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Mohamed AA, Faragalla S, Khan A, Flynn G, Rainone G, Johansen PM, Lucke-Wold B. Neurosurgical and pharmacological management of dystonia. World J Psychiatry 2024; 14:624-634. [PMID: 38808085 PMCID: PMC11129150 DOI: 10.5498/wjp.v14.i5.624] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/04/2024] [Revised: 04/20/2024] [Accepted: 04/26/2024] [Indexed: 05/16/2024] Open
Abstract
Dystonia characterizes a group of neurological movement disorders characterized by abnormal muscle movements, often with repetitive or sustained contraction resulting in abnormal posturing. Different types of dystonia present based on the affected body regions and play a prominent role in determining the potential efficacy of a given intervention. For most patients afflicted with these disorders, an exact cause is rarely identified, so treatment mainly focuses on symptomatic alleviation. Pharmacological agents, such as oral anticholinergic administration and botulinum toxin injection, play a major role in the initial treatment of patients. In more severe and/or refractory cases, focal areas for neurosurgical intervention are identified and targeted to improve quality of life. Deep brain stimulation (DBS) targets these anatomical locations to minimize dystonia symptoms. Surgical ablation procedures and peripheral denervation surgeries also offer potential treatment to patients who do not respond to DBS. These management options grant providers and patients the ability to weigh the benefits and risks for each individual patient profile. This review article explores these pharmacological and neurosurgical management modalities for dystonia, providing a comprehensive assessment of each of their benefits and shortcomings.
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Affiliation(s)
- Ali Ahmed Mohamed
- Charles E Schmidt College of Medicine, Florida Atlantic University, Boca Raton, FL 33431, United States
| | - Steven Faragalla
- Charles E Schmidt College of Medicine, Florida Atlantic University, Boca Raton, FL 33431, United States
| | - Asad Khan
- Charles E Schmidt College of Medicine, Florida Atlantic University, Boca Raton, FL 33431, United States
| | - Garrett Flynn
- Charles E Schmidt College of Medicine, Florida Atlantic University, Boca Raton, FL 33431, United States
| | - Gersham Rainone
- Department of Neurosurgery and Brain Repair, University of South Florida, Tampa, FL 33606, United States
| | - Phillip Mitchell Johansen
- Department of Neurosurgery and Brain Repair, University of South Florida, Tampa, FL 33606, United States
| | - Brandon Lucke-Wold
- Department of Neurosurgery, University of Florida, Gainesville, FL 32611, United States
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2
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Perolina E, Meissner S, Raos B, Harland B, Thakur S, Svirskis D. Translating ultrasound-mediated drug delivery technologies for CNS applications. Adv Drug Deliv Rev 2024; 208:115274. [PMID: 38452815 DOI: 10.1016/j.addr.2024.115274] [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: 09/28/2023] [Revised: 02/18/2024] [Accepted: 03/01/2024] [Indexed: 03/09/2024]
Abstract
Ultrasound enhances drug delivery into the central nervous system (CNS) by opening barriers between the blood and CNS and by triggering release of drugs from carriers. A key challenge in translating setups from in vitro to in vivo settings is achieving equivalent acoustic energy delivery. Multiple devices have now been demonstrated to focus ultrasound to the brain, with concepts emerging to also target the spinal cord. Clinical trials to date have used ultrasound to facilitate the opening of the blood-brain barrier. While most have focused on feasibility and safety considerations, therapeutic benefits are beginning to emerge. To advance translation of these technologies for CNS applications, researchers should standardise exposure protocol and fine-tune ultrasound parameters. Computational modelling should be increasingly used as a core component to develop both in vitro and in vivo setups for delivering accurate and reproducible ultrasound to the CNS. This field holds promise for transformative advancements in the management and pharmacological treatment of complex and challenging CNS disorders.
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Affiliation(s)
- Ederlyn Perolina
- School of Pharmacy, Faculty of Medical and Health Sciences, University of Auckland, 85 Park Road, Auckland 1023, New Zealand
| | - Svenja Meissner
- School of Pharmacy, Faculty of Medical and Health Sciences, University of Auckland, 85 Park Road, Auckland 1023, New Zealand
| | - Brad Raos
- School of Pharmacy, Faculty of Medical and Health Sciences, University of Auckland, 85 Park Road, Auckland 1023, New Zealand
| | - Bruce Harland
- School of Pharmacy, Faculty of Medical and Health Sciences, University of Auckland, 85 Park Road, Auckland 1023, New Zealand
| | - Sachin Thakur
- School of Pharmacy, Faculty of Medical and Health Sciences, University of Auckland, 85 Park Road, Auckland 1023, New Zealand
| | - Darren Svirskis
- School of Pharmacy, Faculty of Medical and Health Sciences, University of Auckland, 85 Park Road, Auckland 1023, New Zealand.
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3
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Rosnitskiy PB, Khokhlova TD, Schade GR, Sapozhnikov OA, Khokhlova VA. Treatment Planning and Aberration Correction Algorithm for HIFU Ablation of Renal Tumors. IEEE TRANSACTIONS ON ULTRASONICS, FERROELECTRICS, AND FREQUENCY CONTROL 2024; 71:341-353. [PMID: 38231825 PMCID: PMC11003458 DOI: 10.1109/tuffc.2024.3355390] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/19/2024]
Abstract
High-intensity focused ultrasound (HIFU) applications for thermal or mechanical ablation of renal tumors often encounter challenges due to significant beam aberration and refraction caused by oblique beam incidence, inhomogeneous tissue layers, and presence of gas and bones within the beam. These losses can be significantly mitigated through sonication geometry planning, patient positioning, and aberration correction using multielement phased arrays. Here, a sonication planning algorithm is introduced, which uses the simulations to select the optimal transducer position and evaluate the effect of aberrations and acoustic field quality at the target region after aberration correction. Optimization of transducer positioning is implemented using a graphical user interface (GUI) to visualize a segmented 3-D computed tomography (CT)-based acoustic model of the body and to select sonication geometry through a combination of manual and automated approaches. An HIFU array (1.5 MHz, 256 elements) and three renal cell carcinoma (RCC) cases with different tumor locations and patient body habitus were considered. After array positioning, the correction of aberrations was performed using a combination of backpropagation from the focus with an ordinary least squares (OLS) optimization of phases at the array elements. The forward propagation was simulated using a combination of the Rayleigh integral and k-space pseudospectral method (k-Wave toolbox). After correction, simulated HIFU fields showed tight focusing and up to threefold higher maximum pressure within the target region. The addition of OLS optimization to the aberration correction method yielded up to 30% higher maximum pressure compared to the conventional backpropagation and up to 250% higher maximum pressure compared to the ray-tracing method, particularly in strongly distorted cases.
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Edsall C, Fergusson A, Davis RM, Meyer CH, Allen SP, Vlaisavljevich E. Probability of Cavitation in a Custom Iron-Based Coupling Medium for Transcranial Magnetic Resonance-Guided Focused Ultrasound Procedures. ULTRASOUND IN MEDICINE & BIOLOGY 2023; 49:2519-2526. [PMID: 37730478 PMCID: PMC10591864 DOI: 10.1016/j.ultrasmedbio.2023.08.015] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/30/2023] [Revised: 06/13/2023] [Accepted: 08/16/2023] [Indexed: 09/22/2023]
Abstract
OBJECTIVE A coupling bath of circulating, chilled, degassed water is essential to safe and precise acoustic transmittance during transcranial magnetic resonance-guided focused ultrasound (tMRgFUS) procedures, but the circulating water impairs the critical real-time magnetic resonance imaging (MRI). An iron-based coupling medium (IBCM) using iron oxide nanoparticles previously developed by our group increased the relaxivity of the coupling bath such that it appears to be invisible on MRI compared with degassed water. However, the nanoparticles also reduced the pressure threshold for cavitation. To address this concern for prefocal cavitation, our group recently developed an IBCM of electrosterically stabilized and aggregation-resistant poly(methacrylic acid)-coated iron oxide nanoparticles (PMAA-FeOX) with a similar capability to reduce the MR signal of degassed water. This study examines the effect of the PMAA-FeOX IBCM on the cavitation threshold. METHODS Increasing concentrations of PMAA-FeOX nanoparticles in degassed, deionized water were placed at the focus of two different transducers to assess low and high duty-cycle pulsing parameters which are representative of two modes of focused ultrasound being investigated for tMRgFUS. Passive cavitation detection and high-speed optical imaging were used to measure cavitation threshold pressures. RESULTS The mean cavitation threshold was determined in both cases to be indistinguishable from the degassed water control, between 6-8 MPa for high duty-cycle pulsing (CW) and between 25.5-26.5 MPa for very low duty-cycle pulsing. CONCLUSION The findings of this study indicate that an IBCM of PMAA-FeOX nanoparticles is a possible solution to reducing MRI interference from the coupling bath without increasing the risk of prefocal cavitation.
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Affiliation(s)
- Connor Edsall
- Department of Biomedical Engineering and Mechanics, Virginia Polytechnic Institute and State University, Blacksburg, VA, USA
| | - Austin Fergusson
- Translational Biology, Medicine, and Health Graduate Program, Virginia Polytechnic Institute and State University, Blacksburg, VA, USA
| | - Richey M Davis
- Department of Chemical Engineering, Virginia Polytechnic Institute and State University, Blacksburg, VA, USA
| | - Craig H Meyer
- Biomedical Engineering, University of Virginia, Charlottesville, VA, USA
| | - Steven P Allen
- Department of Electrical and Computer Engineering, Brigham Young University, Provo, UT, USA
| | - Eli Vlaisavljevich
- Department of Biomedical Engineering and Mechanics, Virginia Polytechnic Institute and State University, Blacksburg, VA, USA; ICTAS Center for Engineered Health, Virginia Polytechnic Institute and State University, Blacksburg, VA, USA.
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Yeats E, Hall TL. Aberration correction in abdominal histotripsy. Int J Hyperthermia 2023; 40:2266594. [PMID: 37813397 PMCID: PMC10637766 DOI: 10.1080/02656736.2023.2266594] [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: 08/02/2023] [Accepted: 09/28/2023] [Indexed: 10/11/2023] Open
Abstract
In transabdominal histotripsy, ultrasound pulses are focused on the body to noninvasively destroy soft tissues via cavitation. However, the ability to focus is limited by phase aberration, or decorrelation of the ultrasound pulses due to spatial variation in the speed of sound throughout heterogeneous tissue. Phase aberration shifts, broadens, and weakens the focus, thereby reducing the safety and efficacy of histotripsy therapy. This paper reviews and discusses aberration effects in histotripsy and in related therapeutic ultrasound techniques (e.g., high intensity focused ultrasound), with an emphasis on aberration by soft tissues. Methods for aberration correction are reviewed and can be classified into two groups: model-based methods, which use segmented images of the tissue as input to an acoustic propagation model to predict and compensate phase differences, and signal-based methods, which use a receive-capable therapy array to detect phase differences by sensing acoustic signals backpropagating from the focus. The relative advantages and disadvantages of both groups of methods are discussed. Importantly, model-based methods can correct focal shift, while signal-based methods can restore substantial focal pressure, suggesting that both methods should be combined in a 2-step approach. Aberration correction will be critical to improving histotripsy treatments and expanding the histotripsy treatment envelope to enable non-invasive, non-thermal histotripsy therapy for more patients.
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Affiliation(s)
- Ellen Yeats
- Department of Biomedical Engineering, University of Michigan, Ann Arbor, Michigan, United States
| | - Timothy L. Hall
- Department of Biomedical Engineering, University of Michigan, Ann Arbor, Michigan, United States
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Pellow C, Li S, Delgado S, Pike GB, Curiel L, Pichardo S. Biaxial ultrasound driving technique for small animal blood-brain barrier opening. Phys Med Biol 2023; 68:195006. [PMID: 37607563 DOI: 10.1088/1361-6560/acf2e3] [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: 06/09/2023] [Accepted: 08/22/2023] [Indexed: 08/24/2023]
Abstract
Biaxial driving can more efficiently convert electrical power to forward acoustic power in piezoelectric materials, and the interaction between the orthogonal electric fields can produce a combination of extensional and shear deformations as a function of the phase difference between them to allow dynamic steering of the beam with a single-element. In this study, we demonstrate for the first time the application of a single-element biaxially driven ring transducerin vivofor blood-brain barrier opening in mice, and compare it to that achieved with a conventional single-element highly focused (F# = 0.7) spherical transducer operating at a similar frequency. Transcranial focused ultrasound (0.45 MPa, 10 ms pulse length, 1 Hz repetition frequency, 30 s duration) was applied bilaterally to mice with a 40μl/kg bolus of DefinityTMmicrobubbles, employing either a single-element biaxial ring (1.482 MHz, 10 mm inner diameter, 13.75 mm outer diameter) or spherical (1.5 MHz, 35 mm diameter, F# = 0.7; RK50, FUS Instruments) transducer on each side. Follow-up MRI scans (T1 pre- and post- 0.2 mmol/kg Gd injection, T2) were acquired to assess blood-brain barrier opening volume and potential damage. Compared to blood-brain barrier opening achieved with a conventional single-element spherical focused transducer, the opening volume achieved with a single-element biaxial ring transducer was 35% smaller (p= 0.002) with a device of a ring diameter of 40% the aperture size. Axial refocusing was further demonstrated with the single-element biaxial ring transducer, yielding a 1.63 mm deeper, five-fold larger opening volume (p= 0.048) relative to its small-focus mode. The biaxial ring transducer achieved a more localized opening compared to the spherical focused transducer under the same parameters, and further enabled dynamic axial refocusing with a single-element transducer with a smaller fabrication footprint.
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Affiliation(s)
- Carly Pellow
- Department of Radiology, Cumming School of Medicine, University of Calgary, Alberta, Canada
- Hotchkiss Brain Institute, University of Calgary, Alberta, Canada
| | - Siyun Li
- Department of Radiology, Cumming School of Medicine, University of Calgary, Alberta, Canada
| | - Sagid Delgado
- Department of Radiology, Cumming School of Medicine, University of Calgary, Alberta, Canada
| | - G Bruce Pike
- Department of Radiology, Cumming School of Medicine, University of Calgary, Alberta, Canada
- Hotchkiss Brain Institute, University of Calgary, Alberta, Canada
- Department of Clinical Neurosciences, Cumming School of Medicine, University of Calgary, Alberta, Canada
| | - Laura Curiel
- Hotchkiss Brain Institute, University of Calgary, Alberta, Canada
- Department of Biomedical Engineering, Schulich School of Engineering, University of Calgary, Alberta, Canada
| | - Samuel Pichardo
- Department of Radiology, Cumming School of Medicine, University of Calgary, Alberta, Canada
- Hotchkiss Brain Institute, University of Calgary, Alberta, Canada
- Department of Clinical Neurosciences, Cumming School of Medicine, University of Calgary, Alberta, Canada
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Yoo SS, Kim E, Kowsari K, Van Reet J, Kim HC, Yoon K. Non-invasive enhancement of intracortical solute clearance using transcranial focused ultrasound. Sci Rep 2023; 13:12339. [PMID: 37524783 PMCID: PMC10390479 DOI: 10.1038/s41598-023-39640-2] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2023] [Accepted: 07/28/2023] [Indexed: 08/02/2023] Open
Abstract
Transport of interstitial fluid and solutes plays a critical role in clearing metabolic waste from the brain. Transcranial application of focused ultrasound (FUS) has been shown to promote localized cerebrospinal fluid solute uptake into the brain parenchyma; however, its effects on the transport and clearance of interstitial solutes remain unknown. We demonstrate that pulsed application of low-intensity FUS to the rat brain enhances the transport of intracortically injected fluorescent tracers (ovalbumin and high molecular-weight dextran), yielding greater parenchymal tracer volume distribution compared to the unsonicated control group (ovalbumin by 40.1% and dextran by 34.6%). Furthermore, FUS promoted the drainage of injected interstitial ovalbumin to both superficial and deep cervical lymph nodes (cLNs) ipsilateral to sonication, with 78.3% higher drainage observed in the superficial cLNs compared to the non-sonicated hemisphere. The application of FUS increased the level of solute transport visible from the dorsal brain surface, with ~ 43% greater area and ~ 19% higher fluorescence intensity than the unsonicated group, especially in the pial surface ipsilateral to sonication. The sonication did not elicit tissue-level neuronal excitation, measured by an electroencephalogram, nor did it alter the molecular weight of the tracers. These findings suggest that nonthermal transcranial FUS can enhance advective transport of interstitial solutes and their subsequent removal in a completely non-invasive fashion, offering its potential non-pharmacological utility in facilitating clearance of waste from the brain.
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Affiliation(s)
- Seung-Schik Yoo
- Department of Radiology, Brigham and Women's Hospital, Harvard Medical School, 75 Francis Street, MA, 02115, Boston, USA.
| | - Evgenii Kim
- Department of Radiology, Brigham and Women's Hospital, Harvard Medical School, 75 Francis Street, MA, 02115, Boston, USA
| | - Kavin Kowsari
- Department of Radiology, Brigham and Women's Hospital, Harvard Medical School, 75 Francis Street, MA, 02115, Boston, USA
| | - Jared Van Reet
- Department of Radiology, Brigham and Women's Hospital, Harvard Medical School, 75 Francis Street, MA, 02115, Boston, USA
| | - Hyun-Chul Kim
- Department of Radiology, Brigham and Women's Hospital, Harvard Medical School, 75 Francis Street, MA, 02115, Boston, USA
- Department of Artificial Intelligence, Kyungpook National University, Daegu, Republic of Korea
| | - Kyungho Yoon
- School of Computational Science and Engineering, Yonsei University, Seoul, Republic of Korea
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Antoniou A, Evripidou N, Damianou C. Focused ultrasound heating in brain tissue/skull phantoms with 1 MHz single-element transducer. J Ultrasound 2023:10.1007/s40477-023-00810-7. [PMID: 37517052 DOI: 10.1007/s40477-023-00810-7] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2023] [Accepted: 07/09/2023] [Indexed: 08/01/2023] Open
Abstract
PURPOSE The study aims to provide insights on the practicality of using single-element transducers for transcranial Focused Ultrasound (tFUS) thermal applications. METHODS FUS sonications were performed through skull phantoms embedding agar-based tissue mimicking gels using a 1 MHz single-element spherically focused transducer. The skull phantoms were 3D printed with Acrylonitrile Butadiene Styrene (ABS) and Resin thermoplastics having the exact skull bone geometry of a healthy volunteer. The temperature field distribution during and after heating was monitored in a 3 T Magnetic Resonance Imaging (MRI) scanner using MR thermometry. The effect of the skull's thickness on intracranial heating was investigated. RESULTS A single FUS sonication at focal acoustic intensities close to 1580 W/cm2 for 60 s in free field heated up the agar phantom to ablative temperatures reaching about 90 °C (baseline of 37 °C). The ABS skull strongly blocked the ultrasonic waves, resulting in zero temperature increase within the phantom. Considerable heating was achieved through the Resin skull, but it remained at hyperthermia levels. Conversely, tFUS through a 1 mm Resin skull showed enhanced ultrasonic penetration and heating, with the focal temperature reaching 70 °C. CONCLUSIONS The ABS skull demonstrated poorer performance in terms of tFUS compared to the Resin skull owing to its higher ultrasonic attenuation and porosity. The thin Resin phantom of 1 mm thickness provided an efficient acoustic window for delivering tFUS and heating up deep phantom areas. The results of such studies could be particularly useful for accelerating the establishment of a wider range of tFUS applications.
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Affiliation(s)
- Anastasia Antoniou
- Department of Electrical Engineering, Computer Engineering, and Informatics, Cyprus University of Technology, 30 Archbishop Kyprianou Street, 3036, Limassol, Cyprus
| | - Nikolas Evripidou
- Department of Electrical Engineering, Computer Engineering, and Informatics, Cyprus University of Technology, 30 Archbishop Kyprianou Street, 3036, Limassol, Cyprus
| | - Christakis Damianou
- Department of Electrical Engineering, Computer Engineering, and Informatics, Cyprus University of Technology, 30 Archbishop Kyprianou Street, 3036, Limassol, Cyprus.
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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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10
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Hughes A, Khan DS, Alkins R. Current and Emerging Systems for Focused Ultrasound-Mediated Blood-Brain Barrier Opening. ULTRASOUND IN MEDICINE & BIOLOGY 2023; 49:1479-1490. [PMID: 37100672 DOI: 10.1016/j.ultrasmedbio.2023.02.017] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/29/2022] [Revised: 02/09/2023] [Accepted: 02/23/2023] [Indexed: 05/17/2023]
Abstract
With an ever-growing list of neurological applications of focused ultrasound (FUS), there has been a consequent increase in the variety of systems for delivering ultrasound energy to the brain. Specifically, recent successful pilot clinical trials of blood-brain barrier (BBB) opening with FUS have generated substantial interest in the future applications of this relatively novel therapy, with divergent, purpose-built technologies emerging. With many of these technologies at various stages of pre-clinical and clinical investigation, this article seeks to provide an overview and analysis of the numerous medical devices in active use and under development for FUS-mediated BBB opening.
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Affiliation(s)
- Alec Hughes
- School of Medicine, Faculty of Health Sciences, Queen's University, Kingston, ON, Canada
| | - Dure S Khan
- Centre for Neuroscience Studies, Queen's University, Kingston, ON, Canada
| | - Ryan Alkins
- Centre for Neuroscience Studies, Queen's University, Kingston, ON, Canada; Division of Neurosurgery, Department of Surgery, Kingston Health Sciences Centre, Queen's University, Kingston, ON, Canada.
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11
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Dahmani L, Bai Y, Li M, Ren J, Shen L, Ma J, Li H, Wei W, Li P, Wang D, Du L, Cui W, Liu H, Wang M. Focused ultrasound thalamotomy for tremor treatment impacts the cerebello-thalamo-cortical network. NPJ Parkinsons Dis 2023; 9:90. [PMID: 37322044 DOI: 10.1038/s41531-023-00543-8] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2023] [Accepted: 06/05/2023] [Indexed: 06/17/2023] Open
Abstract
High-intensity Magnetic Resonance-guided Focused Ultrasound (MRgFUS) is a recent, non-invasive line of treatment for medication-resistant tremor. We used MRgFUS to produce small lesions in the thalamic ventral intermediate nucleus (VIM), an important node in the cerebello-thalamo-cortical tremor network, in 13 patients with tremor-dominant Parkinson's disease or essential tremor. Significant tremor alleviation in the target hand ensued (t(12) = 7.21, p < 0.001, two-tailed), which was strongly associated with the functional reorganization of the brain's hand region with the cerebellum (r = 0.91, p < 0.001, one-tailed). This reorganization potentially reflected a process of normalization, as there was a trend of increase in similarity between the hand cerebellar connectivity of the patients and that of a matched, healthy control group (n = 48) after treatment. Control regions in the ventral attention, dorsal attention, default, and frontoparietal networks, in comparison, exhibited no association with tremor alleviation and no normalization. More broadly, changes in functional connectivity were observed in regions belonging to the motor, limbic, visual, and dorsal attention networks, largely overlapping with regions connected to the lesion targets. Our results indicate that MRgFUS is a highly efficient treatment for tremor, and that lesioning the VIM may result in the reorganization of the cerebello-thalamo-cortical tremor network.
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Affiliation(s)
- Louisa Dahmani
- Department of Medical Imaging, Henan Provincial People's Hospital & People Hospital of Zhengzhou University, Zhengzhou, China
- Athinoula A. Martinos Center for Biomedical Imaging, Department of Radiology, Massachusetts General Hospital, Harvard Medical School, Charlestown, MA, 02129, USA
| | - Yan Bai
- Department of Medical Imaging, Henan Provincial People's Hospital & People Hospital of Zhengzhou University, Zhengzhou, China
| | - Meiling Li
- Athinoula A. Martinos Center for Biomedical Imaging, Department of Radiology, Massachusetts General Hospital, Harvard Medical School, Charlestown, MA, 02129, USA
| | - Jianxun Ren
- Athinoula A. Martinos Center for Biomedical Imaging, Department of Radiology, Massachusetts General Hospital, Harvard Medical School, Charlestown, MA, 02129, USA
| | - Lunhao Shen
- Athinoula A. Martinos Center for Biomedical Imaging, Department of Radiology, Massachusetts General Hospital, Harvard Medical School, Charlestown, MA, 02129, USA
| | - Jianjun Ma
- Department of Neurology, Henan Provincial People's Hospital & People Hospital of Zhengzhou University, Zhengzhou, China
| | - Haiyang Li
- Department of Neurosurgery, Henan Provincial People's Hospital & People Hospital of Zhengzhou University, Zhengzhou, China
| | - Wei Wei
- Department of Medical Imaging, Henan Provincial People's Hospital & People Hospital of Zhengzhou University, Zhengzhou, China
| | - Pengyu Li
- Department of Medical Imaging, Henan Provincial People's Hospital & People Hospital of Zhengzhou University, Zhengzhou, China
| | - Danhong Wang
- Athinoula A. Martinos Center for Biomedical Imaging, Department of Radiology, Massachusetts General Hospital, Harvard Medical School, Charlestown, MA, 02129, USA
| | - Lei Du
- Athinoula A. Martinos Center for Biomedical Imaging, Department of Radiology, Massachusetts General Hospital, Harvard Medical School, Charlestown, MA, 02129, USA
| | | | - Hesheng Liu
- Athinoula A. Martinos Center for Biomedical Imaging, Department of Radiology, Massachusetts General Hospital, Harvard Medical School, Charlestown, MA, 02129, USA.
- Changping Laboratory, Beijing, China.
- Biomedical Pioneering Innovation Center, Peking University, Beijing, China.
| | - Meiyun Wang
- Department of Medical Imaging, Henan Provincial People's Hospital & People Hospital of Zhengzhou University, Zhengzhou, China.
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12
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Li KP, Wu JJ, Zhou ZL, Xu DS, Zheng MX, Hua XY, Xu JG. Noninvasive Brain Stimulation for Neurorehabilitation in Post-Stroke Patients. Brain Sci 2023; 13:brainsci13030451. [PMID: 36979261 PMCID: PMC10046557 DOI: 10.3390/brainsci13030451] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2022] [Revised: 02/26/2023] [Accepted: 02/27/2023] [Indexed: 03/09/2023] Open
Abstract
Characterized by high morbidity, mortality, and disability, stroke usually causes symptoms of cerebral hypoxia due to a sudden blockage or rupture of brain vessels, and it seriously threatens human life and health. Rehabilitation is the essential treatment for post-stroke patients suffering from functional impairments, through which hemiparesis, aphasia, dysphagia, unilateral neglect, depression, and cognitive dysfunction can be restored to various degrees. Noninvasive brain stimulation (NIBS) is a popular neuromodulatory technology of rehabilitation focusing on the local cerebral cortex, which can improve clinical functions by regulating the excitability of corresponding neurons. Increasing evidence has been obtained from the clinical application of NIBS, especially repetitive transcranial magnetic stimulation (rTMS) and transcranial direct current stimulation (tDCS). However, without a standardized protocol, existing studies on NIBS show a wide variation in terms of stimulation site, frequency, intensity, dosage, and other parameters. Its application for neurorehabilitation in post-stroke patients is still limited. With advances in neuronavigation technologies, functional near-infrared spectroscopy, and functional MRI, specific brain regions can be precisely located for stimulation. On the basis of our further understanding on neural circuits, neuromodulation in post-stroke rehabilitation has also evolved from single-target stimulation to co-stimulation of two or more targets, even circuits and the network. The present study aims to review the findings of current research, discuss future directions of NIBS application, and finally promote the use of NIBS in post-stroke rehabilitation.
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Affiliation(s)
- Kun-Peng Li
- School of Rehabilitation Science, Shanghai University of Traditional Chinese Medicine, Shanghai 201203, China
| | - Jia-Jia Wu
- Center of Rehabilitation Medicine, Yueyang Hospital of Integrated Traditional Chinese and Western Medicine, Shanghai University of Traditional Chinese Medicine, Shanghai 200437, China
| | - Zong-Lei Zhou
- Department of Epidemiology, School of Public Health, Fudan University, Shanghai 200032, China
| | - Dong-Sheng Xu
- School of Rehabilitation Science, Shanghai University of Traditional Chinese Medicine, Shanghai 201203, China
| | - Mou-Xiong Zheng
- Department of Traumatology and Orthopedics, Yueyang Hospital of Integrated Traditional Chinese and Western Medicine, Shanghai University of Traditional Chinese Medicine, Shanghai 200437, China
- Correspondence: (M.-X.Z.); (X.-Y.H.); (J.-G.X.)
| | - Xu-Yun Hua
- Department of Traumatology and Orthopedics, Yueyang Hospital of Integrated Traditional Chinese and Western Medicine, Shanghai University of Traditional Chinese Medicine, Shanghai 200437, China
- Correspondence: (M.-X.Z.); (X.-Y.H.); (J.-G.X.)
| | - Jian-Guang Xu
- School of Rehabilitation Science, Shanghai University of Traditional Chinese Medicine, Shanghai 201203, China
- Engineering Research Center of Traditional Chinese Medicine Intelligent Rehabilitation, Ministry of Education, Shanghai 201203, China
- Correspondence: (M.-X.Z.); (X.-Y.H.); (J.-G.X.)
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13
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Pan X, Zeng L, Li Y, Zhu X, Jin Y. Experimental demonstration of Fresnel zone plate lens for robust subwavelength focusing at mega hertz. ULTRASONICS 2023; 128:106876. [PMID: 36272298 DOI: 10.1016/j.ultras.2022.106876] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/30/2022] [Revised: 09/21/2022] [Accepted: 10/11/2022] [Indexed: 05/23/2023]
Abstract
Acoustic focusing with high energy intensity, broadband and few side lobes properties are highly demanded in many fields and can be achieved with Fresnel zone plate (FZP) lens as an artificial structure. However, FZP focusing lenses for high frequency range such as around 5 MHz with precise focusing effect has not been demonstrated and the dependence of the size, especially the full width at half maximum (FWHM), of the focal spot has not been well explored. In this work, we numerically and experimentally study the FZP lenses for robust and subwavelength underwater sound focusing effect around 5 MHz. Stable subwavelength FWHM of the focusing spot over a broad frequency range is achieved. It is found that the FWHM has a quasi-linear relationship with the ratio between the focal length and the diameter of the lens. A quasi-linear relationship between the focal length and working frequency is also validated theoretically, numerically and experimentally. Our study proposes broadband and robust FZP lenses paving the way for high quality acoustic focusing at Mega Hertz frequency range for the development of imaging, non-destructive evaluation, and so on.
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Affiliation(s)
- Xiao Pan
- School of Aerospace Engineering and Applied Mechanics, Tongji University, 200092 Shanghai, China
| | - Longsheng Zeng
- School of Physics and Innovation Institute, Huazhong University of Science and Technology, 430074 Wuhan, China
| | - Yong Li
- Institute of Acoustics, School of Physics Science and Engineering, Tongji University, 200092 Shanghai, China.
| | - Xuefeng Zhu
- School of Physics and Innovation Institute, Huazhong University of Science and Technology, 430074 Wuhan, China.
| | - Yabin Jin
- School of Aerospace Engineering and Applied Mechanics, Tongji University, 200092 Shanghai, China.
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14
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Jo S, Sun IC, Ahn CH, Lee S, Kim K. Recent Trend of Ultrasound-Mediated Nanoparticle Delivery for Brain Imaging and Treatment. ACS APPLIED MATERIALS & INTERFACES 2023; 15:120-137. [PMID: 35184560 DOI: 10.1021/acsami.1c22803] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/14/2023]
Abstract
In view of the fact that the blood-brain barrier (BBB) prevents the transport of imaging probes and therapeutic agents to the brain and thus hinders the diagnosis and treatment of brain-related disorders, methods of circumventing this problem (e.g., ultrasound-mediated nanoparticle delivery) have drawn much attention. Among the related techniques, focused ultrasound (FUS) is a favorite means of enhancing drug delivery via transient BBB opening. Photoacoustic brain imaging relies on the conversion of light into heat and the detection of ultrasound signals from contrast agents, offering the benefits of high resolution and large penetration depth. The extensive versatility and adjustable physicochemical properties of nanoparticles make them promising therapeutic agents and imaging probes, allowing for successful brain imaging and treatment through the combined action of ultrasound and nanoparticulate agents. FUS-induced BBB opening enables nanoparticle-based drug delivery systems to efficiently access the brain. Moreover, photoacoustic brain imaging using nanoparticle-based contrast agents effectively visualizes brain morphologies or diseases. Herein, we review the progress in the simultaneous use of nanoparticles and ultrasound in brain research, revealing the potential of ultrasound-mediated nanoparticle delivery for the effective diagnosis and treatment of brain disorders.
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Affiliation(s)
- SeongHoon Jo
- Center for Theragnosis, Biomedical Research Institute, Korea Institute of Science and Technology, 5, Hwarang-ro, Seongbuk-gu, Seoul 02792, Republic of Korea
- Research Institute of Advanced Materials (RIAM), Department of Materials Science and Engineering, Seoul National University, 1 Gwanak-ro, Gwanak-gu, Seoul08826, Republic of Korea
| | - In-Cheol Sun
- Center for Theragnosis, Biomedical Research Institute, Korea Institute of Science and Technology, 5, Hwarang-ro, Seongbuk-gu, Seoul 02792, Republic of Korea
| | - Cheol-Hee Ahn
- Research Institute of Advanced Materials (RIAM), Department of Materials Science and Engineering, Seoul National University, 1 Gwanak-ro, Gwanak-gu, Seoul08826, Republic of Korea
| | - Sangmin Lee
- Department of Pharmacy, College of Pharmacy, Kyung Hee University, 26 Kyungheedae-ro, Dongdaemun-gu, Seoul02447, Korea
| | - Kwangmeyung Kim
- Center for Theragnosis, Biomedical Research Institute, Korea Institute of Science and Technology, 5, Hwarang-ro, Seongbuk-gu, Seoul 02792, Republic of Korea
- KU-KIST Graduate School of Converging Science and Technology, Korea University, 145 Anam-ro, Seongbuk-gu, Seoul 02841, Republic of Korea
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15
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Bao SC, Li F, Xiao Y, Niu L, Zheng H. Peripheral focused ultrasound stimulation and its applications: From therapeutics to human-computer interaction. Front Neurosci 2023; 17:1115946. [PMID: 37123351 PMCID: PMC10140332 DOI: 10.3389/fnins.2023.1115946] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2022] [Accepted: 03/24/2023] [Indexed: 05/02/2023] Open
Abstract
Peripheral focused ultrasound stimulation (pFUS) has gained increasing attention in the past few decades, because it can be delivered to peripheral nerves, neural endings, or sub-organs. With different stimulation parameters, ultrasound stimulation could induce different modulation effects. Depending on the transmission medium, pFUS can be classified as body-coupled US stimulation, commonly used for therapeutics or neuromodulation, or as an air-coupled contactless US haptic system, which provides sensory inputs and allows distinct human-computer interaction paradigms. Despite growing interest in pFUS, the underlying working mechanisms remain only partially understood, and many applications are still in their infancy. This review focused on existing applications, working mechanisms, the latest progress, and future directions of pFUS. In terms of therapeutics, large-sample randomized clinical trials in humans are needed to translate these state of art techniques into treatments for specific diseases. The airborne US for human-computer interaction is still in its preliminary stage, but further efforts in task-oriented US applications might provide a promising interaction tool soon.
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Affiliation(s)
- Shi-Chun Bao
- National Innovation Center for Advanced Medical Devices, Shenzhen, China
- Paul C. Lauterbur Research Center for Biomedical Imaging, Shenzhen Institute of Advanced Technology, Chinese Academy of Sciences, Shenzhen, China
| | - Fei Li
- Paul C. Lauterbur Research Center for Biomedical Imaging, Shenzhen Institute of Advanced Technology, Chinese Academy of Sciences, Shenzhen, China
| | - Yang Xiao
- National Innovation Center for Advanced Medical Devices, Shenzhen, China
- Paul C. Lauterbur Research Center for Biomedical Imaging, Shenzhen Institute of Advanced Technology, Chinese Academy of Sciences, Shenzhen, China
| | - Lili Niu
- Paul C. Lauterbur Research Center for Biomedical Imaging, Shenzhen Institute of Advanced Technology, Chinese Academy of Sciences, Shenzhen, China
| | - Hairong Zheng
- Paul C. Lauterbur Research Center for Biomedical Imaging, Shenzhen Institute of Advanced Technology, Chinese Academy of Sciences, Shenzhen, China
- *Correspondence: Hairong Zheng,
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16
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Filippou A, Damianou C. Experimental evaluation of high intensity focused ultrasound for fat reduction of ex vivo porcine adipose tissue. J Ultrasound 2022; 25:815-825. [PMID: 35106735 PMCID: PMC9705658 DOI: 10.1007/s40477-022-00663-6] [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: 11/30/2021] [Accepted: 01/12/2022] [Indexed: 10/19/2022] Open
Abstract
PURPOSE The present study was stimulated by the continuous growth of commercially available high intensity focused ultrasound (HIFU) systems for fat reduction. Herein, HIFU was utilised for fat ablation using a single-element ultrasonic transducer operating in thermal mode. METHODS The custom-made concave transducer that operates at 1.1 MHz was assessed on excised porcine adipose tissue for its ability to reduce fat. Ultrasonic sonications were executed on the adipose tissue utilising acoustical power between 14 and 75 W and sonication time in the range of 1-10 min. The mass of the adipose tissue sample was weighed afore and after ultrasonic sonications and the effect of the sonication on the mass change was recorded. RESULTS Mass change was linearly dependent with either increasing acoustical power or sonication time and was in the range of 0.46-1.9 g. High acoustical power of 62.5 W for a sonication time of 1 min and a power of 75 W for a sonication time of 5 min, respectively resulted in the formation of a lesion or possible cavitation on the piece of excised adipose tissue. CONCLUSION The study demonstrated the efficacy of the proposed transducer in achieving a reduction of excised fat tissue. The present findings indicate the potential use of the transducer in a HIFU system indicated for the reduction of subcutaneous adipose tissue where increased values of acoustical power can result in increased amounts of fat reduction.
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Affiliation(s)
- Antria Filippou
- Department of Electrical Engineering, Computer Engineering and Informatics, Cyprus University of Technology, 30 Archbishop Kyprianou Street, 3036, Limassol, Cyprus
| | - Christakis Damianou
- Department of Electrical Engineering, Computer Engineering and Informatics, Cyprus University of Technology, 30 Archbishop Kyprianou Street, 3036, Limassol, Cyprus.
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17
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Barzegar-Fallah A, Gandhi K, Rizwan SB, Slatter TL, Reynolds JNJ. Harnessing Ultrasound for Targeting Drug Delivery to the Brain and Breaching the Blood–Brain Tumour Barrier. Pharmaceutics 2022; 14:pharmaceutics14102231. [PMID: 36297666 PMCID: PMC9607160 DOI: 10.3390/pharmaceutics14102231] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2022] [Revised: 10/11/2022] [Accepted: 10/17/2022] [Indexed: 11/16/2022] Open
Abstract
Despite significant advances in developing drugs to treat brain tumours, achieving therapeutic concentrations of the drug at the tumour site remains a major challenge due to the presence of the blood–brain barrier (BBB). Several strategies have evolved to enhance brain delivery of chemotherapeutic agents to treat tumours; however, most approaches have several limitations which hinder their clinical utility. Promising studies indicate that ultrasound can penetrate the skull to target specific brain regions and transiently open the BBB, safely and reversibly, with a high degree of spatial and temporal specificity. In this review, we initially describe the basics of therapeutic ultrasound, then detail ultrasound-based drug delivery strategies to the brain and the mechanisms by which ultrasound can improve brain tumour therapy. We review pre-clinical and clinical findings from ultrasound-mediated BBB opening and drug delivery studies and outline current therapeutic ultrasound devices and technologies designed for this purpose.
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Affiliation(s)
- Anita Barzegar-Fallah
- Department of Anatomy, School of Biomedical Sciences, University of Otago, Dunedin 9016, New Zealand
- Brain Health Research Centre, University of Otago, Dunedin 9016, New Zealand
| | - Kushan Gandhi
- Department of Anatomy, School of Biomedical Sciences, University of Otago, Dunedin 9016, New Zealand
- Brain Health Research Centre, University of Otago, Dunedin 9016, New Zealand
| | - Shakila B. Rizwan
- Brain Health Research Centre, University of Otago, Dunedin 9016, New Zealand
- School of Pharmacy, University of Otago, Dunedin 9016, New Zealand
| | - Tania L. Slatter
- Department of Pathology, Dunedin School of Medicine, University of Otago, Dunedin 9016, New Zealand
| | - John N. J. Reynolds
- Department of Anatomy, School of Biomedical Sciences, University of Otago, Dunedin 9016, New Zealand
- Brain Health Research Centre, University of Otago, Dunedin 9016, New Zealand
- Correspondence: ; Tel.: +64-3-479-5781; Fax: +64-3-479-7254
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18
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Choi W, Key J, Youn I, Lee H, Han S. Cavitation-assisted sonothrombolysis by asymmetrical nanostars for accelerated thrombolysis. J Control Release 2022; 350:870-885. [PMID: 36096365 DOI: 10.1016/j.jconrel.2022.09.008] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2022] [Revised: 08/30/2022] [Accepted: 09/05/2022] [Indexed: 11/18/2022]
Abstract
Sonothrombolysis with recombinant tissue plasminogen activator (rtPA) and microbubbles has been widely studied to enhance thrombolytic potential. Here, we report different sonothrombolysis strategy in nanoparticles using microbubbles cavitation. We found that different particles in shape exhibited different reactivity toward the cavitation, leading to a distinct sonothrombolytic potential. Two different gold nanoparticles in shape were functionalized with the rtPA: rtPA-functionalized gold nanospheres (NPt) and gold nanostars (NSt). NPt could not accelerate the thrombolytic potential with a sole acoustic stimulus. Importantly, NSt enhanced the potential with acoustic stimulus and microbubble-mediated cavitation, while NPt were not reactive to cavitation. Coadministration of NSt and microbubbles resulted in a dramatic reduction of the infarcts in a photothrombotic model and recovery in the cerebral blood flow. Given the synergistic effect and in vivo feasibility of this strategy, cavitation-assisted sonothrombolysis by asymmetrical NSt might be useful for treating acute ischemic stroke.
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Affiliation(s)
- Wonseok Choi
- Biomedical Research Division, Korea Institute of Science and Technology (KIST), Seoul 02792, Seongbuk-gu, Republic of Korea; Department of Biomedical Engineering, Yonsei University, Wonju 26493, Gangwon-do, Republic of Korea
| | - Jaehong Key
- Department of Biomedical Engineering, Yonsei University, Wonju 26493, Gangwon-do, Republic of Korea
| | - Inchan Youn
- Biomedical Research Division, Korea Institute of Science and Technology (KIST), Seoul 02792, Seongbuk-gu, Republic of Korea; Division of Bio-Medical Science & Technology, KIST School, Korea University of Science and Technology (UST), Seoul 02792, Seongbuk-gu, Republic of Korea; KHU-KIST Department of Converging Science and Technology, Kyung Hee University, Seoul 02447, Seongbuk-gu, Republic of Korea
| | - Hyojin Lee
- Biomedical Research Division, Korea Institute of Science and Technology (KIST), Seoul 02792, Seongbuk-gu, Republic of Korea; Division of Bio-Medical Science & Technology, KIST School, Korea University of Science and Technology (UST), Seoul 02792, Seongbuk-gu, Republic of Korea.
| | - Sungmin Han
- Biomedical Research Division, Korea Institute of Science and Technology (KIST), Seoul 02792, Seongbuk-gu, Republic of Korea; Division of Bio-Medical Science & Technology, KIST School, Korea University of Science and Technology (UST), Seoul 02792, Seongbuk-gu, Republic of Korea.
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19
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Hoang TN, Lin HC, Tsai CH, Jan CK, Liu HL. Passive Cavitation Enhancement Mapping via an Ultrasound Dual-Mode phased array to monitor blood-brain barrier opening. J Med Biol Eng 2022. [DOI: 10.1007/s40846-022-00735-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/16/2022]
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20
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The effects and mechanisms of transcranial ultrasound stimulation combined with cognitive rehabilitation on post-stroke cognitive impairment. Neurol Sci 2022; 43:4315-4321. [DOI: 10.1007/s10072-022-05906-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2021] [Accepted: 01/17/2022] [Indexed: 10/19/2022]
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21
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Subasinghe SAAS, Pautler RG, Samee MAH, Yustein JT, Allen MJ. Dual-Mode Tumor Imaging Using Probes That Are Responsive to Hypoxia-Induced Pathological Conditions. BIOSENSORS 2022; 12:bios12070478. [PMID: 35884281 PMCID: PMC9313010 DOI: 10.3390/bios12070478] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/19/2022] [Revised: 06/22/2022] [Accepted: 06/26/2022] [Indexed: 05/02/2023]
Abstract
Hypoxia in solid tumors is associated with poor prognosis, increased aggressiveness, and strong resistance to therapeutics, making accurate monitoring of hypoxia important. Several imaging modalities have been used to study hypoxia, but each modality has inherent limitations. The use of a second modality can compensate for the limitations and validate the results of any single imaging modality. In this review, we describe dual-mode imaging systems for the detection of hypoxia that have been reported since the start of the 21st century. First, we provide a brief overview of the hallmarks of hypoxia used for imaging and the imaging modalities used to detect hypoxia, including optical imaging, ultrasound imaging, photoacoustic imaging, single-photon emission tomography, X-ray computed tomography, positron emission tomography, Cerenkov radiation energy transfer imaging, magnetic resonance imaging, electron paramagnetic resonance imaging, magnetic particle imaging, and surface-enhanced Raman spectroscopy, and mass spectrometric imaging. These overviews are followed by examples of hypoxia-relevant imaging using a mixture of probes for complementary single-mode imaging techniques. Then, we describe dual-mode molecular switches that are responsive in multiple imaging modalities to at least one hypoxia-induced pathological change. Finally, we offer future perspectives toward dual-mode imaging of hypoxia and hypoxia-induced pathophysiological changes in tumor microenvironments.
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Affiliation(s)
| | - Robia G. Pautler
- Department of Integrative Physiology, Baylor College of Medicine, Houston, TX 77030, USA; (R.G.P.); (M.A.H.S.)
| | - Md. Abul Hassan Samee
- Department of Integrative Physiology, Baylor College of Medicine, Houston, TX 77030, USA; (R.G.P.); (M.A.H.S.)
| | - Jason T. Yustein
- Integrative Molecular and Biomedical Sciences and the Department of Pediatrics in the Texas Children’s Cancer and Hematology Centers and The Faris D. Virani Ewing Sarcoma Center, Baylor College of Medicine, Houston, TX 77030, USA;
| | - Matthew J. Allen
- Department of Chemistry, Wayne State University, 5101 Cass Avenue, Detroit, MI 48202, USA;
- Correspondence:
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22
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Thies M, Oelze ML. Combined Therapy Planning, Real-Time Monitoring, and Low Intensity Focused Ultrasound Treatment Using a Diagnostic Imaging Array. IEEE TRANSACTIONS ON MEDICAL IMAGING 2022; 41:1410-1419. [PMID: 34986094 PMCID: PMC9199060 DOI: 10.1109/tmi.2021.3140176] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/25/2023]
Abstract
Low intensity focused ultrasound (FUS) therapies use low intensity focused ultrasound waves, typically in combination with microbubbles, to non-invasively induce a variety of therapeutic effects. FUS therapies require pre-therapy planning and real-time monitoring during treatment to ensure the FUS beam is correctly targeted to the desired tissue region. To facilitate more streamlined FUS treatments, we present a system for pre-therapy planning, real-time FUS beam visualization, and low intensity FUS treatment using a single diagnostic imaging array. Therapy planning was accomplished by manually segmenting a B-mode image captured by the imaging array and calculating a sonication pattern for the treatment based on the user-input region of interest. For real-time monitoring, the imaging array transmitted a visualization pulse which was focused to the same location as the FUS therapy beam and ultrasonic backscatter from this pulse was used to reconstruct the intensity field of the FUS beam. The therapy planning and beam monitoring techniques were demonstrated in a tissue-mimicking phantom and in a rat tumor in vivo while a mock FUS treatment was carried out. The FUS pulse from the imaging array was excited with an MI of 0.78, which suggests that the array could be used to administer select low intensity FUS treatments involving microbubble activation.
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23
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Vasan A, Allein F, Duque M, Magaram U, Boechler N, Chalasani SH, Friend J. Microscale concert hall acoustics to produce uniform ultrasound stimulation for targeted sonogenetics in hsTRPA1-transfected cells. ADVANCED NANOBIOMED RESEARCH 2022; 2:2100135. [PMID: 36060550 PMCID: PMC9431988 DOI: 10.1002/anbr.202100135] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
Abstract
The field of ultrasound neuromodulation has rapidly developed over the past decade, a consequence of the discovery of strain-sensitive structures in the membrane and organelles of cells extending into the brain, heart, and other organs. Notably, clinical trials are underway for treating epilepsy using focused ultrasound to elicit an organized local electrical response. A key limitation to this approach is the formation of standing waves within the skull. In standing acoustic waves, the maximum ultrasound intensity spatially varies from near zero to double the mean in one half a wavelength, and has lead to localized tissue damage and disruption of normal brain function while attempting to evoke a broader response. This phenomenon also produces a large spatial variation in the actual ultrasound exposure in tissue, leading to heterogeneous results and challenges with interpreting these effects. One approach to overcome this limitation is presented herein: transducer-mounted diffusers that result in spatiotemporally incoherent ultrasound. Herein, we numerically and experimentally quantified the effect of a diffuser in an enclosed domain, and show that adding the diffuser leads to a two-fold increase in ultrasound responsiveness of hsTRPA1 transfected HEK cells. Furthermore, we demonstrate the diffuser allow us to produce an uniform spatial distribution of pressure in the rodent skull. Collectively, we propose that our approach leads to a means to deliver uniform ultrasound into irregular cavities for sonogenetics.
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Affiliation(s)
- Aditya Vasan
- Medically Advanced Devices Laboratory, Department of Mechanical and Aerospace Engineering, Jacobs School of Engineering and Department of Surgery, School of Medicine, University of California San Diego, La Jolla CA 92093 USA
| | - Florian Allein
- Department of Mechanical and Aerospace Engineering, University of California San Diego, La Jolla CA 92093 USA
| | - Marc Duque
- Molecular Neurobiology Laboratory, The Salk Institute for Biological Studies, La Jolla, CA 92037
| | - Uri Magaram
- Molecular Neurobiology Laboratory, The Salk Institute for Biological Studies, La Jolla, CA 92037
| | - Nicholas Boechler
- Department of Mechanical and Aerospace Engineering, University of California San Diego, La Jolla CA 92093 USA
| | - Sreekanth H Chalasani
- Molecular Neurobiology Laboratory, The Salk Institute for Biological Studies, La Jolla, CA 92037
| | - James Friend
- Medically Advanced Devices Laboratory, Department of Mechanical and Aerospace Engineering, Jacobs School of Engineering and Department of Surgery, School of Medicine, University of California San Diego, La Jolla CA 92093 USA
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24
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Barbato G, Nisticò R, Triaca V. Exploiting Focused Ultrasound to Aid Intranasal Drug Delivery for Brain Therapy. Front Pharmacol 2022; 13:786475. [PMID: 35496270 PMCID: PMC9046653 DOI: 10.3389/fphar.2022.786475] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2021] [Accepted: 03/07/2022] [Indexed: 11/13/2022] Open
Abstract
Novel effective therapeutic strategies are needed to treat brain neurodegenerative diseases and to improve the quality of life of patients affected by Alzheimer’s disease (AD), Parkinson’s disease (PD), Huntington’s disease (HD), Amyotrophic Lateral sclerosis (ALS) as well as other brain conditions. At present no effective treatment options are available; current therapeutics for neurodegenerative diseases (NDs) improve cognitive symptoms only transiently and in a minor number of patients. Further, most of the amyloid-based phase III clinical trials recently failed in AD, in spite of promising preclinical and phase I-II clinical trials, further pinpointing the need for a better knowledge of the early mechanisms of disease as well as of more effective routes of drug administration. In fact, beyond common pathological events and molecular substrates, each of these diseases preferentially affect defined subpopulations of neurons in specific neuronal circuits (selective neuronal vulnerability), leading to the typical age-related clinical profile. In this perspective, key to successful drug discovery is a robust and reproducible biological validation of potential new molecular targets together with a concomitant set up of protocols/tools for efficient and targeted brain delivery to a specific area of interest. Here we propose and discuss Focused UltraSound aided drug administration as a specific and novel technical approach to achieve optimal concentration of the drug at the target area of interest. We will focus on drug delivery to the brain through the nasal route coupled to FUS as a promising approach to achieve neuroprotection and rescue of cognitive decline in several NDs.
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Affiliation(s)
- Gaetano Barbato
- Inno-Sol Srl, Rome, Italy
- Department of Biology, School of Pharmacy, University of Tor Vergata, Rome, Italy
- *Correspondence: Gaetano Barbato, ; Robert Nisticò, ; Viviana Triaca,
| | - Robert Nisticò
- Department of Biology, School of Pharmacy, University of Tor Vergata, Rome, Italy
- Laboratory of Pharmacology of Synaptic Plasticity, Fondazione EBRI Rita Levi Montalcini, Rome, Italy
- *Correspondence: Gaetano Barbato, ; Robert Nisticò, ; Viviana Triaca,
| | - Viviana Triaca
- Institute of Biochemistry and Cell Biology (IBBC), National Research Council (CNR), International Campus A. Buzzati-Traverso, Rome, Italy
- *Correspondence: Gaetano Barbato, ; Robert Nisticò, ; Viviana Triaca,
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25
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Gandhi K, Barzegar-Fallah A, Banstola A, Rizwan SB, Reynolds JNJ. Ultrasound-Mediated Blood-Brain Barrier Disruption for Drug Delivery: A Systematic Review of Protocols, Efficacy, and Safety Outcomes from Preclinical and Clinical Studies. Pharmaceutics 2022; 14:pharmaceutics14040833. [PMID: 35456667 PMCID: PMC9029131 DOI: 10.3390/pharmaceutics14040833] [Citation(s) in RCA: 21] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2022] [Revised: 04/03/2022] [Accepted: 04/06/2022] [Indexed: 01/27/2023] Open
Abstract
Ultrasound-mediated blood-brain barrier (BBB) disruption has garnered focus as a method of delivering normally impenetrable drugs into the brain. Numerous studies have investigated this approach, and a diverse set of ultrasound parameters appear to influence the efficacy and safety of this approach. An understanding of these findings is essential for safe and reproducible BBB disruption, as well as in identifying the limitations and gaps for further advancement of this drug delivery approach. We aimed to collate and summarise protocols and parameters for achieving ultrasound-mediated BBB disruption in animal and clinical studies, as well as the efficacy and safety methods and outcomes associated with each. A systematic search of electronic databases helped in identifying relevant, included studies. Reference lists of included studies were further screened to identify supplemental studies for inclusion. In total, 107 articles were included in this review, and the following parameters were identified as influencing efficacy and safety outcomes: microbubbles, transducer frequency, peak-negative pressure, pulse characteristics, and the dosing of ultrasound applications. Current protocols and parameters achieving ultrasound-mediated BBB disruption, as well as their associated efficacy and safety outcomes, are identified and summarised. Greater standardisation of protocols and parameters in future preclinical and clinical studies is required to inform robust clinical translation.
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Affiliation(s)
- Kushan Gandhi
- Department of Anatomy, School of Biomedical Sciences, University of Otago, Dunedin 9016, New Zealand; (K.G.); (A.B.-F.); (A.B.)
- Brain Health Research Centre, University of Otago, Dunedin 9016, New Zealand;
| | - Anita Barzegar-Fallah
- Department of Anatomy, School of Biomedical Sciences, University of Otago, Dunedin 9016, New Zealand; (K.G.); (A.B.-F.); (A.B.)
- Brain Health Research Centre, University of Otago, Dunedin 9016, New Zealand;
| | - Ashik Banstola
- Department of Anatomy, School of Biomedical Sciences, University of Otago, Dunedin 9016, New Zealand; (K.G.); (A.B.-F.); (A.B.)
- Brain Health Research Centre, University of Otago, Dunedin 9016, New Zealand;
| | - Shakila B. Rizwan
- Brain Health Research Centre, University of Otago, Dunedin 9016, New Zealand;
- School of Pharmacy, University of Otago, Dunedin 9016, New Zealand
| | - John N. J. Reynolds
- Department of Anatomy, School of Biomedical Sciences, University of Otago, Dunedin 9016, New Zealand; (K.G.); (A.B.-F.); (A.B.)
- Brain Health Research Centre, University of Otago, Dunedin 9016, New Zealand;
- Correspondence: ; Tel.: +64-3479-5781; Fax: +64-3479-7254
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Dadgar MM, Hynynen K. High-Pressure Low-Frequency Lateral Mode Phased-Array Transducer System for the Treatment of Deep Vein Thrombosis: An In Vitro Study. IEEE TRANSACTIONS ON ULTRASONICS, FERROELECTRICS, AND FREQUENCY CONTROL 2022; 69:1088-1099. [PMID: 35020593 DOI: 10.1109/tuffc.2022.3141871] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/14/2023]
Abstract
Deep vein thrombosis (DVT) can lead to a fatal disease known as pulmonary embolism. Application of high-power ultrasound has been successful in studies to mechanically fragment the clots. Single-element ultrasound transducers were used in most of the studies. Challenges associated with phased arrays, such as high electrical impedance and element breakdown at high voltages, were addressed in the previous study, and a high-power 64-element transducer module was designed and fabricated. In this study, a cylindrical array of 16 modules with the frequency of 260 kHz was modeled and constructed for DVT thrombolysis. The maximum pressure, focal size, and steering ability of the array were examined. In vitro experiments were conducted to assess the performance of the array. The simulated pressure amplitude of 34 MPa at the depth of 55 mm (average femoral vein (FV) distance from the inner surface of the thigh) was in consistent with the experiments and satisfied the purpose of this study. Moreover, the employed module distribution resulted in a focal spot dimension of 2.4×2.8×7.3 mm3 (at the 75% pressure amplitude level) that can be confined in a human FV with the average diameter of 12 mm. In vitro experiments manifested a partial and complete clot breakdown at 11.5- and 15-MPa pressure at the focus. The design and engineering of the array system was succeeded in maintaining the desired pressure and focal size even when steered. The results presented in this study suggest the potential of the designed array system for clinical applications.
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Hosseini M, Pierre K, Felisma P, Mampre D, Stein A, Fusco A, Reddy R, Chandra V, Lucke-Wold B. Focused ultrasound: Innovation in use for neurologic conditions. TRAUMA AND EMERGENCY MEDICINE 2022; 1:1-12. [PMID: 36745142 PMCID: PMC9897206] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Figures] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Focused ultrasound has emerged as a key tool for neurologic disorders. In this focused review, we discuss the utility in disrupting the blood brain barrier to maximize treatment. This can facilitate creating direct coagulative lesions and aid in the administration of chemotherapy. Furthermore, it can facilitate neuromodulation when used in pulse sequencing. The current literature regarding brain tumors, essential tremor, and obsessive-compulsive disorder is reviewed. Additionally, concepts and experimental outcomes for neurodegenerative disease such as Alzheimer's is presented. Focused ultrasound as a tool is still in its infancy but the potential for adjuvant and direct therapy is promising. More clinical uses will become apparent in coming decades.
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Affiliation(s)
- Mohammad Hosseini
- Department of Neurosurgery, University of Florida, Gainesville, FL 32608, USA
| | - Kevin Pierre
- Department of Neurosurgery, University of Florida, Gainesville, FL 32608, USA
| | - Patrick Felisma
- Department of Neurosurgery, University of Florida, Gainesville, FL 32608, USA
| | - David Mampre
- Department of Neurosurgery, University of Florida, Gainesville, FL 32608, USA
| | - Allison Stein
- Department of Neurosurgery, University of Florida, Gainesville, FL 32608, USA
| | - Anna Fusco
- Department of Neurosurgery, University of Florida, Gainesville, FL 32608, USA
| | - Ramya Reddy
- Department of Neurosurgery, University of Florida, Gainesville, FL 32608, USA
| | - Vyshak Chandra
- Department of Neurosurgery, University of Florida, Gainesville, FL 32608, USA
| | - Brandon Lucke-Wold
- Department of Neurosurgery, University of Florida, Gainesville, FL 32608, USA
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Zhou X, Wang Y, Li Y, Zhao Y, Shan T, Gong X, Li F, Tang MX, Wang Z. Acoustic beam mapping for guiding HIFU therapy in vivo using sub-therapeutic sound pulse and passive beamforming. IEEE Trans Biomed Eng 2021; 69:1663-1673. [PMID: 34752379 DOI: 10.1109/tbme.2021.3126734] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Abstract
OBJECTIVE Although HIFU has been successfully applied in various clinical applications in the past two decades for the ablation of many types of tumors, one bottleneck in its wider applications is the lack of a reliable and affordable strategy to guide the therapy. This study aims at estimating the therapeutic beam path at the pre-treatment stage to guide the therapeutic procedure. METHODS An incident beam mapping technique using passive beamforming was proposed based on a clinical HIFU system and an ultrasound imaging research system. An optimization model was created to map the cross-like beam pattern by maximizing the total energy within the mapped area. This beam mapping technique was validated by comparing the estimated focal region with the HIFU-induced actual focal region (damaged region) through simulation, in-vitro, ex-vivo and in-vivo experiments. RESULTS The results of this study showed that the proposed technique was, to a large extent, tolerant of sound speed inhomogeneities, being able to estimate the focal location with errors of 0.15 mm and 0.93 mm under in-vitro and ex-vivo situations respectively, and slightly over 1 mm under the in-vivo situation. It should be noted that the corresponding errors were 6.8 mm, 3.2 mm, and 9.9 mm respectively when the conventional geometrical method was used. CONCLUSION This beam mapping technique can be very helpful in guiding the HIFU therapy and can be easily applied in clinical environments with an ultrasound-guided HIFU system. SIGNIFICANCE The technique is non-invasive and can potentially be adapted to other ultrasound-related beam manipulating applications.
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Tretbar SH, Fournelle M, Speicher D, Becker FJ, Anastasiadis P, Landgraf L, Roy U, Melzer A. A novel matrix-array-based MR-conditional ultrasound system for local hyperthermia of small animals. IEEE Trans Biomed Eng 2021; 69:758-770. [PMID: 34398748 DOI: 10.1109/tbme.2021.3104865] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Abstract
OBJECTIVE The goal of this work was to develop a novel modular focused ultrasound hyperthermia (FUS-HT) system for preclinical applications with the following characteristics: MR-compatible, compact probe for integration into a PET/MR small animal scanner, 3D-beam steering capabilities, high resolution focusing for generation of spatially confined FUS-HT effects. METHODS For 3D-beam steering capabilities, a matrix array approach with 11 11 elements was chosen. For reaching the required level of integration, the array was mounted with a conductive backing directly on the interconnection PCB. The array is driven by a modified version of our 128 channel ultrasound research platform DiPhAS. The system was characterized using sound field measurements and validated using tissue-mimicking phantoms. Preliminary MR-compatibility tests were performed using a 7T Bruker MRI scanner. RESULTS Four 11 11 arrays between 0.5 and 2 MHz were developed and characterized with respect to sound field properties and HT generation. Focus sizes between 1 and 4 mm were reached depending on depth and frequency. We showed heating by 4C within 60 s in phantoms. The integration concept allows a probe thickness of less than 12 mm. CONCLUSION We demonstrated FUS-HT capabilities of our modular system based on matrix arrays and a 128 channel electronics system within a 3D-steering range of up to 30. The suitability for integration into a small animal MR could be demonstrated in basic MR-compatibility tests. SIGNIFICANCE The developed system presents a new generation of FUS-HT for preclinical and translational work providing safe, reversible, localized, and controlled HT.
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Payne A, Chopra R, Ellens N, Chen L, Ghanouni P, Sammet S, Diederich C, Ter Haar G, Parker D, Moonen C, Stafford J, Moros E, Schlesinger D, Benedict S, Wear K, Partanen A, Farahani K. AAPM Task Group 241: A medical physicist's guide to MRI-guided focused ultrasound body systems. Med Phys 2021; 48:e772-e806. [PMID: 34224149 DOI: 10.1002/mp.15076] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2020] [Revised: 04/28/2021] [Accepted: 06/21/2021] [Indexed: 11/07/2022] Open
Abstract
Magnetic resonance-guided focused ultrasound (MRgFUS) is a completely non-invasive technology that has been approved by FDA to treat several diseases. This report, prepared by the American Association of Physicist in Medicine (AAPM) Task Group 241, provides background on MRgFUS technology with a focus on clinical body MRgFUS systems. The report addresses the issues of interest to the medical physics community, specific to the body MRgFUS system configuration, and provides recommendations on how to successfully implement and maintain a clinical MRgFUS program. The following sections describe the key features of typical MRgFUS systems and clinical workflow and provide key points and best practices for the medical physicist. Commonly used terms, metrics and physics are defined and sources of uncertainty that affect MRgFUS procedures are described. Finally, safety and quality assurance procedures are explained, the recommended role of the medical physicist in MRgFUS procedures is described, and regulatory requirements for planning clinical trials are detailed. Although this report is limited in scope to clinical body MRgFUS systems that are approved or currently undergoing clinical trials in the United States, much of the material presented is also applicable to systems designed for other applications.
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Affiliation(s)
- Allison Payne
- Department of Radiology and Imaging Sciences, University of Utah, Salt Lake City, UT, USA
| | - Rajiv Chopra
- Department of Radiology, UT Southwestern Medical Center, Dallas, TX, USA
| | | | - Lili Chen
- Department of Radiation Oncology, Fox Chase Cancer Center, Philadelphia, PA, USA
| | - Pejman Ghanouni
- Department of Radiology, Stanford University, Stanford, CA, USA
| | - Steffen Sammet
- Department of Radiology, University of Chicago, Chicago, IL, USA
| | - Chris Diederich
- Department of Radiation Oncology, University of California San Francisco, San Francisco, CA, USA
| | | | - Dennis Parker
- Department of Radiology and Imaging Sciences, University of Utah, Salt Lake City, UT, USA
| | - Chrit Moonen
- Imaging Division, University Medical Center Utrecht, Utrecht, The Netherlands
| | - Jason Stafford
- Department of Imaging Physics, MD Anderson Cancer Center, Houston, TX, USA
| | - Eduardo Moros
- Department of Radiation Oncology, Moffitt Cancer Center, Tampa, FL, USA
| | - David Schlesinger
- Department of Radiation Oncology, University of Virginia, Charlottesville, VA, USA
| | | | - Keith Wear
- U.S. Food and Drug Administration, Silver Spring, MD, USA
| | | | - Keyvan Farahani
- National Cancer Institute, National Institutes of Health, Rockville, MD, USA
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Liang S, Zhang Z, Wang X, Su M, Qiu W, Zheng H. Flexible Pico-Liter Acoustic Droplet Ejection Based on High-Frequency Ultrasound Transducer. IEEE TRANSACTIONS ON ULTRASONICS, FERROELECTRICS, AND FREQUENCY CONTROL 2021; 68:2212-2218. [PMID: 33591916 DOI: 10.1109/tuffc.2021.3059904] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
Acoustic droplet ejection (ADE) uses the acoustic energy produced by a focused ultrasound beam to provide a noncontact, highly precise, automatic, and cost-effective liquid transfer method for life science applications. The reported minimum precision of the current acoustic liquid transfer technology is 1 nL. Since precision improvement always brings valuable results in biological research, it is highly necessary to develop pico-liter precision liquid transfer technology. In this work, we developed a 40-MHz ultrahigh -frequency focused ultrasound transducer with a large aperture of 7×7 mm2 and a wide bandwidth of 76.4%. The designed transducer can successfully eject pico-liter droplets, and the droplet ejection accuracy ranges from 28 to 439 pL. The effects of the acoustic parameters, including excitation amplitude, pulsewidth, and frequency, on the size of the ejected droplet were studied. A wide range of ejected droplet sizes could be obtained by adjusting the acoustic parameters, thereby making liquid transfer flexible. The flexible pico-liter liquid transfer based on the wide-bandwidth, high-frequency ultrasound transducer is easier to achieve automatically, and thus it has broad prospects in biological research and industrial applications.
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32
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Adams C, Jones RM, Yang SD, Kan WM, Leung K, Zhou Y, Lee KU, Huang Y, Hynynen K. Implementation of a Skull-Conformal Phased Array for Transcranial Focused Ultrasound Therapy. IEEE Trans Biomed Eng 2021; 68:3457-3468. [PMID: 33950835 DOI: 10.1109/tbme.2021.3077802] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
OBJECTIVE To implement a skull-conformal phased array for ultrasound-guided transcranial focused ultrasound therapy with improved patient comfort. METHODS Using patient-specific computed tomography and MRI neuroimaging data, tightly-conforming helmet scaffolds were designed computationally. The helmet scaffolds were designed to hold reusable transducer modules at near-normal incidence in an optimal configuration for the treatment location(s) of interest. Numerical simulations of trans-skull ultrasound propagation were performed to evaluate different conformal array designs and to compare with hemispherical arrays similar to those employed clinically. A 4096-element phased array was constructed by 3D printing a helmet scaffold optimised for an ex vivo human skullcap, and its performance was evaluated via benchtop and in vivo experiments. RESULTS Acoustic field measurements confirmed the system's ability to focus through human skull bone using simulation-based transcranial aberration corrections. Preliminary in vivo testing demonstrated safe trans-human skull blood-brain barrier (BBB) opening in rodents. CONCLUSION Patient-specific conformal ultrasound phased arrays appear to be a feasible and safe approach for conducting transcranial BBB opening procedures. SIGNIFICANCE Skull-conformal phased arrays stand to improve patient comfort and have the potential to accelerate the adoption of transcranial FUS therapy by improving access to the technology.
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Bawiec CR, Khokhlova TD, Sapozhnikov OA, Rosnitskiy PB, Cunitz BW, Ghanem MA, Hunter C, Kreider W, Schade GR, Yuldashev PV, Khokhlova VA. A Prototype Therapy System for Boiling Histotripsy in Abdominal Targets Based on a 256-Element Spiral Array. IEEE TRANSACTIONS ON ULTRASONICS, FERROELECTRICS, AND FREQUENCY CONTROL 2021; 68:1496-1510. [PMID: 33156788 PMCID: PMC8191454 DOI: 10.1109/tuffc.2020.3036580] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/07/2023]
Abstract
Boiling histotripsy (BH) uses millisecond-long ultrasound (US) pulses with high-amplitude shocks to mechanically fractionate tissue with potential for real-time lesion monitoring by US imaging. For BH treatments of abdominal organs, a high-power multielement phased array system capable of electronic focus steering and aberration correction for body wall inhomogeneities is needed. In this work, a preclinical BH system was built comprising a custom 256-element 1.5-MHz phased array (Imasonic, Besançon, France) with a central opening for mounting an imaging probe. The array was electronically matched to a Verasonics research US system with a 1.2-kW external power source. Driving electronics and software of the system were modified to provide a pulse average acoustic power of 2.2 kW sustained for 10 ms with a 1-2-Hz repetition rate for delivering BH exposures. System performance was characterized by hydrophone measurements in water combined with nonlinear wave simulations based on the Westervelt equation. Fully developed shocks of 100-MPa amplitude are formed at the focus at 275-W acoustic power. Electronic steering capabilities of the array were evaluated for shock-producing conditions to determine power compensation strategies that equalize BH exposures at multiple focal locations across the planned treatment volume. The system was used to produce continuous volumetric BH lesions in ex vivo bovine liver with 1-mm focus spacing, 10-ms pulselength, five pulses/focus, and 1% duty cycle.
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Zhang Z, Liu R, Li G, Su M, Li F, Zheng H, Qiu W. A Dual-mode 2D Matrix Array for Ultrasound Image-guided Noninvasive Therapy. IEEE Trans Biomed Eng 2021; 68:3482-3490. [PMID: 33872140 DOI: 10.1109/tbme.2021.3073951] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
Focused ultrasound (FUS) lacks reliable real-time image guidance, which hinders the development of non-invasive ultrasound treatment in many important clinical applications. A dual-mode ultrasound array, capable of both imaging and therapy offers a new and reliable strategy for image-guided ultrasound therapy applications. The strategy has the advantages of real-time use, low cost, portability and inherent registration between imaging and therapeutic coordinate systems. In this work, a dual-mode two-dimensional (2D) matrix array with 1 MHz center frequency and 256 elements for ultrasound image-guided non-invasive therapy is reported. The array can provide three-dimensional (3D) volumetric ultrasound imaging and 3D focus control. Ultrasound imaging and therapeutic applications for the brain of small animals demonstrated the multi-functional capability of the dual-mode 2D matrix array. A method of rat brain positioning based on ultrasound imaging was proposed and verified. Transcranial ultrasound image-guided bloodbrain barrier (BBB) opening of multiple-targets was achieved in vivo, using the proposed dual-mode 2D array. The obtained results indicate that the dual-mode 2D matrix array is a promising method for practical use in ultrasound image-guided non-invasive therapy applications.
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35
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Martin E, Roberts M, Treeby B. Measurement and simulation of steered acoustic fields generated by a multielement array for therapeutic ultrasound. JASA EXPRESS LETTERS 2021; 1:012001. [PMID: 33763661 PMCID: PMC7610400 DOI: 10.1121/10.0003210] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
Modelling of fields generated by therapeutic ultrasound arrays can be prone to errors arising from differences from nominal transducer parameters, and variations in relative outputs of array elements when driven under different conditions, especially when simulating steered fields. Here, the effect of element size, element positions, relative source pressure variations, and electrical crosstalk on the accuracy of modelling pressure fields generated by a 555 kHz 32-element ultrasonic array were investigated. For this transducer, errors in pressure amplitude and focal position were respectively reduced from 20% to 4% and 3.3 mm to 1.5 mm using crosstalk prediction, and experimentally determined positions.
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Affiliation(s)
- Eleanor Martin
- Wellcome/EPSRC Centre for Interventional & Surgical Sciences (WEISS), University College London, London, United Kingdom
| | - Morgan Roberts
- Department of Medical Physics and Biomedical Engineering, University College London, London, United Kingdom
| | - Bradley Treeby
- Department of Medical Physics and Biomedical Engineering, University College London, London, United Kingdom
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Rahimi S, Jones RM, Hynynen K. A High-Frequency Phased Array System for Transcranial Ultrasound Delivery in Small Animals. IEEE TRANSACTIONS ON ULTRASONICS, FERROELECTRICS, AND FREQUENCY CONTROL 2021; 68:127-135. [PMID: 32746231 PMCID: PMC7863589 DOI: 10.1109/tuffc.2020.3012868] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
Existing systems for applying transcranial focused ultrasound (FUS) in small animals produce large focal volumes relative to the size of cerebral structures available for interrogation. The use of high ultrasonic frequencies can improve targeting specificity; however, the aberrations induced by rodent calvaria at megahertz frequencies severely distort the acoustic fields produced by single-element focused transducers. Here, we present the design, fabrication, and characterization of a high-frequency phased array system for transcranial FUS delivery in small animals. A transducer array was constructed by micromachining a spherically curved PZT-5H bowl (diameter = 25 mm, radius of curvature = 20 mm, fundamental frequency = 3.3 MHz) into 64 independent elements of equal surface area. The acoustic field generated by the phased array was measured at various target locations using a calibrated fiber-optic hydrophone, both in free-field conditions as well as through ex vivo rat skullcaps with and without hydrophone-assisted phase aberration corrections. Large field-of-view acoustic field simulations were carried out to investigate potential grating lobe formation. The focal beam size obtained when targeting the array's geometric focus was [Formula: see text] mm in water. The array can steer the FUS beam electronically over cylindrical volumes of 4.5 mm in diameter and 6 mm in height without introducing grating lobes. Insertion of a rat skullcap resulted in substantial distortion of the acoustic field ( [Formula: see text]% [Formula: see text]); however, phase corrections restored partial focal quality ( [Formula: see text]% [Formula: see text]). Using phase corrections, the array is capable of generating a trans-rat skull peak negative focal pressure of up to ~2.0 MPa, which is sufficient for microbubble-mediated blood-brain barrier permeabilization at this frequency.
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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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38
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Dadgar MM, Hynynen K. High-Power Phased-Array Transducer Module for the Construction of a System for the Treatment of Deep Vein Thrombosis. IEEE TRANSACTIONS ON ULTRASONICS, FERROELECTRICS, AND FREQUENCY CONTROL 2020; 67:2710-2716. [PMID: 32746223 DOI: 10.1109/tuffc.2020.3011666] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
Blood clot can be disintegrated by high-intensity focused ultrasound alone through inertial cavitation. There are limitations in using single-element ultrasound transducers for this purpose such as lack of steerability and control of the focus in terms of shape and location. Phased-array transducers being able to rapidly scan over the clots can alleviate this problem. A full 3-D control of the ultrasound beam can be achieved by 2-D electronically steerable arrays. However, the required high-pressure amplitude has not been possible with such arrays. In this work, a 2-D 64-element fully populated phased-array transducer module was designed and fabricated for the high-pressure amplitude required for deep vein thrombosis (DVT). Lateral coupling was considered for the transducer design to decrease the electrical impedance and eliminate the need for electrical matching circuit. PZT-4 with a thickness of 0.35 mm, an element surface area of [Formula: see text] mm, and a length of 6 mm showed a mean electrical impedance of 60.4 ± 11.5 measured for each transducer element facilitating effective electric power transfer from the driving electronics. No breakdown was observed when the voltage was increased gradually to 180 ± 3 Vpp. Operation at 180 Vpp was found to be safe over 10,000 repetitions without reduction in the power, resulting in the average pressure amplitude of 1.01 ± 0.09 MPa at 2 mm from the element surface. These pressure amplitude values indicate that an array of eight modules (80 [Formula: see text] mm) is required to reach to the pressure amplitude needed for DVT. Such arrays are practical with the current technology.
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Kumar SU, Telichko AV, Wang H, Hyun D, Johnson EG, Kent MS, Rebhun RB, Dahl JJ, Culp WTN, Paulmurugan R. Acoustically Driven Microbubbles Enable Targeted Delivery of microRNA-Loaded Nanoparticles to Spontaneous Hepatocellular Neoplasia in Canines. ADVANCED THERAPEUTICS 2020; 3:2000120. [PMID: 33415184 PMCID: PMC7784952 DOI: 10.1002/adtp.202000120] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2020] [Indexed: 01/16/2023]
Abstract
Spatially localized microbubble cavitation by ultrasound offers an effective means of altering permeability of natural barriers (i.e. blood vessel and cell membrane) in favor of nanomaterials accumulation in the target site. In this study, a clinically relevant, minimally invasive ultrasound guided therapeutic approach is investigated for targeted delivery of anticancer microRNA loaded PLGA-b-PEG nanoparticles to spontaneous hepatocellular neoplasia in a canine model. Quantitative assessment of the delivered microRNAs revealed prominent and consistent increase in miRNAs levels (1.5-to 2.3-fold increase (p<0.001)) in ultrasound treated tumor regions compared to untreated control regions. Immunohistology of ultrasound treated tumor tissue presented a clear evidence for higher amount of nanoparticles extravasation from the blood vessels. A distinct pattern of cytokine expression supporting CD8+ T cells mediated "cold-to-hot" tumor transition was evident in all patients. On the outset, proposed platform can enhance delivery of miRNA-loaded nanoparticles to deep seated tumors in large animals to enhance chemotherapy.
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Affiliation(s)
- Sukumar Uday Kumar
- Molecular Imaging Program at Stanford (MIPS), Stanford University, Stanford, California; Department of Radiology, Stanford University, Stanford, California
| | - Arsenii V Telichko
- Molecular Imaging Program at Stanford (MIPS), Stanford University, Stanford, California; Department of Radiology, Stanford University, Stanford, California
| | - Huaijun Wang
- Molecular Imaging Program at Stanford (MIPS), Stanford University, Stanford, California; Department of Radiology, Stanford University, Stanford, California
| | - Dongwoon Hyun
- Molecular Imaging Program at Stanford (MIPS), Stanford University, Stanford, California; Department of Radiology, Stanford University, Stanford, California
| | - Eric G Johnson
- Department of Surgical and Radiological Sciences, School of Veterinary Medicine, University of California, Davis, California
| | - Michael S Kent
- Department of Surgical and Radiological Sciences, School of Veterinary Medicine, University of California, Davis, California
| | - Robert B Rebhun
- Department of Surgical and Radiological Sciences, School of Veterinary Medicine, University of California, Davis, California
| | - Jeremy J Dahl
- Molecular Imaging Program at Stanford (MIPS), Stanford University, Stanford, California; Department of Radiology, Stanford University, Stanford, California
| | - William T N Culp
- Department of Surgical and Radiological Sciences, School of Veterinary Medicine, University of California, Davis, California
| | - Ramasamy Paulmurugan
- Molecular Imaging Program at Stanford (MIPS), Stanford University, Stanford, California; Department of Radiology, Stanford University, Stanford, California
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Hofstetter LW, Fausett L, Mueller A, Odéen H, Payne A, Christensen DA, Parker DL. Development and characterization of a tissue mimicking psyllium husk gelatin phantom for ultrasound and magnetic resonance imaging. Int J Hyperthermia 2020; 37:283-290. [PMID: 32204632 DOI: 10.1080/02656736.2020.1739345] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022] Open
Abstract
Purpose: To develop and characterize a tissue-mimicking phantom that enables the direct comparison of magnetic resonance (MR) and ultrasound (US) imaging techniques useful for monitoring high-intensity focused ultrasound (HIFU) treatments. With no additions, gelatin phantoms produce little if any scattering required for US imaging. This study characterizes the MR and US image characteristics as a function of psyllium husk concentration, which was added to increase US scattering.Methods: Gelatin phantoms were constructed with varying concentrations of psyllium husk. The effects of psyllium husk concentration on US B-mode and MR imaging were evaluated at nine different concentrations. T1, T2, and T2* MR maps were acquired. Acoustic properties (attenuation and speed of sound) were measured at frequencies of 0.6, 1.0, 1.8, and 3.0 MHz using a through-transmission technique. Phantom elastic properties were evaluated for both time and temperature dependence.Results: Ultrasound image echogenicity increased with increasing psyllium husk concentration while quality of gradient-recalled echo MR images decreased with increasing concentration. For all phantoms, the measured speed of sound ranged between 1567-1569 m/s and the attenuation ranged between 0.42-0.44 dB/(cm·MHz). Measured T1 ranged from 974-1051 ms. The T2 and T2* values ranged from 97-108 ms and 48-88 ms, respectively, with both showing a decreasing trend with increased psyllium husk concentration. Phantom stiffness, measured using US shear-wave speed measurements, increased with age and decreased with increasing temperature.Conclusions: The presented dual-use tissue-mimicking phantom is easy to manufacture and can be used to compare and evaluate US-guided and MR-guided HIFU imaging protocols.
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Affiliation(s)
- Lorne W Hofstetter
- Department of Radiology and Imaging Sciences, University of Utah, Salt Lake City, UT, USA
| | - Lewis Fausett
- Department of Radiology and Imaging Sciences, University of Utah, Salt Lake City, UT, USA
| | - Alexander Mueller
- Department of Radiology and Imaging Sciences, University of Utah, Salt Lake City, UT, USA
| | - Henrik Odéen
- Department of Radiology and Imaging Sciences, University of Utah, Salt Lake City, UT, USA
| | - Allison Payne
- Department of Radiology and Imaging Sciences, 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
| | - Dennis L Parker
- Department of Radiology and Imaging Sciences, University of Utah, Salt Lake City, UT, USA
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Meng Y, Hynynen K, Lipsman N. Applications of focused ultrasound in the brain: from thermoablation to drug delivery. Nat Rev Neurol 2020; 17:7-22. [PMID: 33106619 DOI: 10.1038/s41582-020-00418-z] [Citation(s) in RCA: 170] [Impact Index Per Article: 42.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 09/16/2020] [Indexed: 02/07/2023]
Abstract
Focused ultrasound (FUS) is a disruptive medical technology, and its implementation in the clinic represents the culmination of decades of research. Lying at the convergence of physics, engineering, imaging, biology and neuroscience, FUS offers the ability to non-invasively and precisely intervene in key circuits that drive common and challenging brain conditions. The actions of FUS in the brain take many forms, ranging from transient blood-brain barrier opening and neuromodulation to permanent thermoablation. Over the past 5 years, we have seen a dramatic expansion of indications for and experience with FUS in humans, with a resultant exponential increase in academic and public interest in the technology. Applications now span the clinical spectrum in neurological and psychiatric diseases, with insights still emerging from preclinical models and human trials. In this Review, we provide a comprehensive overview of therapeutic ultrasound and its current and emerging indications in the brain. We examine the potential impact of FUS on the landscape of brain therapies as well as the challenges facing further advancement and broader adoption of this promising minimally invasive therapeutic alternative.
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Affiliation(s)
- Ying Meng
- Division of Neurosurgery, Sunnybrook Health Sciences Centre, Toronto, ON, Canada.,Sunnybrook Research Institute, Hurvitz Brain Sciences Program, Harquail Centre for Neuromodulation, Toronto, ON, Canada.,Institute of Medical Sciences, Faculty of Medicine, University of Toronto, Toronto, ON, Canada
| | - Kullervo Hynynen
- Sunnybrook Research Institute, Toronto, ON, Canada.,Department of Medical Biophysics and Institute of Biomaterials & Biomedical Engineering (IBBME), University of Toronto, Toronto, ON, Canada
| | - Nir Lipsman
- Division of Neurosurgery, Sunnybrook Health Sciences Centre, Toronto, ON, Canada. .,Sunnybrook Research Institute, Hurvitz Brain Sciences Program, Harquail Centre for Neuromodulation, Toronto, ON, Canada. .,Institute of Medical Sciences, Faculty of Medicine, University of Toronto, Toronto, ON, Canada.
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Zhang Z, Su M, Li F, Liu R, Cai R, Li G, Jiang Q, Zhong H, Shrout TR, Zhang S, Zheng H, Qiu W. New Sm-PMN-PT Ceramic-Based 2-D Array for Low-Intensity Ultrasound Therapy Application. IEEE TRANSACTIONS ON ULTRASONICS, FERROELECTRICS, AND FREQUENCY CONTROL 2020; 67:2085-2094. [PMID: 32149634 DOI: 10.1109/tuffc.2020.2979471] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
A two-dimensional (2-D) array with a small pitch (approximately 0.5λ in medium) can achieve complete 3-D control of ultrasound beams without grating lobes and enable the generation of multiple focal spots simultaneously, which is a desired tool for noninvasive therapy. However, the large electrical impedance of 2-D array elements owing to their small size results in a low energy transfer efficiency between a 2-D array and an electrical system, thereby limiting their practical applications. This article presents the development of a 1-MHz 256-element 2-D array ultrasonic transducer of low electrical impedance based on a new Sm-doped Pb(Mg1/3Nb2/3)O3-PbTiO3 (Sm-PMN-PT) piezoceramic with ultrahigh dielectric permittivity. The electrical impedance of the array element is decreased by 3.4 times as the Sm-PMN-PT replacing commercial PZT-5H. Consequently, the output acoustic pressure of the 2-D array made of Sm-PMN-PT ceramic is approximately twice that of the 2-D array made of PZT-5H ceramic under the same excitation conditions. Array elements are spaced at a 1.1-mm pitch ( 0.71λ in water), enabling a large steering range of the ultrasound beam. A multiple-target blood-brain barrier opening in vivo is demonstrated using the proposed 2-D array with electronic focusing and steering. The obtained results indicate that the 2-D array made of Sm-PMN-PT ceramic is promising for practical use in low-intensity ultrasound therapy applications.
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Touahri Y, Dixit R, Kofoed RH, Mikloska K, Park E, Raeisossadati R, Markham-Coultes K, David LA, Rijal H, Zhao J, Lynch M, Hynynen K, Aubert I, Schuurmans C. Focused ultrasound as a novel strategy for noninvasive gene delivery to retinal Müller glia. Theranostics 2020; 10:2982-2999. [PMID: 32194850 PMCID: PMC7053200 DOI: 10.7150/thno.42611] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2019] [Accepted: 01/08/2020] [Indexed: 12/14/2022] Open
Abstract
Müller glia are specialized retinal cells with stem cell properties in fish and frogs but not in mammals. Current efforts to develop gene therapies to activate mammalian Müller glia for retinal repair will require safe and effective delivery strategies for recombinant adeno-associated viruses (AAVs), vectors of choice for clinical translation. Intravitreal and subretinal injections are currently used for AAV gene delivery in the eye, but less invasive methods efficiently targeting Müller glia have yet to be developed. Methods: As gene delivery strategies have been more extensively studied in the brain, to validate our vectors, we initially compared the glial tropism of AAV-PHP.eB, an AAV9 that crosses the blood-brain and blood-retinal barriers, for its ability to drive fluorescent protein expression in glial cells in both the brain and retina. We then tested the glial transduction of AAV2/8-GFAP-mCherry, a virus that does not cross blood-brain and blood-retinal barriers, for its effectiveness in transducing Müller glia in murine retinal explants ex vivo. For in vivo assays we used larger rat eyes, performing invasive intravitreal injections, and non-invasive intravenous delivery using focused ultrasound (FUS) (pressure amplitude: 0.360 - 0.84 MPa) and microbubbles (Definity, 0.2 ml/kg). Results: We showed that AAV-PHP.eB carrying a ubiquitous promoter (CAG) and green fluorescent protein (GFP) reporter, readily crossed the blood-brain and blood-retinal barriers after intravenous delivery in mice. However, murine Müller glia did not express GFP, suggesting that they were not transduced by AAV-PHP.eB. We thus tested an AAV2/8 variant, which was selected based on its safety record in multiple clinical trials, adding a glial fibrillary acidic protein (GFAP) promoter and mCherry (red fluorescent protein) reporter. We confirmed the glial specificity of AAV2/8-GFAP-mCherry, showing effective expression of mCherry in astrocytes after intracranial injection in the mouse brain, and of Müller glia in murine retinal explants. For in vivo experiments we switched to rats because of their larger size, injecting AAV2/8-GFAP-mCherry intravitreally, an invasive procedure, demonstrating passage across the inner limiting membrane, leading to Müller glia transduction. We then tested an alternative non-invasive delivery approach targeting a different barrier - the inner blood-retinal-barrier, applying focused ultrasound (FUS) to the retina after intravenous injection of AAV2/8 and microbubbles in rats, using magnetic resonance imaging (MRI) for FUS targeting. FUS permeabilized the rat blood-retinal-barrier and allowed the passage of macromolecules to the retina (Evans blue, IgG, IgM), with minimal extravasation of platelets and red blood cells. Intravenous injection of microbubbles and AAV2/8-GFAP-mCherry followed by FUS resulted in mCherry expression in rat Müller glia. However, systemic delivery of AAV2/8 also had off-target effects, transducing several murine peripheral organs, particularly the liver. Conclusions: Retinal permeabilisation via FUS in the presence of microbubbles is effective for delivering AAV2/8 across the inner blood-retinal-barrier, targeting Müller glia, which is less invasive than intravitreal injections that bypass the inner limiting membrane. However, implementing FUS in the clinic will require a comprehensive consideration of any off-target tropism of the AAV in peripheral organs, combined ideally, with the development of Müller glia-specific promoters.
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Affiliation(s)
- Yacine Touahri
- Biological Sciences Platform, Sunnybrook Research Institute, Toronto, Ontario, Canada
| | - Rajiv Dixit
- Biological Sciences Platform, Sunnybrook Research Institute, Toronto, Ontario, Canada
| | - Rikke Hahn Kofoed
- Biological Sciences Platform, Sunnybrook Research Institute, Toronto, Ontario, Canada
| | - Kristina Mikloska
- Physical Sciences Platform, Sunnybrook Research Institute, Toronto, Ontario, Canada
| | - EunJee Park
- Biological Sciences Platform, Sunnybrook Research Institute, Toronto, Ontario, Canada
- Department of Biochemistry, University of Toronto, Toronto, Ontario, Canada
| | - Reza Raeisossadati
- Biological Sciences Platform, Sunnybrook Research Institute, Toronto, Ontario, Canada
| | - Kelly Markham-Coultes
- Biological Sciences Platform, Sunnybrook Research Institute, Toronto, Ontario, Canada
| | - Luke Ajay David
- Biological Sciences Platform, Sunnybrook Research Institute, Toronto, Ontario, Canada
- Department of Laboratory Medicine and Pathobiology, University of Toronto, Toronto, Ontario, Canada
| | - Hibo Rijal
- Biological Sciences Platform, Sunnybrook Research Institute, Toronto, Ontario, Canada
| | - Jiayi Zhao
- Biological Sciences Platform, Sunnybrook Research Institute, Toronto, Ontario, Canada
| | - Madelaine Lynch
- Biological Sciences Platform, Sunnybrook Research Institute, Toronto, Ontario, Canada
- Department of Laboratory Medicine and Pathobiology, University of Toronto, Toronto, Ontario, Canada
| | - Kullervo Hynynen
- Physical Sciences Platform, Sunnybrook Research Institute, Toronto, Ontario, Canada
- Department of Medical Biophysics, University of Toronto, Toronto, Ontario, Canada
| | - Isabelle Aubert
- Biological Sciences Platform, Sunnybrook Research Institute, Toronto, Ontario, Canada
- Department of Laboratory Medicine and Pathobiology, University of Toronto, Toronto, Ontario, Canada
| | - Carol Schuurmans
- Biological Sciences Platform, Sunnybrook Research Institute, Toronto, Ontario, Canada
- Department of Biochemistry, University of Toronto, Toronto, Ontario, Canada
- Department of Laboratory Medicine and Pathobiology, University of Toronto, Toronto, Ontario, Canada
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Adams C. HIFU Power Monitoring Using Combined Instantaneous Current and Voltage Measurement. IEEE TRANSACTIONS ON ULTRASONICS, FERROELECTRICS, AND FREQUENCY CONTROL 2020; 67:239-247. [PMID: 31514135 PMCID: PMC7030945 DOI: 10.1109/tuffc.2019.2941185] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
During high-intensity focused ultrasound (HIFU) therapy, it is important that the electrical power delivered to the transducer is monitored to avoid underexposure or overexposure, ensure patient safety, and to protect the transducer itself. Due to ease of measurement, the transducer's potential difference may be as an indicator of power delivery. However, even when a transducer's complex impedance is well characterized at small amplitudes and matching networks are used, voltage-only (VO) monitoring cannot account for the presence of drive waveform distortion, changes to the acoustic path, or damage to the transducer. In this study, combined current and voltage (CCV) is proposed as a magnetic resonance imaging (MRI)-compatible, miniature alternative to bidirectional power couplers, which is compatible with switched amplifiers. For CCV power measurement, current probe data were multiplied by the voltage waveform and integrated in the frequency domain. Transducer efficiency was taken into account to predict acoustic power. The technique was validated with a radiation force balance (RFB). When using a typical HIFU transducer and amplifier, VO predictions and acoustic power had a maximum difference of 20%. However, under the same conditions, CCV only had a maximum difference of 5%. The technique was applied to several lesioning experiments and it was shown that when VO was used as a control between two amplifiers, there was up to a 38% difference in lesion area. This greatly reduced to a maximum of 5% once CCV was used instead. These results demonstrate that CCV can accurately predict real-time electrical power delivery, leading to safer HIFU treatments.
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Affiliation(s)
- Chris Adams
- Sunnybrook Research Institute, Toronto, Canada
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46
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Allen SP, Steeves T, Fergusson A, Moore D, Davis RM, Vlaisialjevich E, Meyer CH. Novel acoustic coupling bath using magnetite nanoparticles for MR-guided transcranial focused ultrasound surgery. Med Phys 2019; 46:5444-5453. [PMID: 31605643 DOI: 10.1002/mp.13863] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2019] [Revised: 09/26/2019] [Accepted: 10/08/2019] [Indexed: 01/26/2023] Open
Abstract
PURPOSE Acoustic coupling baths, nominally composed of degassed water, play important roles during transcranial focused ultrasound surgery. However, this large water bolus also degrades the quality of intraoperative magnetic resonance (MR) guidance imaging. In this study, we test the feasibility of using dilute, aqueous magnetite nanoparticle suspensions to suppress these image degradations while preserving acoustic compatibility. We examine the effects of these suspensions on metrics of image quality and acoustic compatibility for two types of transcranial focused ultrasound insonation regimes: low-duty cycle histotripsy procedures and high-duty cycle thermal ablation procedures. METHODS Magnetic resonance guidance imaging was used to monitor thermal ablations of in vitro gel targets using a coupling bath composed of various concentrations of aqueous, suspended, magnetite nanoparticles in a clinical transcranial transducer under stationary and flowing conditions. Thermal deposition was monitored using MR thermometry simultaneous to insonation. Then, using normal degassed water as a coupling bath, various concentrations of aqueous, suspended, magnetite nanoparticles were placed at the center of this same transducer and insonated using high-duty cycle pulsing parameters. Passive cavitation detectors recorded cavitation emissions, which were then used to estimate the relative number of cavitation events per insonation (cavitation duty cycle) and the cavitation dose estimates of each nanoparticle concentration. Finally, the nanoparticle mixtures were exposed to low-duty cycle, histotripsy pulses. Passive cavitation detectors monitored cavitation emissions, which were used to estimate cavitation threshold pressures. RESULTS The nanoparticles reduced the MR signal of the coupling bath by 90% in T2- and T2*-weighted images and also removed almost all imaging artifacts caused by coupling bath motion. The coupling baths caused <5% changes in peak temperature change achieved during sonication, as observed via MR thermometry. At low duty cycle insonations, the nanoparticles decreased the cavitation threshold pressure by about 15 ± 7% in a manner uncorrelated with nanoparticle concentration. At high duty cycle insonations, the 0.5 cavitation duty cycle acoustic power threshold varied linearly with nanoparticle concentration. CONCLUSIONS Dilute aqueous magnetite nanoparticle suspensions effectively reduced MR imaging artifacts caused by the acoustic coupling bath. They also attenuated acoustic power deposition by <5%. For low duty cycle insonation regimes, the nanoparticles decreased the cavitation threshold by 15 ± 7%. However, for high-duty cycle regimes, the nanoparticles decreased the threshold for cavitation in proportion to nanoparticle concentration.
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Affiliation(s)
- Steven P Allen
- Department of Biomedical Engineering, University of Virginia, Charlottesville, VA, USA
| | - Tom Steeves
- Department of Mechanical Engineering, Virginia Tech, Blacksburg, VA, USA
| | - Austin Fergusson
- Graduate Program in Translational Biology, Medicine, and Health, Virginia Tech, Blacksburg, VA, USA
| | - Dave Moore
- The Focused Ultrasound Foundation, Charlottesville, VA, USA
| | - Richey M Davis
- Department of Chemical Engineering, Virginia Tech, Blacksburg, VA, USA
| | - Eli Vlaisialjevich
- Graduate Program in Translational Biology, Medicine, and Health, Virginia Tech, Blacksburg, VA, USA.,Department of Biomedical Engineering and Mechanics, Virginia Tech, Blacksburg, VA, USA
| | - Craig H Meyer
- Department of Biomedical Engineering, University of Virginia, Charlottesville, VA, USA.,Department of Radiology and Medical Imaging, University of Virginia, Charlottesville, VA, USA
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Aslani P, Drost L, Huang Y, Lucht BBC, Wong E, Czarnota G, Yee C, Wan BA, Ganesh V, Gunaseelan ST, David E, Chow E, Hynynen K. Thermal Therapy With a Fully Electronically Steerable HIFU Phased Array Using Ultrasound Guidance and Local Harmonic Motion Monitoring. IEEE Trans Biomed Eng 2019; 67:1854-1862. [PMID: 31647420 DOI: 10.1109/tbme.2019.2949478] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Abstract
The method of localized harmonic motion (LHM) monitoring has been proposed as an ultrasound-based monitoring technique for in vivo real-time ultrasound-guidance during thermal surgery. OBJECTIVE The focus of this paper is to study the performance of LHM monitoring in vivo in order to assess the tissue coagulation during ultrasound surgery of bone metastases. This is done through a pre-clinical study on large scale animals (pigs) as well as a first-in-human pilot study, using a hand held ultrasound-guided HIFU phased array. METHODS A flat, fully steerable HIFU phased array system (1024 elements, 100 mm diameter, 516 kHz), in combination with a co-aligned 64 element imaging system, is used to perform thermal surgery and monitor tissue coagulation using the LHM technique. The in vivo experiments are conducted using thirteen animals, followed by a first-in-human pilot study in which nine patients are enrolled. RESULTS The pre-clinical results show that the LHM monitoring method is able to detect about 80% of the observed coagulated tissue volumes visible in dissection. In the pilot study, six out of nine patients have durable pain reduction with good correlation observed from LHM detections. CONCLUSION In general, the results suggest that the LHM monitoring performance is promising in detecting thermal tissue coagulation during focused ultrasound surgery in tissues close to the bone. SIGNIFICANCE The LHM technique can offer a very accessible and cost-efficient monitoring solution during ultrasound surgery within a clinical setting.
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Ilyas A, Chen CJ, Ding D, Romeo A, Buell TJ, Wang TR, Kalani MYS, Park MS. Magnetic resonance-guided, high-intensity focused ultrasound sonolysis: potential applications for stroke. Neurosurg Focus 2019; 44:E12. [PMID: 29385918 DOI: 10.3171/2017.11.focus17608] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
Stroke is one of the leading causes of death worldwide and a significant source of long-term morbidity. Unfortunately, a substantial number of stroke patients either are ineligible or do not significantly benefit from contemporary medical and interventional therapies. To address this void, investigators recently made technological advances to render transcranial MR-guided, high-intensity focused ultrasound (MRg-HIFU) sonolysis a potential therapeutic option for both acute ischemic stroke (AIS)-as an alternative for patients with emergent large-vessel occlusion (ELVO) who are ineligible for endovascular mechanical thrombectomy (EMT) or as salvage therapy for patients in whom EMT fails-and intracerebral hemorrhage (ICH)-as a neoadjuvant means of clot lysis prior to surgical evacuation. Herein, the authors review the technological principles behind MRg-HIFU sonolysis, its results in in vitro and in vivo stroke models, and its potential clinical applications. As a noninvasive transcranial technique that affords rapid clot lysis, MRg-HIFU thrombolysis may develop into a therapeutic option for patients with AIS or ICH. However, additional studies of transcranial MRg-HIFU are necessary to ascertain the merit of this treatment approach for thrombolysis in both AIS and ICH, as well as its technical limitations and risks.
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Affiliation(s)
- Adeel Ilyas
- Department of Neurosurgery, University of Alabama at Birmingham, Alabama
| | - Ching-Jen Chen
- Department of Neurological Surgery, University of Virginia Health System, Charlottesville, Virginia; and
| | - Dale Ding
- Department of Neurosurgery, Barrow Neurological Institute, Phoenix, Arizona
| | - Andrew Romeo
- Department of Neurosurgery, University of Alabama at Birmingham, Alabama
| | - Thomas J Buell
- Department of Neurological Surgery, University of Virginia Health System, Charlottesville, Virginia; and
| | - Tony R Wang
- Department of Neurological Surgery, University of Virginia Health System, Charlottesville, Virginia; and
| | - M Yashar S Kalani
- Department of Neurological Surgery, University of Virginia Health System, Charlottesville, Virginia; and
| | - Min S Park
- Department of Neurological Surgery, University of Virginia Health System, Charlottesville, Virginia; and
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Rosnitskiy PB, Yuldashev PV, Sapozhnikov OA, Gavrilov LR, Khokhlova VA. Simulation of nonlinear trans-skull focusing and formation of shocks in brain using a fully populated ultrasound array with aberration correction. THE JOURNAL OF THE ACOUSTICAL SOCIETY OF AMERICA 2019; 146:1786. [PMID: 31590513 PMCID: PMC7064313 DOI: 10.1121/1.5126685] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/30/2019] [Revised: 07/23/2019] [Accepted: 08/28/2019] [Indexed: 05/21/2023]
Abstract
Multi-element high-intensity focused ultrasound phased arrays in the shape of hemispheres are currently used in clinics for thermal lesioning in deep brain structures. Certain side effects of overheating non-targeted tissues and skull bones have been revealed. Here, an approach is developed to mitigate these effects. A specific design of a fully populated 256-element 1-MHz array shaped as a spherical segment (F-number, F# = 1) and filled by randomly distributed equal-area polygonal elements is proposed. Capability of the array to generate high-amplitude shock fronts at the focus is tested in simulations by combining three numerical algorithms for linear and nonlinear field modeling and aberration correction. The algorithms are based on the combination of the Rayleigh integral, a linear pseudo-spectral time domain Kelvin-Voigt model, and nonlinear Westervelt model to account for the effects of inhomogeneities, aberrations, reflections, absorption, nonlinearity, and shear waves in the skull. It is shown that the proposed array can generate nonlinear waveforms with shock amplitudes >60 MPa at the focus deep inside the brain without exceeding the existing technical limitation on the intensity of 40 W/cm2 at the array elements. Such shock amplitudes are sufficient for mechanical ablation of brain tissues using the boiling histotripsy approach and implementation of other shock-based therapies.
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Affiliation(s)
- Pavel B Rosnitskiy
- Department of Acoustics, Physics Faculty, Moscow State University, Leninskie Gory, Moscow 119991, Russia
| | - Petr V Yuldashev
- Department of Acoustics, Physics Faculty, Moscow State University, Leninskie Gory, Moscow 119991, Russia
| | - Oleg A Sapozhnikov
- Department of Acoustics, Physics Faculty, Moscow State University, Leninskie Gory, Moscow 119991, Russia
| | - Leonid R Gavrilov
- Andreyev Acoustics Institute, Russian Federation, Moscow 117036, Russia
| | - Vera A Khokhlova
- Department of Acoustics, Physics Faculty, Moscow State University, Leninskie Gory, Moscow 119991, Russia
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50
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Knott EA, Swietlik JF, Longo KC, Watson RF, Green CM, Abel EJ, Lubner MG, Hinshaw JL, Smolock AR, Xu Z, Lee FT, Ziemlewicz TJ. Robotically-Assisted Sonic Therapy for Renal Ablation in a Live Porcine Model: Initial Preclinical Results. J Vasc Interv Radiol 2019; 30:1293-1302. [PMID: 31130365 PMCID: PMC6925588 DOI: 10.1016/j.jvir.2019.01.023] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2018] [Revised: 01/14/2019] [Accepted: 01/19/2019] [Indexed: 12/14/2022] Open
Abstract
PURPOSE To demonstrate the feasibility of Robotically Assisted Sonic Therapy (RAST)-a noninvasive and nonthermal focused ultrasound therapy based on histotripsy-for renal ablation in a live porcine model. MATERIALS AND METHODS RAST ablations (n = 11) were performed in 7 female swine: 3 evaluated at 1 week (acute) and 4 evaluated at 4 weeks (chronic). Treatment groups were acute bilateral (3 swine, 6 ablations with immediate computed tomography [CT] and sacrifice); chronic single kidney (3 swine, 3 ablations; CT at day 0, week 1, and week 4 after treatment, followed by sacrifice); and chronic bilateral (1 swine, 2 ablations). Treatments were performed using a prototype system (VortxRx; HistoSonics, Inc) and targeted a 2.5-cm-diameter sphere in the lower pole of each kidney, intentionally including the central collecting system. RESULTS Mean treatment time was 26.4 minutes. Ablations had a mean diameter of 2.4 ± 0.3 cm, volume of 8.5 ± 2.4 cm3, and sphericity index of 1.00. Median ablation volume decreased by 96.1% over 4 weeks. Histology demonstrated complete lysis with residual blood products inside the ablation zone. Temporary collecting system obstruction by thrombus was observed in 4/11 kidneys (2 acute and 2 chronic) and resolved by 1 week. There were no urinary leaks, main vessel thromboses, or adjacent organ injuries on imaging or necropsy. CONCLUSIONS In this normal porcine model, renal RAST demonstrated complete histologic destruction of the target renal tissue while sparing the urothelium.
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Affiliation(s)
- Emily A Knott
- Department of Radiology, University of Wisconsin, 600 Highland Ave., Madison, WI 53024.
| | - John F Swietlik
- Department of Radiology, University of Wisconsin, 600 Highland Ave., Madison, WI 53024
| | - Katherine C Longo
- Department of Radiology, University of Wisconsin, 600 Highland Ave., Madison, WI 53024
| | - Rao F Watson
- Department of Pathology, University of Wisconsin, 600 Highland Ave., Madison, WI 53024
| | - Chelsey M Green
- Department of Statistics, University of Wisconsin, 600 Highland Ave., Madison, WI 53024
| | - E Jason Abel
- Department of Radiology, University of Wisconsin, 600 Highland Ave., Madison, WI 53024; Department of Urology, University of Wisconsin, 600 Highland Ave., Madison, WI 53024
| | - Meghan G Lubner
- Department of Radiology, University of Wisconsin, 600 Highland Ave., Madison, WI 53024
| | - J Louis Hinshaw
- Department of Radiology, University of Wisconsin, 600 Highland Ave., Madison, WI 53024
| | - Amanda R Smolock
- Department of Radiology, Thomas Jefferson University, Philadelphia, Pennsylvania
| | - Zhen Xu
- Department of Biomedical Engineering, University of Michigan, Ann Arbor, Michigan
| | - Fred T Lee
- Department of Radiology, University of Wisconsin, 600 Highland Ave., Madison, WI 53024; Department of Urology, University of Wisconsin, 600 Highland Ave., Madison, WI 53024; Department of Biomedical Engineering, University of Wisconsin, 600 Highland Ave., Madison, WI 53024
| | - Timothy J Ziemlewicz
- Department of Radiology, University of Wisconsin, 600 Highland Ave., Madison, WI 53024
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