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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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2
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Dudysheva N, Mauconduit F, Abdeddaim R, Gapais PF, Hosseinnezhadian S, Dubois M, Amadon A, Boulant N, Hertz-Pannier L, Vignaud A. The restricted SAR protocol: A method to assess MRI coil prototypes in an unconditionally safe manner. Magn Reson Med 2024; 91:1723-1734. [PMID: 38084471 DOI: 10.1002/mrm.29962] [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: 07/25/2023] [Revised: 10/24/2023] [Accepted: 11/17/2023] [Indexed: 02/03/2024]
Abstract
PURPOSE Testing an RF coil prototype on subjects involves laborious verifications to ensure its safety. In particular, it requires preliminary electromagnetic simulations and their validations on phantoms to accurately predict the specific absorption rate (SAR). For coil design validation with a simpler safety procedure, the restricted SAR (rS) mode is proposed, enabling representative first experiments in vivo. The goal of the developed approach is to accelerate the transition of a custom coil system from prototype to clinical use. METHODS The restricted specific absorption rate (SAR) (rS) mode imposes a radical limitation on the transmitted RF power based on a worst-case scenario of local RF power absorption. The limitations used are independent of the SAR spatial distribution, making this approach unconditionally safe. The developed rS protocol contains the sequences required for coil evaluation and satisfies the imposed rS conditions. It provides a quantitative characterization of the coil transmission and reception profiles and a qualitative evaluation of the anatomical images. Protocol validation was performed on commercial and pre-industrial prototype coils on a small cohort of healthy volunteers. RESULTS The proposed rS protocol enables coil evaluation within an acquisition time compatible with common clinical protocol duration. The total time of all evaluation steps does not exceed 17 min. At the same time, the global SAR remains 100 times less than the International Electrotechnical Commission safety limit for played sequences. CONCLUSION The rS protocol allows characterizing and comparing coil prototypes on volunteers without extensive electromagnetic calculations and phantom validations in an unconditionally safe way.
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Affiliation(s)
- Natalia Dudysheva
- Paris-Saclay University, CEA, CNRS, BAOBAB, NeuroSpin, Gif-sur-Yvette, France
- Multiwave Imaging, Marseille, France
| | - Franck Mauconduit
- Paris-Saclay University, CEA, CNRS, BAOBAB, NeuroSpin, Gif-sur-Yvette, France
| | - Redha Abdeddaim
- Aix Marseille Univ, CNRS, Centrale Marseille, Institut Fresnel, Institut Marseille Imaging, Marseille, France
| | | | | | | | - Alexis Amadon
- Paris-Saclay University, CEA, CNRS, BAOBAB, NeuroSpin, Gif-sur-Yvette, France
| | - Nicolas Boulant
- Paris-Saclay University, CEA, CNRS, BAOBAB, NeuroSpin, Gif-sur-Yvette, France
| | - Lucie Hertz-Pannier
- Paris-Saclay University, CEA, CNRS, BAOBAB, NeuroSpin, Gif-sur-Yvette, France
| | - Alexandre Vignaud
- Paris-Saclay University, CEA, CNRS, BAOBAB, NeuroSpin, Gif-sur-Yvette, France
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3
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Yazdani M, Reagan J, Kocher M, Antonucci M, Taylor J, Edwards J, Vandergrift WA, Spampinato MV. Safety of MRI in the localization of implanted intracranial electrodes for refractory epilepsy. J Neuroimaging 2021; 31:551-559. [PMID: 33783916 DOI: 10.1111/jon.12848] [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: 12/07/2020] [Revised: 01/27/2021] [Accepted: 02/17/2021] [Indexed: 11/26/2022] Open
Abstract
BACKGROUND AND PURPOSE This is an observational study to evaluate the safety of magnetic resonance imaging (MRI) to localize subdural grids and depth electrodes in patients with refractory epilepsy using a 1.5 Tesla MR scanner. METHODS We implemented an optimized MRI protocol providing adequate image quality for the assessment of subdural grids and depth electrodes, while minimizing the specific absorption rate (SAR). We reviewed all MRI studies performed in patients with subdural grids and depth electrodes between January 2010 and October 2018. Image quality was graded as acceptable or nonacceptable for the assessment of intracranial device positioning. We reviewed the medical record and any imaging obtained after intracranial implant removal for adverse event or complication occurring during and after the procedure. RESULTS Ninety-nine patients with refractory epilepsy underwent MRI scans using a magnetization-prepared rapid acquisition of gradient echo sequence and a transmit-receive head coil with depth electrodes and subdural grids in place. Two patients underwent two separate depth electrode implantations for a total of 101 procedures and MRI scans. No clinical adverse events were reported during or immediately after imaging. Image quality was graded as acceptable for 97 MRI scans. Review of follow-up CT and MRI studies after implant removal, available for 70 patients, did not demonstrate unexpected complications in 69 patients. CONCLUSION In our experience, a low SAR MRI protocol can be used to safely localize intracranial subdural grids and depth electrode in patients with refractory epilepsy.
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Affiliation(s)
- Milad Yazdani
- Department of Radiology and Radiological Science, Medical University of South Carolina, Charleston, SC
| | - Justin Reagan
- Department of Radiology and Radiological Science, Medical University of South Carolina, Charleston, SC
| | - Madison Kocher
- Department of Radiology and Radiological Science, Medical University of South Carolina, Charleston, SC
| | - Michael Antonucci
- Department of Radiology and Radiological Science, Medical University of South Carolina, Charleston, SC
| | - James Taylor
- Department of Radiology and Radiological Science, Medical University of South Carolina, Charleston, SC
| | - Jonathan Edwards
- Department of Neurosciences, Medical University of South Carolina, Charleston, SC
| | | | - Maria Vittoria Spampinato
- Department of Radiology and Radiological Science, Medical University of South Carolina, Charleston, SC
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4
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Ronde EM, Silvasti-Lundell M, Pekkola J, Tallgren M, Kivisaari R. Preoperative Magnetic Resonance Image Quality in Motion Disorder Patients Scheduled for Deep Brain Stimulation Surgery. Stereotact Funct Neurosurg 2020; 98:363-370. [PMID: 32957096 DOI: 10.1159/000506998] [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: 10/15/2019] [Accepted: 03/02/2020] [Indexed: 11/19/2022]
Abstract
BACKGROUND To obtain magnetic resonance (MR) images of good quality for accurate target localization in deep brain stimulation (DBS) surgery, sedation or anesthesia may be used, although their usefulness has not been proven. OBJECTIVE To assess whether sedation or general anesthesia (GA) improve the quality of MR imaging (MRI). METHODS The records of DBS procedures for Parkinson's disease (PD), dystonia, and essential tremor in our tertiary neurosurgical unit between January 2011 and June 2016 were reviewed. Adult patients with preoperative MR images were included. Patient records concerning MRI, surgery, adverse events, and clinical outcome were retrospectively scrutinized and analyzed. MR image quality was assessed by two independent radiologists. RESULTS A total of 215 preoperative MR images for 177 DBS procedures were analyzed. The MRI sequences performed under GA were superior to those performed without anesthesia or under sedation (p < 0.01). Virtually all images captured under GA were of good quality, while the proportions among those captured with sedation or without anesthesia were <65%. Good image quality was not associated with better clinical outcome (>50% improvement in the Unified Parkinson's Disease Rating Scale III score) among patients with PD. CONCLUSION GA was associated with better MRI sequences than intravenous sedation or no anesthesia.
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Affiliation(s)
- Elsa M Ronde
- Department of Anesthesia, Intensive Care and Pain Medicine, University of Helsinki and Helsinki University Hospital, Helsinki, Finland.,Academic Medical Center, University of Amsterdam, Amsterdam, The Netherlands
| | - Marja Silvasti-Lundell
- Department of Anesthesia, Intensive Care and Pain Medicine, University of Helsinki and Helsinki University Hospital, Helsinki, Finland
| | - Johanna Pekkola
- Department of Radiology, University of Helsinki and Helsinki University Hospital, Helsinki, Finland
| | - Minna Tallgren
- Department of Anesthesia, Intensive Care and Pain Medicine, University of Helsinki and Helsinki University Hospital, Helsinki, Finland
| | - Riku Kivisaari
- Department of Neurosurgery, University of Helsinki and Helsinki University Hospital, Helsinki, Finland,
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Bhusal B, Nguyen BT, Sanpitak PP, Vu J, Elahi B, Rosenow J, Nolt MJ, Lopez‐Rosado R, Pilitsis J, DiMarzio M, Golestanirad L. Effect of Device Configuration and Patient's Body Composition on the
RF
Heating and Nonsusceptibility Artifact of Deep Brain Stimulation Implants During
MRI
at 1.5T and 3T. J Magn Reson Imaging 2020; 53:599-610. [DOI: 10.1002/jmri.27346] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2020] [Revised: 08/12/2020] [Accepted: 08/13/2020] [Indexed: 12/13/2022] Open
Affiliation(s)
- Bhumi Bhusal
- Department of Radiology Northwestern University Chicago Illinois USA
| | - Bach T. Nguyen
- Department of Radiology Northwestern University Chicago Illinois USA
| | - Pia P. Sanpitak
- Department of Biomedical Engineering Northwestern University Chicago Illinois USA
| | - Jasmine Vu
- Department of Radiology Northwestern University Chicago Illinois USA
- Department of Biomedical Engineering Northwestern University Chicago Illinois USA
| | - Behzad Elahi
- Department of Physical Therapy and Human Movement Sciences Northwestern University Chicago Illinois USA
| | - Joshua Rosenow
- Department of Neurosurgery Northwestern University Chicago Illinois USA
| | - Mark J. Nolt
- Department of Neurosurgery Northwestern University Chicago Illinois USA
| | - Roberto Lopez‐Rosado
- Department of Physical Therapy and Human Movement Sciences Northwestern University Chicago Illinois USA
| | - Julie Pilitsis
- Department of Neurosciences and Experimental Therapeutics Albany Medical College Albany New York USA
| | - Marisa DiMarzio
- Department of Neurosciences and Experimental Therapeutics Albany Medical College Albany New York USA
| | - Laleh Golestanirad
- Department of Radiology Northwestern University Chicago Illinois USA
- Department of Biomedical Engineering Northwestern University Chicago Illinois USA
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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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7
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Lunden L, Wolff S, Peters S, Drews C, Gierloff C, Jensen-Kondering U, Langguth P, Madjidyar J, Piesch TC, Jansen O. MRI in patients with implanted active devices: how to combine safety and image quality using a limited transmission field? Eur Radiol 2020; 30:2571-2582. [PMID: 31974690 DOI: 10.1007/s00330-019-06599-6] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2019] [Revised: 10/09/2019] [Accepted: 11/20/2019] [Indexed: 11/27/2022]
Abstract
OBJECTIVES Radio frequency (RF) pulses in magnetic resonance imaging (MRI) can interact with implanted devices and cause tissue damage. However, there are new devices that can safely perform measurements with liberal MRI conditions such as an RF transmission field B1+rms ≤ 2.0 μT. We investigated whether MRI in this case is limited for these technical reasons. METHODS We selected typical MRI protocols of six body regions (brain, cervical spine, lumbar spine, knee, liver, heart) using two typical 1.5T MRI scanners. Overall, we adapted 62 sequences to B1+rms conditions and evaluated their diagnostic quality. For this, we measured signal-to-noise-ratio (SNR), contrast-to-noise-ratio (CNR), and geometric deviation (GD) as quality parameters, using phantom studies. For questionnaire studies, we selected pairs of original and adapted sequences in healthy volunteers. Blinded radiologists rated the images as single sequence rating and in direct comparison. RESULTS Roughly one-third of the checked sequences were below the B1+rms limit. Here, 56 of the 62 adapted sequences showed at least the same image quality in single ratings. A reduction in SNR and/or CNR was found with 31 sequences and only one sequence with considerably increased GD. Especially, sequences with original high B1+rms values, PD sequences, and sequences of the Siemens knee and heart protocol were difficult to adapt, whereas most TSE and IR sequences had no clinical limitations. CONCLUSION By limiting the transmission field to B1+rms ≤ 2.0 μT, clinically relevant MR sequences can be adapted with nearly no reduction in image quality. Despite limiting the transmission field, high-quality MR imaging is possible. We could derive strategies for adaptation. KEY POINTS • Despite limiting the transmission field, high-quality MRI is possible. • We could derive strategies for adapting the sequences to B1+rms≤ 2.0 μT. • This enables high-quality MRI of different body regions for patients with AD.
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Affiliation(s)
- Laura Lunden
- Department of Radiology and Neuroradiology, University Hospital Schleswig-Holstein Campus Kiel, Arnold-Heller-Straße 3, Haus 41, 24105, Kiel, Germany.
| | - Stephan Wolff
- Department of Radiology and Neuroradiology, University Hospital Schleswig-Holstein Campus Kiel, Arnold-Heller-Straße 3, Haus 41, 24105, Kiel, Germany
| | - Sönke Peters
- Department of Radiology and Neuroradiology, University Hospital Schleswig-Holstein Campus Kiel, Arnold-Heller-Straße 3, Haus 41, 24105, Kiel, Germany
| | - Catharina Drews
- Department of Radiology and Neuroradiology, University Hospital Schleswig-Holstein Campus Kiel, Arnold-Heller-Straße 3, Haus 41, 24105, Kiel, Germany
| | - Christine Gierloff
- Department of Radiology and Neuroradiology, University Hospital Schleswig-Holstein Campus Kiel, Arnold-Heller-Straße 3, Haus 41, 24105, Kiel, Germany
| | - Ulf Jensen-Kondering
- Department of Radiology and Neuroradiology, University Hospital Schleswig-Holstein Campus Kiel, Arnold-Heller-Straße 3, Haus 41, 24105, Kiel, Germany
| | - Patrick Langguth
- Department of Radiology and Neuroradiology, University Hospital Schleswig-Holstein Campus Kiel, Arnold-Heller-Straße 3, Haus 41, 24105, Kiel, Germany
| | - Jawid Madjidyar
- Department of Radiology and Neuroradiology, University Hospital Schleswig-Holstein Campus Kiel, Arnold-Heller-Straße 3, Haus 41, 24105, Kiel, Germany
| | - Tim-Christian Piesch
- Department of Radiology and Neuroradiology, University Hospital Schleswig-Holstein Campus Kiel, Arnold-Heller-Straße 3, Haus 41, 24105, Kiel, Germany
| | - Olav Jansen
- Department of Radiology and Neuroradiology, University Hospital Schleswig-Holstein Campus Kiel, Arnold-Heller-Straße 3, Haus 41, 24105, Kiel, Germany
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Martinez JA, Moulin K, Yoo B, Shi Y, Kim HJ, Villablanca PJ, Ennis DB. Evaluation of a Workflow to Define Low Specific Absorption Rate MRI Protocols for Patients With Active Implantable Medical Devices. J Magn Reson Imaging 2020; 52:91-102. [PMID: 31922311 DOI: 10.1002/jmri.27044] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2019] [Revised: 12/16/2019] [Accepted: 12/18/2019] [Indexed: 11/06/2022] Open
Abstract
BACKGROUND MRI exams for patients with MR-conditional active implantable medical devices (AIMDs) are contraindicated unless specific conditions are met. This limits the maximum specific absorption rate (SAR, W/kg). Currently, there is no general framework to guide meeting a lower SAR limit. PURPOSE To design and evaluate a workflow for modifying MRI protocols to whole-body SAR (WB-SAR ≤0.1 W/kg) and local-head SAR (LH-SAR ≤0.3 W/kg) limits while mitigating the impact on image quality and exam time. STUDY TYPE Prospective. POPULATION Twenty healthy volunteers on head (n = 5), C-spine (n = 5), T-spine (n = 5), and L-spine (n = 5) with IRB consent. ASSESSMENT Vendor-provided head, C-spine, T-spine, and L-spine protocols (SARRT ) were modified to meet both low SAR targets (SARLOW ) using the proposed workflow. in vitro SNR and CNR were evaluated with a T1 -T2 phantom. in vivo image quality and clinical acceptability were scored using a 5-point Likert scale for two blinded readers. FIELD STRENGTH/SEQUENCES 1.5T/spin-echoes, gradient-echoes. STATISTICAL ANALYSIS In vitro SNR and CNR values were evaluated with a repeated measures general linear model. in vivo image quality and clinical acceptability were evaluated using a generalized estimating equation analysis (GEE). The two reader's level of agreement was analyzed using Cohen's kappa statistical analysis. RESULTS Using the workflow, SAR limits were met. LH-SAR 0.12 ± 0.02 W/kg, median (SD) values for LH-SAR were 0.12 (0.02) W/kg and WB-SAR: 0.09 (0.01) W/kg. Examination time did not increase ≤2x the initial time. SARRT SNR values were higher and significantly different than SARLOW (P < 0.05). However, no significant difference was observed between the CNR values (value = 0.21). Median (IQR) CNR values were 14.2 (25.0) vs. 15.1 (9.2) for head, 12.1 (16.9) vs. 25.3 (14.2) for C-spine, 81.6 (70.1) vs. 71.0 (26.6) for T-spine, and 51.4 (52.6) vs. 37.7 (27.3) for L-spine. Image quality scores were not significantly different between SARRT and SARLOW (median [SD] scores were 4.0 [0.01] vs. 4.3 [0.2], P > 0.05). DATA CONCLUSION The proposed workflow provides guidance for modifying routine MRI exams to achieve low SAR limits. This can benefit patients referred for an MRI exam with low SAR MR-conditional AIMDs. LEVEL OF EVIDENCE 1 Technical Efficacy Stage: 5 J. Magn. Reson. Imaging 2020;52:91-102.
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Affiliation(s)
- Jessica A Martinez
- Department of Bioengineering, University of California, Los Angeles, California, USA.,Department of Radiological Sciences, University of California, Los Angeles, California, USA
| | - Kévin Moulin
- Department of Radiology, Stanford University, Stanford, California, USA
| | - Bryan Yoo
- Department of Radiological Sciences, University of California, Los Angeles, California, USA
| | - Yu Shi
- Department of Radiological Sciences, University of California, Los Angeles, California, USA
| | - Hyun J Kim
- Department of Radiological Sciences, University of California, Los Angeles, California, USA
| | - Pablo J Villablanca
- Department of Radiological Sciences, University of California, Los Angeles, California, USA
| | - Daniel B Ennis
- Department of Radiology, Stanford University, Stanford, California, USA
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9
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Brown MS. Regarding Off-Label Scanning of MR Conditional Devices. AJNR Am J Neuroradiol 2016; 37:2001-2002. [PMID: 27538901 DOI: 10.3174/ajnr.a4932] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Affiliation(s)
- M S Brown
- Department of Radiology University of Colorado Anschutz Medical Center Aurora, Colorado
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