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Katlowitz KA, Curry DJ, Weiner HL. Novel Surgical Approaches in Childhood Epilepsy: Laser, Brain Stimulation, and Focused Ultrasound. Adv Tech Stand Neurosurg 2024; 49:291-306. [PMID: 38700689 DOI: 10.1007/978-3-031-42398-7_13] [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] [Indexed: 06/01/2024]
Abstract
Pediatric epilepsy has a worldwide prevalence of approximately 1% (Berg et al., Handb Clin Neurol 111:391-398, 2013) and is associated with not only lower quality of life but also long-term deficits in executive function, significant psychosocial stressors, poor cognitive outcomes, and developmental delays (Schraegle and Titus, Epilepsy Behav 62:20-26, 2016; Puka and Smith, Epilepsia 56:873-881, 2015). With approximately one-third of patients resistant to medical control, surgical intervention can offer a cure or palliation to decrease the disease burden and improve neurological development. Despite its potential, epilepsy surgery is drastically underutilized. Even today only 1% of the millions of epilepsy patients are referred annually for neurosurgical evaluation, and the average delay between diagnosis of Drug Resistant Epilepsy (DRE) and surgical intervention is approximately 20 years in adults and 5 years in children (Solli et al., Epilepsia 61:1352-1364, 2020). It is still estimated that only one-third of surgical candidates undergo operative intervention (Pestana Knight et al., Epilepsia 56:375, 2015). In contrast to the stable to declining rates of adult epilepsy surgery (Englot et al., Neurology 78:1200-1206, 2012; Neligan et al., Epilepsia 54:e62-e65, 2013), rates of pediatric surgery are rising (Pestana Knight et al., Epilepsia 56:375, 2015). Innovations in surgical approaches to epilepsy not only minimize potential complications but also expand the definition of a surgical candidate. In this chapter, three alternatives to classical resection are presented. First, laser ablation provides a minimally invasive approach to focal lesions. Next, both central and peripheral nervous system stimulation can interrupt seizure networks without creating permanent lesions. Lastly, focused ultrasound is discussed as a potential new avenue not only for ablation but also modulation of small, deep foci within seizure networks. A better understanding of the potential surgical options can guide patients and providers to explore all treatment avenues.
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Affiliation(s)
- Kalman A Katlowitz
- Department of Neurosurgery, Baylor College of Medicine, Houston, TX, USA
- Department of Neurosurgery, Texas Children's Hospital, Houston, TX, USA
| | - Daniel J Curry
- Department of Neurosurgery, Baylor College of Medicine, Houston, TX, USA
- Department of Neurosurgery, Texas Children's Hospital, Houston, TX, USA
| | - Howard L Weiner
- Department of Neurosurgery, Baylor College of Medicine, Houston, TX, USA.
- Department of Neurosurgery, Texas Children's Hospital, Houston, TX, USA.
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2
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Shin DH, Son S, Kim EY. Low-Energy Transcranial Navigation-Guided Focused Ultrasound for Neuropathic Pain: An Exploratory Study. Brain Sci 2023; 13:1433. [PMID: 37891801 PMCID: PMC10605299 DOI: 10.3390/brainsci13101433] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2023] [Revised: 10/01/2023] [Accepted: 10/06/2023] [Indexed: 10/29/2023] Open
Abstract
Neuromodulation using high-energy focused ultrasound (FUS) has recently been developed for various neurological disorders, including tremors, epilepsy, and neuropathic pain. We investigated the safety and efficacy of low-energy FUS for patients with chronic neuropathic pain. We conducted a prospective single-arm trial with 3-month follow-up using new transcranial, navigation-guided, focused ultrasound (tcNgFUS) technology to stimulate the anterior cingulate cortex. Eleven patients underwent FUS with a frequency of 250 kHz and spatial-peak temporal-average intensity of 0.72 W/cm2. A clinical survey based on the visual analog scale of pain and a brief pain inventory (BPI) was performed during the study period. The average age was 60.55 ± 13.18 years-old with a male-to-female ratio of 6:5. The median current pain decreased from 10.0 to 7.0 (p = 0.021), median average pain decreased from 8.5 to 6.0 (p = 0.027), and median maximum pain decreased from 10.0 to 8.0 (p = 0.008) at 4 weeks after treatment. Additionally, the sum of daily life interference based on BPI was improved from 59.00 ± 11.66 to 51.91 ± 9.18 (p = 0.021). There were no side effects such as burns, headaches, or seizures, and no significant changes in follow-up brain magnetic resonance imaging. Low-energy tcNgFUS could be a safe and noninvasive neuromodulation technique for the treatment of chronic neuropathic pain.
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Affiliation(s)
- Dong Hoon Shin
- Department of Neurology, Gachon University Gil Medical Center, Incheon 21565, Republic of Korea;
| | - Seong Son
- Department of Neurosurgery, Gachon University Gil Medical Center, Incheon 21565, Republic of Korea;
| | - Eun Young Kim
- Department of Neurosurgery, Gachon University Gil Medical Center, Incheon 21565, Republic of Korea;
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3
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Mehta NH, Shah HA, D'Amico RS. Sonodynamic Therapy and Sonosensitizers for Glioma Treatment: A Systematic Qualitative Review. World Neurosurg 2023; 178:60-68. [PMID: 37454909 DOI: 10.1016/j.wneu.2023.07.030] [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: 03/28/2023] [Accepted: 07/07/2023] [Indexed: 07/18/2023]
Abstract
Sonodynamic therapy (SDT) has emerged as an encouraging noninvasive technique that uses ultrasound to activate targeted agents to induce antitumor effects for the treatment of glioma. With extensive variation in the types of sonosensitizers, protocols for sonication, and model systems, a comprehensive overview of existing preclinical data on the efficacy of SDT in glioma treatment is warranted. Here, we conduct a systematic review of preclinical and early clinical literature on implementing SDT to treat in vitro and in vivo models of glioma. Our findings suggest that coupling sonosensitizers such as 5-aminolevulinic acid, hematoporphyrin monomethyl ether, and sinoporphyrin sodium with focused ultrasound induces robust cytotoxic activity in tumor cells (in vitro and in vivo). These effects are likely mediated by the oxidative stress induced by reactive oxygen species production, apoptotic signaling cascades, and intracellular calcium overload. Future research is needed to better understand the biochemical and mechanistic properties of SDT, and ongoing trials may help elucidate the clinical feasibility of glioma treatment with optimized sonically activated treatments.
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Affiliation(s)
- Neel H Mehta
- Department of Biology, Cornell University, Ithaca, New York, USA.
| | - Harshal A Shah
- Department of Neurological Surgery, Lenox Hill Hospital/Donald and Barbara Zucker School of Medicine at Hofstra/ Northwell, New York, New York, USA
| | - Randy S D'Amico
- Department of Neurological Surgery, Lenox Hill Hospital/Donald and Barbara Zucker School of Medicine at Hofstra/ Northwell, New York, New York, USA
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4
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Xu L, Gong Y, Chien CY, Leuthardt E, Chen H. Transcranial focused ultrasound-induced blood‒brain barrier opening in mice without shaving hairs. Sci Rep 2023; 13:13500. [PMID: 37598243 PMCID: PMC10439893 DOI: 10.1038/s41598-023-40598-4] [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: 02/08/2023] [Accepted: 08/14/2023] [Indexed: 08/21/2023] Open
Abstract
Acoustic coupling through hairs remains a challenge to performing transcranial-focused ultrasound procedures. Here, we demonstrated that this challenge could be addressed by using oil as the coupling medium, leveraging oil's high affinity to hairs due to their inherent hydrophobicity. We compared focused ultrasound-induced blood-brain barrier opening (FUS-BBBO) outcomes in mice under three coupling conditions: oil with hairs ("oil + hairs"), ultrasound gel with hair shaving ("ultrasound gel + no hair"), and ultrasound gel with hairs ("ultrasound gel + hairs"). The quality of the coupling was evaluated by [Formula: see text]-weighted magnetic resonance imaging (MRI) and passive cavitation detection (PCD). The outcome of FUS-BBBO was assessed by MRI contrast agent extravasation using in vivo [Formula: see text]-weighted contrast-enhanced MRI. It was also evaluated by ex vivo fluorescence imaging of the mouse brain after intravenous injection of a model drug, Evans blue. The results showed that "oil + hairs" consistently achieved high-quality acoustic coupling without trapping air bubbles. The FUS-BBBO outcome was not significantly different between the "oil + hairs" and the "ultrasound gel + no hair" groups. These two groups had significantly higher levels of BBB opening than the "ultrasound gel + hairs" group. This study demonstrated that oil could be a coupling medium for transcranial FUS procedures without shaving hairs.
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Affiliation(s)
- Lu Xu
- Department of Biomedical Engineering, Washington University in St. Louis, Saint Louis, MO, 63130, USA
| | - Yan Gong
- Department of Biomedical Engineering, Washington University in St. Louis, Saint Louis, MO, 63130, USA
| | - Chih-Yen Chien
- Department of Biomedical Engineering, Washington University in St. Louis, Saint Louis, MO, 63130, USA
| | - Eric Leuthardt
- Department of Biomedical Engineering, Washington University in St. Louis, Saint Louis, MO, 63130, USA
- Department of Neurosurgery, Washington University School of Medicine, Saint Louis, MO, 63110, USA
- Center for Innovation in Neuroscience and Technology, Washington University School of Medicine, Saint Louis, MO, 63110, USA
| | - Hong Chen
- Department of Biomedical Engineering, Washington University in St. Louis, Saint Louis, MO, 63130, USA.
- Department of Neurosurgery, Washington University School of Medicine, Saint Louis, MO, 63110, USA.
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5
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Kim HC, Lee W, Weisholtz DS, Yoo SS. Transcranial focused ultrasound stimulation of cortical and thalamic somatosensory areas in human. PLoS One 2023; 18:e0288654. [PMID: 37478086 PMCID: PMC10361523 DOI: 10.1371/journal.pone.0288654] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2023] [Accepted: 06/30/2023] [Indexed: 07/23/2023] Open
Abstract
The effects of transcranial focused ultrasound (FUS) stimulation of the primary somatosensory cortex and its thalamic projection (i.e., ventral posterolateral nucleus) on the generation of electroencephalographic (EEG) responses were evaluated in healthy human volunteers. Stimulation of the unilateral somatosensory circuits corresponding to the non-dominant hand generated EEG evoked potentials across all participants; however, not all perceived stimulation-mediated tactile sensations of the hand. These FUS-evoked EEG potentials (FEP) were observed from both brain hemispheres and shared similarities with somatosensory evoked potentials (SSEP) from median nerve stimulation. Use of a 0.5 ms pulse duration (PD) sonication given at 70% duty cycle, compared to the use of 1 and 2 ms PD, elicited more distinctive FEP peak features from the hemisphere ipsilateral to sonication. Although several participants reported hearing tones associated with FUS stimulation, the observed FEP were not likely to be confounded by the auditory sensation based on a separate measurement of auditory evoked potentials (AEP) to tonal stimulation (mimicking the same repetition frequency as the FUS stimulation). Off-line changes in resting-state functional connectivity (FC) associated with thalamic stimulation revealed that the FUS stimulation enhanced connectivity in a network of sensorimotor and sensory integration areas, which lasted for at least more than an hour. Clinical neurological evaluations, EEG, and neuroanatomical MRI did not reveal any adverse or unintended effects of sonication, attesting its safety. These results suggest that FUS stimulation may induce long-term neuroplasticity in humans, indicating its neurotherapeutic potential for various neurological and neuropsychiatric conditions.
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Affiliation(s)
- Hyun-Chul Kim
- Department of Radiology, Brigham and Women's Hospital, Harvard Medical School, Boston, Massachusetts, United States of America
| | - Wonhye Lee
- Department of Radiology, Brigham and Women's Hospital, Harvard Medical School, Boston, Massachusetts, United States of America
| | - Daniel S Weisholtz
- Department of Neurology, Brigham and Women's Hospital, Harvard Medical School, Boston, Massachusetts, United States of America
| | - Seung-Schik Yoo
- Department of Radiology, Brigham and Women's Hospital, Harvard Medical School, Boston, Massachusetts, United States of America
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Brinker ST, Yoon K, Benveniste H. Global sonication of the human intracranial space via a jumbo planar transducer. ULTRASONICS 2023; 134:107062. [PMID: 37343366 DOI: 10.1016/j.ultras.2023.107062] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/24/2023] [Revised: 05/25/2023] [Accepted: 05/30/2023] [Indexed: 06/23/2023]
Abstract
Contrary to conditioning a Focused Ultrasound (FUS) beam to sonicate a localized region of the human brain, the goal of this investigation was to explore the prospect of distributing homogeneous ultrasound energy over the entire brain space with a large cranium-wide ultrasound beam. Recent ultrasound preclincal studies utilizing large or whole brain stimulation regions create a demand for expanding the treatment envelope of transcranial pulsed-low intensity ultrasound towards Global Brain Sonication (GBS) for potential human investigation. Here, we conduct ultrasound field characterizations when transmitting pulsed ultrasound through human skull specimens using a 1-3 piezocomposite planar transducer operating at 464 kHz with an active single-element surface of 30 × 30 cm. Through computational simulation and hydrophone scanning methodology, ultrasound wave behavior and dose homogeneity in the brain space were evaluated under various trajectories of sonication using the planar transducer. Clinically relevant pulse parameters used for transcranial therapeutic ultrasound applications were used in the experiments. Simulations and empirical testing revealed that dose homogeneity and acoustic intensity over the brain space are influenced by sonication trajectory, skull lens effects, and acoustic wave reflections. The transducer can emit a spatial peak pulse average intensity of 4.03 W/cm2 (0.24 MPa) measured in the free-field at 464 kHz with electrical power of 1 kW. The simulation showed that approximately 99 % of the cranial volume was exposed with <30 % of the maximum external acoustic intensity being transmitted into the skull. The transmission loss across all sonication trajectories is similar to previously reported FUS studies. A marker for GBS dose homogeneity is introduced to score the ultrasound pressure field uniformity in the intracranial space. Results of this study identify the initial challenges of exposing the entire human brain space with ultrasound using a large cranium-wide sonication beam intended for global brain therapeutic modulation.
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Affiliation(s)
- Spencer T Brinker
- Department of Anesthesiology, Yale School of Medicine, New Haven, CT, USA.
| | - Kyungho Yoon
- School of Mathematics and Computing (Computational Science and Engineering), Yonsei University, Seoul, South Korea
| | - Helene Benveniste
- Department of Anesthesiology, Yale School of Medicine, New Haven, CT, USA
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Attali D, Tiennot T, Schafer M, Fouragnan E, Sallet J, Caskey CF, Chen R, Darmani G, Bubrick EJ, Butler C, Stagg CJ, Klein-Flügge M, Verhagen L, Yoo SS, Pauly KB, Aubry JF. Three-layer model with absorption for conservative estimation of the maximum acoustic transmission coefficient through the human skull for transcranial ultrasound stimulation. Brain Stimul 2023; 16:48-55. [PMID: 36549480 DOI: 10.1016/j.brs.2022.12.005] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2022] [Revised: 12/05/2022] [Accepted: 12/12/2022] [Indexed: 12/23/2022] Open
Abstract
Transcranial ultrasound stimulation (TUS) has been shown to be a safe and effective technique for non-invasive superficial and deep brain stimulation. Safe and efficient translation to humans requires estimating the acoustic attenuation of the human skull. Nevertheless, there are no international guidelines for estimating the impact of the skull bone. A tissue independent, arbitrary derating was developed by the U.S. Food and Drug Administration to take into account tissue absorption (0.3 dB/cm-MHz) for diagnostic ultrasound. However, for the case of transcranial ultrasound imaging, the FDA model does not take into account the insertion loss induced by the skull bone, nor the absorption by brain tissue. Therefore, the estimated absorption is overly conservative which could potentially limit TUS applications if the same guidelines were to be adopted. Here we propose a three-layer model including bone absorption to calculate the maximum pressure transmission through the human skull for frequencies ranging between 100 kHz and 1.5 MHz. The calculated pressure transmission decreases with the frequency and the thickness of the bone, with peaks for each thickness corresponding to a multiple of half the wavelength. The 95th percentile maximum transmission was calculated over the accessible surface of 20 human skulls for 12 typical diameters of the ultrasound beam on the skull surface, and varies between 40% and 78%. To facilitate the safe adjustment of the acoustic pressure for short ultrasound pulses, such as transcranial imaging or transcranial ultrasound stimulation, a table summarizes the maximum pressure transmission for each ultrasound beam diameter and each frequency.
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Affiliation(s)
- David Attali
- Physics for Medicine Paris, Inserm U1273, ESPCI Paris, CNRS UMR8063, PSL University, Paris, France; Pôle Paris 16 (Secteurs 17-18) et Pôle Neuro Sainte-Anne, Centre Hospitalier Sainte-Anne, GHU Paris Psychiatrie & Neurosciences, Université Paris Cité, Paris, France
| | - Thomas Tiennot
- Physics for Medicine Paris, Inserm U1273, ESPCI Paris, CNRS UMR8063, PSL University, Paris, France
| | - Mark Schafer
- School of Biomedical Engineering, Science and Health Systems, Drexel University, Philadelphia, PA, USA
| | - Elsa Fouragnan
- Brain Research Imaging Center and School of Psychology, University of Plymouth, Plymouth, UK; School of Psychology, Portland Square, Plymouth PL4 8AA, UK
| | - Jérôme Sallet
- Univ Lyon, Université Lyon 1, Inserm, Stem Cell and Brain Research Institute U1208, Bron, France
| | - Charles F Caskey
- Vanderbilt University Institute of Imaging Sciences, VU Medical Center, Nashville, TN, United States
| | - Robert Chen
- Division of Neurology, Department of Medicine, University of Toronto, Canada; Krembil Research Institute, University Health Network, Toronto, Ontario, Canada
| | - Ghazaleh Darmani
- Krembil Research Institute, University Health Network, Toronto, Ontario, Canada
| | - Ellen J Bubrick
- Brigham and Women's Hospital, Harvard Medical School, Department of Neurology, 75 Francis St., Boston, MA, USA
| | - Christopher Butler
- Department of Brain Sciences, Imperial College London, 9th Floor, Sir Michael Uren Hub, 86 Wood Lane, London, W12 0BZ, UK
| | - Charlotte J Stagg
- Wellcome Centre for Integrative Neuroimaging (WIN), Centre for Functional MRI of the Brain (FMRIB), University of Oxford, Nuffield Department of Clinical Neurosciences, Level 6, West Wing, John Radcliffe Hospital, Oxford OX3 9DU, UK
| | - Miriam Klein-Flügge
- Wellcome Centre for Integrative Neuroimaging (WIN), Centre for Functional MRI of the Brain (FMRIB), University of Oxford, Nuffield Department of Clinical Neurosciences, Level 6, West Wing, John Radcliffe Hospital, Oxford OX3 9DU, UK; Wellcome Centre for Integrative Neuroimaging (WIN), Department of Experimental Psychology, University of Oxford, Tinsley Building, Mansfield Road, Oxford OX1 3TA, UK
| | - Lennart Verhagen
- Donders Institute for Brain, Cognition and Behaviour, Radboud University, 6525 GD Nijmegen, the Netherlands
| | - Seung-Schik Yoo
- Brigham and Women's Hospital, Harvard Medical School, Department of Radiology, 75 Francis St., Boston, MA, USA
| | - Kim Butts Pauly
- Stanford University, Department of Radiology, Stanford CA, 94305, USA
| | - Jean-Francois Aubry
- Physics for Medicine Paris, Inserm U1273, ESPCI Paris, CNRS UMR8063, PSL University, Paris, France.
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Riis TS, Webb TD, Kubanek J. Acoustic properties across the human skull. ULTRASONICS 2022; 119:106591. [PMID: 34717144 PMCID: PMC8642838 DOI: 10.1016/j.ultras.2021.106591] [Citation(s) in RCA: 22] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/19/2021] [Revised: 08/05/2021] [Accepted: 09/16/2021] [Indexed: 05/11/2023]
Abstract
Transcranial ultrasound is emerging as a noninvasive tool for targeted treatments of brain disorders. Transcranial ultrasound has been used for remotely mediated surgeries, transient opening of the blood-brain barrier, local drug delivery, and neuromodulation. However, all applications have been limited by the severe attenuation and phase distortion of ultrasound by the skull. Here, we characterized the dependence of the aberrations on specific anatomical segments of the skull. In particular, we measured ultrasound propagation properties throughout the perimeter of intact human skulls at 500 kHz. We found that the parietal bone provides substantially higher transmission (average pressure transmission 31 ± 7%) and smaller phase distortion (242 ± 44 degrees) than frontal (13 ± 2%, 425 ± 47 degrees) and occipital bone regions (16 ± 4%, 416 ± 35 degrees). In addition, we found that across skull regions, transmission strongly anti-correlated (R=-0.79) and phase distortion correlated (R=0.85) with skull thickness. This information guides the design, positioning, and skull correction functionality of next-generation devices for effective, safe, and reproducible transcranial focused ultrasound therapies.
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Affiliation(s)
- Thomas S Riis
- Department of Biomedical Engineering, University of Utah, Salt Lake City, 84112, UT, United States.
| | - Taylor D Webb
- Department of Biomedical Engineering, University of Utah, Salt Lake City, 84112, UT, United States.
| | - Jan Kubanek
- Department of Biomedical Engineering, University of Utah, Salt Lake City, 84112, UT, United States.
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Spivak NM, Sanguinetti JL, Monti MM. Focusing in on the Future of Focused Ultrasound as a Translational Tool. Brain Sci 2022; 12:brainsci12020158. [PMID: 35203922 PMCID: PMC8870102 DOI: 10.3390/brainsci12020158] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2021] [Revised: 01/14/2022] [Accepted: 01/22/2022] [Indexed: 12/22/2022] Open
Abstract
This article summarizes the field of focused ultrasound for use in neuromodulation and discusses different ways of targeting, delivering, and validating focused ultrasound. A discussion is focused on parameter space and different ongoing theories of ultrasonic neuromodulation. Current and future applications of the technique are discussed.
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Affiliation(s)
- Norman M. Spivak
- UCLA—Caltech Medical Scientist Training Program, David Geffen School of Medicine, Los Angeles, CA 90095, USA
- Department of Neurosurgery, University of California, Los Angeles, CA 90095, USA;
- Department of Psychiatry and Biobehavioral Sciences, University of California, Los Angeles, CA 90095, USA
- Correspondence:
| | - Joseph L. Sanguinetti
- Department of Psychology, University of Arizona, Tucson, AZ 85721, USA;
- Department of Psychology, University of New Mexico, Albuquerque, NM 87131, USA
| | - Martin M. Monti
- Department of Neurosurgery, University of California, Los Angeles, CA 90095, USA;
- Department of Psychiatry and Biobehavioral Sciences, University of California, Los Angeles, CA 90095, USA
- Department of Psychology, University of California, Los Angeles, CA 90095, USA
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Bancel T, Tiennot T, Aubry JF. Adaptive Ultrasound Focusing Through the Cranial Bone for Non-invasive Treatment of Brain Disorders. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2022; 1364:397-409. [DOI: 10.1007/978-3-030-91979-5_18] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
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11
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Yang AI, Hitti FL, Alabi OO, Joshi D, Chaibainou H, Henry L, Clanton R, Baltuch GH. Patient-specific effects on sonication heating efficiency during magnetic resonance-guided focused ultrasound thalamotomy. Med Phys 2021; 48:6588-6596. [PMID: 34532858 DOI: 10.1002/mp.15239] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2021] [Revised: 09/07/2021] [Accepted: 09/07/2021] [Indexed: 01/09/2023] Open
Abstract
PURPOSE During magnetic resonance-guided focused ultrasound (MRgFUS) thalamotomy for refractory tremor, high temperatures must be achieved and sustained for tissue necrosis. We assessed the impact of both patient-specific as well as procedure-related factors on the efficiency of acoustic energy transfer, or heating efficiency (HE). METHODS Retrospective analysis of 92 consecutive patients (857 sonications) with essential tremor or tremor-dominant Parkinson's disease treated at a single institution. Temperature elevations at the target were measured for each sonication with MR thermometry. HE of each sonication was defined as the ratio of peak temperature elevation and the delivered energy. HE was analyzed with respect to patient skull features (area, thickness, skull density ratio [SDR]), computed from CT scans, as well as demographic and clinical variables (age, sex, diagnosis, and duration of symptoms). RESULTS Across the full range of sonication energies that can be delivered with current devices (up to 36 kJ), average sonication HE was diminished in patients with lower SDR. In individual subjects, there was a progressive loss in HE as sonication energy was titrated up throughout the course of treatment, with a more rapid decline in patients with higher SDR. This energy-dependent loss in HE was not related to procedural factors, namely, the number of previous sonications, or the cumulative energy deposited during previous sonications. In contrast to SDR, neither skull area nor thickness was an independent predictor of average HE or the rate of its decline with increasing energies. In 11% of patients, all of whom with SDR < 0.45, sonication HE fell below the threshold to reach 54°C even with delivery of maximum energy. In contrast, temperatures ≥ 50°C could be obtained in all but one patient. CONCLUSIONS SDR is predictive of sonication HE, and determines patient-specific limits on the magnitude of temperature elevation that can be achieved with current devices. These data inform strategies for predictable lesioning in MRgFUS thalamotomy.
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Affiliation(s)
- Andrew I Yang
- Department of Neurosurgery, University of Pennsylvania, Philadelphia, Pennsylvania, USA
| | - Frederick L Hitti
- Department of Neurosurgery, University of Pennsylvania, Philadelphia, Pennsylvania, USA
| | - Opeyemi O Alabi
- Department of Neurosurgery, University of Pennsylvania, Philadelphia, Pennsylvania, USA
| | - Disha Joshi
- Department of Neurosurgery, University of Pennsylvania, Philadelphia, Pennsylvania, USA
| | - Hanane Chaibainou
- Department of Neurosurgery, University of Pennsylvania, Philadelphia, Pennsylvania, USA
| | | | | | - Gordon H Baltuch
- Department of Neurosurgery, University of Pennsylvania, Philadelphia, Pennsylvania, USA
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12
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Lu N, Hall TL, Choi D, Gupta D, Daou BJ, Sukovich JR, Fox A, Gerhardson TI, Pandey AS, Noll DC, Xu Z. Transcranial MR-Guided Histotripsy System. IEEE TRANSACTIONS ON ULTRASONICS, FERROELECTRICS, AND FREQUENCY CONTROL 2021; 68:2917-2929. [PMID: 33755563 PMCID: PMC8428576 DOI: 10.1109/tuffc.2021.3068113] [Citation(s) in RCA: 21] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/05/2023]
Abstract
Histotripsy has been previously shown to treat a wide range of locations through excised human skulls in vitro. In this article, a transcranial magnetic resonance (MR)-guided histotripsy (tcMRgHt) system was developed, characterized, and tested in the in vivo pig brain through an excised human skull. A 700-kHz, 128-element MR-compatible phased-array ultrasound transducer with a focal depth of 15 cm was designed and fabricated in-house. Support structures were also constructed to facilitate transcranial treatment. The tcMRgHt array was acoustically characterized with a peak negative pressure up to 137 MPa in free field, 72 MPa through an excised human skull with aberration correction, and 48.4 MPa without aberration correction. The electronic focal steering range through the skull was 33.5 mm laterally and 50 mm axially, where a peak negative pressure above the 26-MPa cavitation intrinsic threshold can be achieved. The MR compatibility of the tcMRgHt system was assessed quantitatively using SNR, B0 field map, and B1 field map in a clinical 3T magnetic resonance imaging (MRI) scanner. Transcranial treatment using electronic focal steering was validated in red blood cell phantoms and in vivo pig brain through an excised human skull. In two pigs, targeted cerebral tissue was successfully treated through the human skull as confirmed by MRI. Excessive bleeding or edema was not observed in the peri-target zones by the time of pig euthanasia. These results demonstrated the feasibility of using this preclinical tcMRgHt system for in vivo transcranial treatment in a swine model.
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13
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Miao YB, Chen KH, Chen CT, Mi FL, Lin YJ, Chang Y, Chiang CS, Wang JT, Lin KJ, Sung HW. A Noninvasive Gut-to-Brain Oral Drug Delivery System for Treating Brain Tumors. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2021; 33:e2100701. [PMID: 34270814 DOI: 10.1002/adma.202100701] [Citation(s) in RCA: 24] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/27/2021] [Revised: 04/06/2021] [Indexed: 06/13/2023]
Abstract
Most orally administered drugs fail to reach the intracerebral regions because of the intestinal epithelial barrier (IEB) and the blood-brain barrier (BBB), which are located between the gut and the brain. Herein, an oral prodrug delivery system that can overcome both the IEB and the BBB noninvasively is developed for treating gliomas. The prodrug is prepared by conjugating an anticancer drug on β-glucans using a disulfide-containing linker. Following oral administration in glioma-bearing mice, the as-prepared prodrug can specifically target intestinal M cells, transpass the IEB, and be phagocytosed/hitchhiked by local macrophages (Mϕ). The Mϕ-hitchhiked prodrug is transported to the circulatory system via the lymphatic system, crossing the BBB. The tumor-overexpressed glutathione then cleaves the disulfide bond within the prodrug, releasing the active drug, improving its therapeutic efficacy. These findings reveal that the developed prodrug may serve as a gut-to-brain oral drug delivery platform for the well-targeted treatment of gliomas.
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Affiliation(s)
- Yang-Bao Miao
- Department of Chemical Engineering and Frontier Research Center on Fundamental and Applied Sciences of Matters, National Tsing Hua University, Hsinchu, 30013, Taiwan
| | - Kuan-Hung Chen
- Department of Chemical Engineering and Frontier Research Center on Fundamental and Applied Sciences of Matters, National Tsing Hua University, Hsinchu, 30013, Taiwan
| | - Chiung-Tong Chen
- Institute of Biotechnology and Pharmaceutical Research, National Health Research Institutes, Zhunan, Miaoli, 35053, Taiwan
| | - Fwu-Long Mi
- Department of Biochemistry and Molecular Cell Biology, School of Medicine, College of Medicine, Taipei Medical University, Taipei, 23142, Taiwan
| | - Yu-Jung Lin
- Research Center for Applied Sciences, Academia Sinica, Taipei, 11529, Taiwan
| | - Yen Chang
- Taipei Tzu Chi Hospital, Buddhist Tzu Chi Medical Foundation and School of Medicine, Tzu Chi University, Hualien, 97004, Taiwan
| | - Chi-Shiun Chiang
- Department of Biomedical Engineering and Environmental Sciences, National Tsing Hua University, Hsinchu, 30013, Taiwan
| | - Jui-To Wang
- Neurological Institute, Department of Neurosurgery, Taipei Veterans General Hospital, Taipei, 11217, Taiwan
- Institute of Brain Science, National Yang-Ming University, Taipei, 11221, Taiwan
| | - Kun-Ju Lin
- Department of Nuclear Medicine and Molecular Imaging Center, Linkou Chang Gung Memorial Hospital, and Department of Medical Imaging and Radiological Sciences, Chang Gung University, Taoyuan, 33302, Taiwan
| | - Hsing-Wen Sung
- Department of Chemical Engineering and Frontier Research Center on Fundamental and Applied Sciences of Matters, National Tsing Hua University, Hsinchu, 30013, Taiwan
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14
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Cranial MR-Guided Focused Ultrasound: Clinical Challenges and Future Directions. World Neurosurg 2021; 145:574-580. [PMID: 33348523 DOI: 10.1016/j.wneu.2020.08.050] [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: 04/28/2020] [Accepted: 07/01/2020] [Indexed: 11/21/2022]
Abstract
Magnetic resonance-guided focused ultrasound is a powerful new technology that is enabling development of noninvasive applications for complex brain disorders. This is currently revolutionizing the treatment of tremor disorders, and a variety of experimental applications are under active investigation. To fully realize the potential of this disruptive technology, many challenges have been identified, some of which have been addressed and others remain to be solved. As an image-based technology, optimal intraoperative imaging can be difficult to achieve and several factors can influence the quality of these images. Technical issues with current devices can also limit the effective delivery of ultrasound technology to particular targets. While lesioning is the primary approved application of magnetic resonance-guided focused ultrasound at present, the ability to transient and precisely open the blood-brain barrier has the potential to clear brain pathologies and deliver restorative therapies, but this more experimental method presents unique difficulties to overcome. Finally, regulatory and reimbursement hurdles currently remain complex and continue to limit widespread application of even approved, effective applications. Here we review many of these challenges, discuss several solutions that have already been developed, and propose potential options for addressing some of these complexities in the future.
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15
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Qiu W, Bouakaz A, Konofagou EE, Zheng H. Ultrasound for the Brain: A Review of Physical and Engineering Principles, and Clinical Applications. IEEE TRANSACTIONS ON ULTRASONICS, FERROELECTRICS, AND FREQUENCY CONTROL 2021; 68:6-20. [PMID: 32866096 DOI: 10.1109/tuffc.2020.3019932] [Citation(s) in RCA: 29] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
The emergence of new ultrasound technologies has improved our understanding of the brain functions and offered new opportunities for the treatment of brain diseases. Ultrasound has become a valuable tool in preclinical animal and clinical studies as it not only provides information about the structure and function of brain tissues but can also be used as a therapy alternative for brain diseases. High-resolution cerebral flow images with high sensitivity can be acquired using novel functional ultrasound and super-resolution ultrasound imaging techniques. The noninvasive treatment of essential tremors has been clinically approved and it has been demonstrated that the ultrasound technology can revolutionize the currently existing treatment methods. Microbubble-mediated ultrasound can remotely open the blood-brain barrier enabling targeted drug delivery in the brain. More recently, ultrasound neuromodulation received a great amount of attention due to its noninvasive and deep penetration features and potential therapeutic benefits. This review provides a thorough introduction to the current state-of-the-art research on brain ultrasound and also introduces basic knowledge of brain ultrasound including the acoustic properties of the brain/skull and engineering techniques for ultrasound. Ultrasound is expected to play an increasingly important role in the diagnosis and therapy of brain diseases.
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16
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Meng Y, Jones RM, Davidson B, Huang Y, Pople CB, Surendrakumar S, Hamani C, Hynynen K, Lipsman N. Technical Principles and Clinical Workflow of Transcranial MR-Guided Focused Ultrasound. Stereotact Funct Neurosurg 2020; 99:329-342. [PMID: 33302282 DOI: 10.1159/000512111] [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: 07/21/2020] [Accepted: 09/28/2020] [Indexed: 11/19/2022]
Abstract
Transcranial MR-guided focused ultrasound (MRgFUS) is a rapidly developing technology in neuroscience for manipulating brain structure and function without open surgery. The effectiveness of transcranial MRgFUS for thermoablation is well established, and the technique is actively employed worldwide for movement disorders including essential tremor. A growing number of centers are also investigating the potential of microbubble-mediated focused ultrasound-induced opening of the blood-brain barrier (BBB) for targeted drug delivery to the brain. Here, we provide a technical overview of the principles, clinical workflow, and operator considerations of transcranial MRgFUS procedures for both thermoablation and BBB opening.
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Affiliation(s)
- Ying Meng
- Sunnybrook Research Institute, University of Toronto, Toronto, Ontario, Canada.,Division of Neurosurgery, Department of Surgery, University of Toronto, Toronto, Ontario, Canada
| | - Ryan M Jones
- Sunnybrook Research Institute, University of Toronto, Toronto, Ontario, Canada
| | - Benjamin Davidson
- Sunnybrook Research Institute, University of Toronto, Toronto, Ontario, Canada.,Division of Neurosurgery, Department of Surgery, University of Toronto, Toronto, Ontario, Canada
| | - Yuexi Huang
- Sunnybrook Research Institute, University of Toronto, Toronto, Ontario, Canada
| | - Christopher B Pople
- Sunnybrook Research Institute, University of Toronto, Toronto, Ontario, Canada
| | | | - Clement Hamani
- Sunnybrook Research Institute, University of Toronto, Toronto, Ontario, Canada.,Division of Neurosurgery, Department of Surgery, University of Toronto, Toronto, Ontario, Canada
| | - Kullervo Hynynen
- Sunnybrook Research Institute, University of Toronto, Toronto, Ontario, Canada.,Department of Medical Biophysics, University of Toronto, Toronto, Ontario, Canada.,Institute of Biomedical Engineering, University of Toronto, Toronto, Ontario, Canada
| | - Nir Lipsman
- Sunnybrook Research Institute, University of Toronto, Toronto, Ontario, Canada, .,Division of Neurosurgery, Department of Surgery, University of Toronto, Toronto, Ontario, Canada,
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17
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Constans C, Ahnine H, Santin M, Lehericy S, Tanter M, Pouget P, Aubry JF. Non-invasive ultrasonic modulation of visual evoked response by GABA delivery through the blood brain barrier. J Control Release 2020; 318:223-231. [DOI: 10.1016/j.jconrel.2019.12.006] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2019] [Revised: 10/25/2019] [Accepted: 12/05/2019] [Indexed: 11/25/2022]
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18
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Blackmore J, Shrivastava S, Sallet J, Butler CR, Cleveland RO. Ultrasound Neuromodulation: A Review of Results, Mechanisms and Safety. ULTRASOUND IN MEDICINE & BIOLOGY 2019; 45:1509-1536. [PMID: 31109842 PMCID: PMC6996285 DOI: 10.1016/j.ultrasmedbio.2018.12.015] [Citation(s) in RCA: 228] [Impact Index Per Article: 45.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/06/2018] [Revised: 12/13/2018] [Accepted: 12/29/2018] [Indexed: 05/03/2023]
Abstract
Ultrasonic neuromodulation is a rapidly growing field, in which low-intensity ultrasound (US) is delivered to nervous system tissue, resulting in transient modulation of neural activity. This review summarizes the findings in the central and peripheral nervous systems from mechanistic studies in cell culture to cognitive behavioral studies in humans. The mechanisms by which US mechanically interacts with neurons and could affect firing are presented. An in-depth safety assessment of current studies shows that parameters for the human studies fall within the safety envelope for US imaging. Challenges associated with accurately targeting US and monitoring the response are described. In conclusion, the literature supports the use of US as a safe, non-invasive brain stimulation modality with improved spatial localization and depth targeting compared with alternative methods. US neurostimulation has the potential to be used both as a scientific instrument to investigate brain function and as a therapeutic modality to modulate brain activity.
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Affiliation(s)
- Joseph Blackmore
- Institute of Biomedical Engineering, Department of Engineering Science, University of Oxford, Roosevelt Drive, Oxford, UK
| | - Shamit Shrivastava
- Institute of Biomedical Engineering, Department of Engineering Science, University of Oxford, Roosevelt Drive, Oxford, UK
| | - Jerome Sallet
- Wellcome Centre for Integrative Nueroimaging, Department of Experimental Psychology, University of Oxford, Oxford, UK
| | - Chris R Butler
- Nuffield Department of Clinical Neurosciences, John Radcliffe Hospital, Oxford, UK
| | - Robin O Cleveland
- Institute of Biomedical Engineering, Department of Engineering Science, University of Oxford, Roosevelt Drive, Oxford, UK.
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19
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di Biase L, Falato E, Di Lazzaro V. Transcranial Focused Ultrasound (tFUS) and Transcranial Unfocused Ultrasound (tUS) Neuromodulation: From Theoretical Principles to Stimulation Practices. Front Neurol 2019; 10:549. [PMID: 31244747 PMCID: PMC6579808 DOI: 10.3389/fneur.2019.00549] [Citation(s) in RCA: 78] [Impact Index Per Article: 15.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2019] [Accepted: 05/07/2019] [Indexed: 01/28/2023] Open
Abstract
Transcranial focused ultrasound is an emerging technique for non-invasive neurostimulation. Compared to magnetic or electric non-invasive brain stimulation, this technique has a higher spatial resolution and can reach deep structures. In addition, both animal and human studies suggest that, potentially, different sites of the central and peripheral nervous system can be targeted by this technique. Depending on stimulation parameters, transcranial focused ultrasound is able to determine a wide spectrum of effects, ranging from suppression or facilitation of neural activity to tissue ablation. The aim is to review the state of the art of the human transcranial focused ultrasound neuromodulation literature, including the theoretical principles which underlie the explanation of the bioeffects on neural tissues, and showing the stimulation techniques and parameters used and their outcomes in terms of clinical, neurophysiological or neuroimaging results and safety.
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Affiliation(s)
- Lazzaro di Biase
- Neurology, Neurophysiology, and Neurobiology Unit, Department of Medicine, Campus Bio-Medico University of Rome, Rome, Italy.,Unit of Neurophysiology and Neuroengineering of Human-Technology Interaction, School of Medicine, Campus Bio-Medico University of Rome, Rome, Italy
| | - Emma Falato
- Neurology, Neurophysiology, and Neurobiology Unit, Department of Medicine, Campus Bio-Medico University of Rome, Rome, Italy.,Unit of Neurophysiology and Neuroengineering of Human-Technology Interaction, School of Medicine, Campus Bio-Medico University of Rome, Rome, Italy
| | - Vincenzo Di Lazzaro
- Neurology, Neurophysiology, and Neurobiology Unit, Department of Medicine, Campus Bio-Medico University of Rome, Rome, Italy
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20
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Maimbourg G, Houdouin A, Deffieux T, Tanter M, Aubry JF. Steering Capabilities of an Acoustic Lens for Transcranial Therapy: Numerical and Experimental Studies. IEEE Trans Biomed Eng 2019; 67:27-37. [PMID: 30932823 DOI: 10.1109/tbme.2019.2907556] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
For successful brain therapy, transcranial focused ultrasound must compensate for the time shifts induced locally by the skull. The patient-specific phase profile is currently generated by multi-element arrays which, over time, have tended toward increasing element count. We recently introduced a new approach, consisting of a single-element transducer coupled to an acoustic lens of controlled thickness. By adjusting the local thickness of the lens, we were able to induce phase differences which compensated those induced by the skull. Nevertheless, such an approach suffers from an apparent limitation: the lens is a priori designed for one specific target. In this paper, we demonstrate the possibility of taking advantage of the isoplanatic angle of the aberrating skull in order to steer the focus by mechanically moving the transducer/acoustic lens pair around its initial focusing position. This study, conducted on three human skull samples, demonstrates that tilting of the transducer with the lens restores a single -3 dB focal volume at 914 kHz for a steering up to ±11 mm in the transverse direction, and ±10 mm in the longitudinal direction, around the initial focal region.
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21
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Brinker ST, Crake C, Ives JR, Bubrick EJ, McDannold NJ. Scalp sensor for simultaneous acoustic emission detection and electroencephalography during transcranial ultrasound. Phys Med Biol 2018; 63:155017. [PMID: 29968579 PMCID: PMC6190699 DOI: 10.1088/1361-6560/aad0c2] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
Focused ultrasound is now capable of noninvasively penetrating the intact human skull and delivering energy to specific areas of the brain with millimeter accuracy. The ultrasound energy is supplied in high-intensities to create brain lesions or at low-intensities to produce reversible physiological interventions. Conducting acoustic emission detection (AED) and electroencephalography (EEG) during transcranial focused ultrasound may lead to several new brain treatment and research applications. This study investigates the feasibility of using a novel scalp senor for acquiring concurrent AED and EEG during clinical transcranial ultrasound. A piezoelectric disk is embedded in a plastic cup EEG electrode to form the sensor. The sensor is coupled to the head via an adhesive/conductive gel-dot. Components of the sensor prototype are tested for AED and EEG signal quality in a bench top investigation with a functional ex vivo skull phantom.
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Affiliation(s)
- Spencer T Brinker
- Department of Radiology, Brigham and Women's Hospital, Harvard Medical School, Boston, MA, United States of America
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22
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Maimbourg G, Houdouin A, Santin M, Lehericy S, Tanter M, Aubry JF. Inside/outside the brain binary cavitation localization based on the lowpass filter effect of the skull on the harmonic content: a proof of concept study. Phys Med Biol 2018; 63:135012. [PMID: 29864024 DOI: 10.1088/1361-6560/aaca21] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Abstract
Cavitation activity induced by ultrasound may occur during high intensity focused ultrasound (HIFU) treatment, due to bubble nucleation under high peak negative pressure, and during blood-brain-barrier (BBB) disruption, due to injected ultrasound contrast agents (UCAs). Such microbubble activity has to be monitored to assess the safety and efficiency of ultrasonic brain treatments. In this study, we aim at assessing whether cavitation occurs within cerebral tissue by binary discriminating cavitation activity originating from the inside or the outside of the skull. The results were obtained from both in vitro experiments mimicking BBB opening, by using UCA flow, and in vitro thermal necrosis in calf brain samples. The sonication was applied using a 1 MHz focused transducer and the acoustic response of the microbubbles was recorded with a wideband passive cavitation detector. The spectral content of the recorded signal was used to localize microbubble activity. Since the skull acts as a low pass filter, the ratio of high harmonics to low harmonics is lower for cavitation events located inside the skull compared to events outside the skull. Experiments showed that the ratio of the 5/2 ultraharmonic to the 1/2 subharmonic for binary localization cavitation activity achieves 100% sensitivity and specificity for both monkey and human skulls. The harmonic ratio of the fourth to the second harmonic provided 100% sensitivity and 96% and 46% specificity on a non-human primate for thermal necrosis and BBB opening, respectively. Nonetheless, the harmonic ratio remains promising for human applications, as the experiments showed 100% sensitivity and 100% specificity for both thermal necrosis and BBB opening through the human skull. The study requires further validation on a larger number of skull samples.
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Affiliation(s)
- Guillaume Maimbourg
- Institut Langevin, ESPCI Paris, CNRS UMR7587, INSERM U 979, F-75012, PSL Research University, Paris, France. Université Paris Diderot, Sorbonne Paris Cité, F-75013, Paris, France
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23
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Hughes A, Huang Y, Schwartz ML, Hynynen K. The reduction in treatment efficiency at high acoustic powers during MR-guided transcranial focused ultrasound thalamotomy for Essential Tremor. Med Phys 2018; 45:2925-2936. [PMID: 29758099 DOI: 10.1002/mp.12975] [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: 01/05/2018] [Revised: 05/07/2018] [Accepted: 05/07/2018] [Indexed: 12/19/2022] Open
Abstract
PURPOSE To analyze clinical data indicating a reduction in the induced energy-temperature efficiency relationship during transcranial focused ultrasound (FUS) Essential Tremor (ET) thalamotomy treatments at higher acoustic powers, establish its relationship with the spatial distribution of the focal temperature elevation, and explore its cause. METHODS A retrospective observational study of patients (n = 19) treated between July 2015 and August 2016 for (ET) by FUS thalamotomy was performed. These data were analyzed to compare the relationships between the applied power, the applied energy, the resultant peak temperature achieved in the brain, and the dispersion of the focal volume. Full ethics approval was received and all patients provided signed informed consent forms before the initiation of the study. Computer simulations, animal experiments, and clinical system tests were performed to determine the effects of skull heating, changes in brain properties and transducer acoustic output, respectively. All animal procedures were approved by the Animal Care and Use Committee and conformed to the guidelines set out by the Canadian Council on Animal Care. MATLAB was used to perform statistical analysis. RESULTS The reduction in the energy efficiency relationship during treatment correlates with the increase in size of the focal volume at higher sonication powers. A linear relationship exists showing that a decrease in treatment efficiency correlates positively with an increase in the focal size over the course of treatment (P < 0.01), supporting the hypothesis of transient skull and tissue heating causing acoustic aberrations leading to a decrease in efficiency. Changes in thermal conductivity, perfusion, absorption rates in the brain, as well as ultrasound transducer acoustic output levels were found to have minimal effects on the observed reduction in efficiency. CONCLUSIONS The reduction in energy-temperature efficiency during high-power FUS treatments correlated with observed increases in the size of the focal volume and is likely caused by transient changes in the tissue and skull during heating.
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Affiliation(s)
- Alec Hughes
- Department of Medical Biophysics, University of Toronto, 101 College St, Room 15-701, Toronto, Canada.,Physical Sciences Platform, Sunnybrook Research Institute, Room C713, 2075 Bayview Ave, Toronto, Canada
| | - Yuexi Huang
- Physical Sciences Platform, Sunnybrook Research Institute, Room C713, 2075 Bayview Ave, Toronto, Canada
| | - Michael L Schwartz
- Division of Neurosurgery, Department of Surgery, Sunnybrook Health Sciences Centre, Toronto, Canada
| | - Kullervo Hynynen
- Department of Medical Biophysics, University of Toronto, 101 College St, Room 15-701, Toronto, Canada.,Physical Sciences Platform, Sunnybrook Research Institute, Room C713, 2075 Bayview Ave, Toronto, Canada
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24
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Abstract
The understanding of brain function and the capacity to treat neurological and psychiatric disorders rest on the ability to intervene in neuronal activity in specific brain circuits. Current methods of neuromodulation incur a tradeoff between spatial focus and the level of invasiveness. Transcranial focused ultrasound (FUS) is emerging as a neuromodulation approach that combines noninvasiveness with focus that can be relatively sharp even in regions deep in the brain. This may enable studies of the causal role of specific brain regions in specific behaviors and behavioral disorders. In addition to causal brain mapping, the spatial focus of FUS opens new avenues for treatments of neurological and psychiatric conditions. This review introduces existing and emerging FUS applications in neuromodulation, discusses the mechanisms of FUS effects on cellular excitability, considers the effects of specific stimulation parameters, and lays out the directions for future work.
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Affiliation(s)
- Jan Kubanek
- Departments of Neurobiology and Radiology, Stanford University School of Medicine, Stanford, California
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25
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Maimbourg G, Houdouin A, Deffieux T, Tanter M, Aubry JF. 3D-printed adaptive acoustic lens as a disruptive technology for transcranial ultrasound therapy using single-element transducers. Phys Med Biol 2018; 63:025026. [PMID: 29219124 DOI: 10.1088/1361-6560/aaa037] [Citation(s) in RCA: 56] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
The development of multi-element arrays for better control of the shape of ultrasonic beams has opened the way for focusing through highly aberrating media, such as the human skull. As a result, the use of brain therapy with transcranial-focused ultrasound has rapidly grown. Although effective, such technology is expensive. We propose a disruptive, low-cost approach that consists of focusing a 1 MHz ultrasound beam through a human skull with a single-element transducer coupled with a tailored silicone acoustic lens cast in a 3D-printed mold and designed using computed tomography-based numerical acoustic simulation. We demonstrate on N = 3 human skulls that adding lens-based aberration correction to a single-element transducer increases the deposited energy on the target 10 fold.
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Affiliation(s)
- Guillaume Maimbourg
- INSERM U979, Institut Langevin, Paris, France. ESPCI Paris, Institut Langevin, PSL Research University, Paris, France. CNRS UMR 7587, Institut Langevin, Paris, France. Université Paris Diderot, Paris, France
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26
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Cohen-Inbar O, Snell J, Xu Z, Sheehan J. What Holds Focused Ultrasound Back? World Neurosurg 2016; 91:661-5. [DOI: 10.1016/j.wneu.2016.04.007] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2016] [Accepted: 04/02/2016] [Indexed: 12/21/2022]
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27
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Abstract
Ultrasonic waves can be non-invasively steered and focused into mm-scale regions across the human body and brain, and their application in generating controlled artificial modulation of neuronal activity could therefore potentially have profound implications for neural science and engineering. Ultrasonic neuro-modulation phenomena were experimentally observed and studied for nearly a century, with recent discoveries on direct neural excitation and suppression sparking a new wave of investigations in models ranging from rodents to humans. In this paper we review the physics, engineering and scientific aspects of ultrasonic fields, their control in both space and time, and their effect on neuronal activity, including a survey of both the field's foundational history and of recent findings. We describe key constraints encountered in this field, as well as key engineering systems developed to surmount them. In closing, the state of the art is discussed, with an emphasis on emerging research and clinical directions.
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Affiliation(s)
- Omer Naor
- Department of Biomedical Engineering, The Technion-Israel Institute of Technology Haifa 32000, Israel. The Edmond and Lily Safra Center for Brain Sciences (ELSC), The Hebrew University of Jerusalem, Jerusalem 91220, Israel
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28
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Weintraub D, Elias WJ. The emerging role of transcranial magnetic resonance imaging-guided focused ultrasound in functional neurosurgery. Mov Disord 2016; 32:20-27. [DOI: 10.1002/mds.26599] [Citation(s) in RCA: 39] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2016] [Accepted: 02/04/2016] [Indexed: 01/21/2023] Open
Affiliation(s)
- David Weintraub
- Department of Neurosurgery; University of Virginia; Charlottesville Virginia USA
| | - W. Jeffrey Elias
- Department of Neurosurgery; University of Virginia; Charlottesville Virginia USA
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29
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Farrer AI, Odéen H, de Bever J, Coats B, Parker DL, Payne A, Christensen DA. Characterization and evaluation of tissue-mimicking gelatin phantoms for use with MRgFUS. J Ther Ultrasound 2015; 3:9. [PMID: 26146557 PMCID: PMC4490606 DOI: 10.1186/s40349-015-0030-y] [Citation(s) in RCA: 71] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2015] [Accepted: 05/29/2015] [Indexed: 01/12/2023] Open
Abstract
Background A tissue-mimicking phantom that accurately represents human-tissue properties is important for safety testing and for validating new imaging techniques. To achieve a variety of desired human-tissue properties, we have fabricated and tested several variations of gelatin phantoms. These phantoms are simple to manufacture and have properties in the same order of magnitude as those of soft tissues. This is important for quality-assurance verification as well as validation of magnetic resonance-guided focused ultrasound (MRgFUS) treatment techniques. Methods The phantoms presented in this work were constructed from gelatin powders with three different bloom values (125, 175, and 250), each one allowing for a different mechanical stiffness of the phantom. Evaporated milk was used to replace half of the water in the recipe for the gelatin phantoms in order to achieve attenuation and speed of sound values in soft tissue ranges. These acoustic properties, along with MR (T1 and T2*), mechanical (density and Young’s modulus), and thermal properties (thermal diffusivity and specific heat capacity), were obtained through independent measurements for all three bloom types to characterize the gelatin phantoms. Thermal repeatability of the phantoms was also assessed using MRgFUS and MR thermometry. Results All the measured values fell within the literature-reported ranges of soft tissues. In heating tests using low-power (6.6 W) sonications, interleaved with high-power (up to 22.0 W) sonications, each of the three different bloom phantoms demonstrated repeatable temperature increases (10.4 ± 0.3 °C for 125-bloom, 10.2 ± 0.3 °C for 175-bloom, and 10.8 ± 0.2 °C for 250-bloom for all 6.6-W sonications) for heating durations of 18.1 s. Conclusion These evaporated milk-modified gelatin phantoms should serve as reliable, general soft tissue-mimicking MRgFUS phantoms.
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Affiliation(s)
- Alexis I Farrer
- Department of Bioengineering, University of Utah, Salt Lake City, UT USA ; Utah Center for Advanced Imaging Research, Department of Radiology, University of Utah, Salt Lake City, UT USA
| | - Henrik Odéen
- Utah Center for Advanced Imaging Research, Department of Radiology, University of Utah, Salt Lake City, UT USA ; Department of Physics and Astronomy, University of Utah, Salt Lake City, UT USA
| | - Joshua de Bever
- Utah Center for Advanced Imaging Research, Department of Radiology, University of Utah, Salt Lake City, UT USA ; School of Computing, University of Utah, Salt Lake City, UT USA
| | - Brittany Coats
- Department of Mechanical Engineering, University of Utah, Salt Lake City, UT USA
| | - Dennis L Parker
- Utah Center for Advanced Imaging Research, Department of Radiology, University of Utah, Salt Lake City, UT USA
| | - Allison Payne
- Utah Center for Advanced Imaging Research, Department of Radiology, University of Utah, Salt Lake City, UT USA
| | - Douglas A Christensen
- Department of Bioengineering, University of Utah, Salt Lake City, UT USA ; Department of Electrical and Computer Engineering, University of Utah, Salt Lake City, UT USA
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Xu Z, Carlson C, Snell J, Eames M, Hananel A, Lopes MB, Raghavan P, Lee CC, Yen CP, Schlesinger D, Kassell NF, Aubry JF, Sheehan J. Intracranial inertial cavitation threshold and thermal ablation lesion creation using MRI-guided 220-kHz focused ultrasound surgery: preclinical investigation. J Neurosurg 2015; 122:152-61. [PMID: 25380106 DOI: 10.3171/2014.9.jns14541] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
OBJECT In biological tissues, it is known that the creation of gas bubbles (cavitation) during ultrasound exposure is more likely to occur at lower rather than higher frequencies. Upon collapsing, such bubbles can induce hemorrhage. Thus, acoustic inertial cavitation secondary to a 220-kHz MRI-guided focused ultrasound (MRgFUS) surgery is a serious safety issue, and animal studies are mandatory for laying the groundwork for the use of low-frequency systems in future clinical trials. The authors investigate here the in vivo potential thresholds of MRgFUS-induced inertial cavitation and MRgFUS-induced thermal coagulation using MRI, acoustic spectroscopy, and histology. METHODS Ten female piglets that had undergone a craniectomy were sonicated using a 220-kHz transcranial MRgFUS system over an acoustic energy range of 5600-14,000 J. For each piglet, a long-duration sonication (40-second duration) was performed on the right thalamus, and a short sonication (20-second duration) was performed on the left thalamus. An acoustic power range of 140-300 W was used for long-duration sonications and 300-700 W for short-duration sonications. Signals collected by 2 passive cavitation detectors were stored in memory during each sonication, and any subsequent cavitation activity was integrated within the bandwidth of the detectors. Real-time 2D MR thermometry was performed during the sonications. T1-weighted, T2-weighted, gradient-recalled echo, and diffusion-weighted imaging MRI was performed after treatment to assess the lesions. The piglets were killed immediately after the last series of posttreatment MR images were obtained. Their brains were harvested, and histological examinations were then performed to further evaluate the lesions. RESULTS Two types of lesions were induced: thermal ablation lesions, as evidenced by an acute ischemic infarction on MRI and histology, and hemorrhagic lesions, associated with inertial cavitation. Passive cavitation signals exhibited 3 main patterns identified as follows: no cavitation, stable cavitation, and inertial cavitation. Low-power and longer sonications induced only thermal lesions, with a peak temperature threshold for lesioning of 53°C. Hemorrhagic lesions occurred only with high-power and shorter sonications. The sizes of the hemorrhages measured on macroscopic histological examinations correlated with the intensity of the cavitation activity (R2 = 0.74). The acoustic cavitation activity detected by the passive cavitation detectors exhibited a threshold of 0.09 V·Hz for the occurrence of hemorrhages. CONCLUSIONS This work demonstrates that 220-kHz ultrasound is capable of inducing a thermal lesion in the brain of living swines without hemorrhage. Although the same acoustic energy can induce either a hemorrhage or a thermal lesion, it seems that low-power, long-duration sonication is less likely to cause hemorrhage and may be safer. Although further study is needed to decrease the likelihood of ischemic infarction associated with the 220-kHz ultrasound, the threshold established in this work may allow for the detection and prevention of deleterious cavitations.
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