent tumor progression is not expected. Vagus nerve stimulation may not be indicated in more malignant tumors.
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Affiliation(s)
- Kunal S Patel
- Departments of Neurological Surgery, Weill Cornell Medical College, New York Presbyterian Hospital, New York, NY 10065, USA
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22
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Assessment of MRI issues for the Argus II Retinal Prosthesis. Magn Reson Imaging 2012; 30:382-9. [DOI: 10.1016/j.mri.2011.12.005] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2011] [Revised: 10/23/2011] [Accepted: 12/04/2011] [Indexed: 11/17/2022]
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23
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Cervical external immobilization devices: evaluation of magnetic resonance imaging issues at 3.0 Tesla. Spine (Phila Pa 1976) 2010; 35:411-5. [PMID: 20110847 DOI: 10.1097/brs.0b013e3181b0e9f8] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
STUDY DESIGN Laboratory investigation, ex vivo. OBJECTIVE Currently, no studies have addressed the magnetic resonance imaging (MRI) issues for cervical external immobilization devices at 3-Tesla. Under certain conditions significant heating may occur, resulting in patient burns. Furthermore, artifacts can be substantial and prevent the diagnostic use of MRI. Therefore, the objective of this investigation was to evaluate MRI issues for 4 different cervical external immobilization devices at 3-Tesla. SUMMARY OF BACKGROUND DATA Excessive heating and substantial artifacts are 2 potential complications associated with performing MRI at 3-Tesla in patients with cervical external immobilization devices. Using ex vivo testing techniques, MRI-related heating and artifacts were evaluated for 4 different cervical devices during MRI at 3-Tesla. METHODS Four cervical external immobilization devices (Generation 80, Resolve Ring and Superstructure, Resolve Ring and Jerome Vest/Jerome Superstructure, and the V1 Halo System; Ossur Americas, Aliso Viejo, CA) underwent MRI testing at 3-Tesla. All devices were made from nonmetallic or nonmagnetic materials. Heating was determined using a gelled-saline-filled skull phantom with fluoroptic thermometry probes attached to the skull pins. MRI was performed at 3-Tesla, using a high level of RF energy. Artifacts were assessed at 3-Tesla, using standard cervical imaging techniques. RESULTS The Generation 80 and V1 Halo devices exhibited substantial temperature rises (11.6 degrees C and 8.5 degrees C, respectively), with "sparking" evident for the Generation 80 during the MRI procedure. Artifacts were problematic for these devices, as well. By comparison, the 2 Resolve Ring-based cervical external immobilization devices showed little or no heating (< or = 0.6 degrees C) and the artifacts were acceptable for diagnostic MRI examinations. CONCLUSION The low degree of heating and minor artifacts associated with the Resolve-based cervical external immobilization devices indicated that these products are safe for patients undergoing MRI at 3-Tesla.
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Gorny KR, Bernstein MA, Watson RE. 3 tesla MRI of patients with a vagus nerve stimulator: Initial experience using a T/R head coil under controlled conditions. J Magn Reson Imaging 2010; 31:475-81. [DOI: 10.1002/jmri.22037] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
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Shellock FG. Excessive temperature increases in pacemaker leads at 3-T MR imaging with a transmit-receive head coil. Radiology 2009; 251:948-9; author reply 949-50. [PMID: 19474383 DOI: 10.1148/radiol.2513090034] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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Roebling R, Huch K, Kassubek J, Lerche H, Weber Y. Cervical spinal MRI in a patient with a vagus nerve stimulator (VNS). Epilepsy Res 2009; 84:273-5. [PMID: 19269790 DOI: 10.1016/j.eplepsyres.2009.02.008] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2008] [Revised: 01/26/2009] [Accepted: 02/01/2009] [Indexed: 10/21/2022]
Abstract
Cranial MRI has been shown to be a safe procedure in patients with a vagus nerve stimulator (VNS), but body MRI may cause overheating of the stimulator lead. Here we report a case of a patient with an implanted vagus nerve stimulator who required a cervical spinal MRI due to a rapidly progressive paraparesis. The spinal MRI was performed in a 1.5T scanner without complications showing a nearly complete compression of the spinal cord.
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27
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MRI Safety and Neuromodulation Systems. Neuromodulation 2009. [DOI: 10.1016/b978-0-12-374248-3.00021-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register]
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28
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Shellock FG, Crivelli R, Venugopalan R. Programmable Infusion Pump and Catheter: Evaluation Using 3-Tesla Magnetic Resonance Imaging. Neuromodulation 2008; 11:163-70. [DOI: 10.1111/j.1525-1403.2008.00162.x] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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Shellock FG, Valencerina S. Ventricular assist device implant (AB 5000) prototype cannula: in vitro assessment of MRI issues at 3-Tesla. J Cardiovasc Magn Reson 2008; 10:23. [PMID: 18495028 PMCID: PMC2440740 DOI: 10.1186/1532-429x-10-23] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2008] [Accepted: 05/21/2008] [Indexed: 11/11/2022] Open
Abstract
PURPOSE To evaluate MRI issues at 3-Tesla for a ventricular assist device (VAD). METHODS The AB5000 Ventricle with a prototype Nitinol wire-reinforced In-Flow Cannula and Out-Flow Cannula attached (Abiomed, Inc., Danvers, MA) was evaluated for magnetic field interactions, heating, and artifacts at 3-Tesla. MRI-related heating was assessed with the device in a gelled-saline-filled, head/torso phantom using a transmit/received RF body coil while performing MRI at a whole body averaged SAR of 3-W/kg for 15-min. Artifacts were assessed for the main metallic component of this VAD (atrial cannula) using T1-weighted, spin echo and gradient echo pulse sequences. RESULTS The AB5000 Ventricle with the prototype In-Flow Cannula and Out-Flow Cannula attached showed relatively minor magnetic field interactions that will not cause movement in situ. Heating was not excessive (highest temperature change, +0.8 degrees C). Artifacts may create issues for diagnostic imaging if the area of interest is in the same area or close to the implanted metallic component of this VAD (i.e., the venous cannula). CONCLUSION The results of this investigation demonstrated that it would be acceptable for a patient with this VAD (AB5000 Ventricle with a prototype Nitinol wire-reinforced In-Flow Cannula and Out-Flow Cannula attached) to undergo MRI at 3-Tesla or less. Notably, it is likely that the operation console for this device requires positioning a suitable distance (beyond the 100 Gauss line or in the MR control room) from the 3-Tesla MR system to ensure proper function of the VAD.
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Affiliation(s)
- Frank G Shellock
- Keck School of Medicine, University of Southern California and Institute for Magnetic Resonance Safety, Education, and Research, Los Angeles, CA, USA
| | - Samuel Valencerina
- University of Southern California, University Hospital, Los Angeles, CA, USA
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Shellock FG, Wilson SF, Mauge CP. Magnetically programmable shunt valve: MRI at 3-Tesla. Magn Reson Imaging 2007; 25:1116-21. [PMID: 17707175 DOI: 10.1016/j.mri.2006.12.004] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2006] [Revised: 12/06/2006] [Accepted: 12/07/2006] [Indexed: 10/23/2022]
Abstract
A magnetically programmable cerebrospinal fluid (CSF) shunt valve (Codman Hakim Programmable Valve, Codman, a Johnson & Johnson Company, Raynham, MA) was assessed for magnetic field interactions, heating, artifacts and functional changes at 3-Tesla. The programmable valve showed minor magnetic field interactions and heating (+0.4 degrees C). Artifacts were relatively large in relation to the size and shape of this implant and, as such, may create a problem if the area of interest is in proximity to this implant. While multiple exposures and various magnetic resonance imaging (MRI) conditions at 3-Tesla changed the settings of some valves (i.e., reprogramming was needed), the function of the programmable valve was not permanently affected. Therefore, this magnetically programmable CSF shunt valve is acceptable for a patient undergoing MRI at 3-Tesla or less when specific safety guidelines are followed, including resetting the valve, as needed.
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Affiliation(s)
- Frank G Shellock
- Keck School of Medicine, University of Southern California, Los Angeles, CA, USA.
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Kanal E, Barkovich AJ, Bell C, Borgstede JP, Bradley WG, Froelich JW, Gilk T, Gimbel JR, Gosbee J, Kuhni-Kaminski E, Lester JW, Nyenhuis J, Parag Y, Schaefer DJ, Sebek-Scoumis EA, Weinreb J, Zaremba LA, Wilcox P, Lucey L, Sass N. ACR Guidance Document for Safe MR Practices: 2007. AJR Am J Roentgenol 2007; 188:1447-74. [PMID: 17515363 DOI: 10.2214/ajr.06.1616] [Citation(s) in RCA: 442] [Impact Index Per Article: 26.0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Affiliation(s)
- Emanuel Kanal
- Department of Radiology, University of Pittsburgh Medical Center, Pittsburgh, PA, USA
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