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Martin E, Aubry JF, Schafer M, Verhagen L, Treeby B, Pauly KB. ITRUSST consensus on standardised reporting for transcranial ultrasound stimulation. Brain Stimul 2024; 17:607-615. [PMID: 38670224 DOI: 10.1016/j.brs.2024.04.013] [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: 02/07/2024] [Revised: 03/30/2024] [Accepted: 04/18/2024] [Indexed: 04/28/2024] Open
Abstract
As transcranial ultrasound stimulation (TUS) advances as a precise, non-invasive neuromodulatory method, there is a need for consistent reporting standards to enable comparison and reproducibility across studies. To this end, the International Transcranial Ultrasonic Stimulation Safety and Standards Consortium (ITRUSST) formed a subcommittee of experts across several domains to review and suggest standardised reporting parameters for low intensity TUS, resulting in the guide presented here. The scope of the guide is limited to reporting the ultrasound aspects of a study. The guide and supplementary material provide a simple checklist covering the reporting of: (1) the transducer and drive system, (2) the drive system settings, (3) the free field acoustic parameters, (4) the pulse timing parameters, (5) in situ estimates of exposure parameters in the brain, and (6) intensity parameters. Detailed explanations for each of the parameters, including discussions on assumptions, measurements, and calculations, are also provided.
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Affiliation(s)
- Eleanor Martin
- Department of Medical Physics and Biomedical Engineering, University College London, London, UK; Wellcome/EPSRC Centre for Interventional and Surgical Sciences, University College London, London, UK
| | - Jean-François Aubry
- Physics for Medicine Paris, Inserm U1273, ESPCI Paris, CNRS UMR8063, PSL University, Paris, France
| | - Mark Schafer
- School of Biomedical Engineering, Science and Health Systems, Drexel University, Philadelphia, PA, USA
| | - Lennart Verhagen
- Donders Institute for Brain, Cognition and Behaviour, Radboud University, 6525 GD Nijmegen, The Netherlands
| | - Bradley Treeby
- Department of Medical Physics and Biomedical Engineering, University College London, London, UK
| | - Kim Butts Pauly
- Department of Radiology, Stanford University, Stanford, CA, USA.
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Martin E, Aubry JF, Schafer M, Verhagen L, Treeby B, Pauly KB. ITRUSST Consensus on Standardised Reporting for Transcranial Ultrasound Stimulation. ARXIV 2024:arXiv:2402.10027v1. [PMID: 38410648 PMCID: PMC10896372] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Subscribe] [Scholar Register] [Indexed: 02/28/2024]
Abstract
As transcranial ultrasound stimulation (TUS) advances as a precise, non-invasive neuromodulatory method, there is a need for consistent reporting standards to enable comparison and reproducibility across studies. To this end, the International Transcranial Ultrasonic Stimulation Safety and Standards Consortium (ITRUSST) formed a subcommittee of experts across several domains to review and suggest standardised reporting parameters for low intensity TUS, resulting in the guide presented here. The scope of the guide is limited to reporting the ultrasound aspects of a study. The guide and supplementary material provide a simple checklist covering the reporting of: (1) the transducer and drive system, (2) the drive system settings, (3) the free field acoustic parameters, (4) the pulse timing parameters, (5) in situ estimates of exposure parameters in the brain, and (6) intensity parameters. Detailed explanations for each of the parameters, including discussions on assumptions, measurements, and calculations, are also provided.
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Affiliation(s)
- Eleanor Martin
- Department of Medical Physics and Biomedical Engineering, University College London, London, U.K
- Wellcome/EPSRC Centre for Interventional and Surgical Sciences, University College London, London, UK
| | - Jean-François Aubry
- Physics for Medicine Paris, Inserm U1273, ESPCI Paris, CNRS UMR8063, PSL University, Paris, France
| | - Mark Schafer
- School of Biomedical Engineering, Science and Health Systems, Drexel University, Philadelphia, PA USA
| | - Lennart Verhagen
- Donders Institute for Brain, Cognition and Behaviour, Radboud University, 6525 GD Nijmegen, the Netherlands
| | - Bradley Treeby
- Department of Medical Physics and Biomedical Engineering, University College London, London, U.K
| | - Kim Butts Pauly
- Department of Radiology, Stanford University, Stanford, CA, USA
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Riis T, Feldman D, Losser A, Mickey B, Kubanek J. Device for Multifocal Delivery of Ultrasound Into Deep Brain Regions in Humans. IEEE Trans Biomed Eng 2024; 71:660-668. [PMID: 37695955 PMCID: PMC10803076 DOI: 10.1109/tbme.2023.3313987] [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] [Indexed: 09/13/2023]
Abstract
Low-intensity focused ultrasound provides the means to noninvasively stimulate or release drugs in specified deep brain targets. However, successful clinical translations require hardware that maximizes acoustic transmission through the skull, enables flexible electronic steering, and provides accurate and reproducible targeting while minimizing the use of MRI. We have developed a device that addresses these practical requirements. The device delivers ultrasound through the temporal and parietal skull windows, which minimize the attenuation and distortions of the ultrasound by the skull. The device consists of 252 independently controlled elements, which provides the ability to modulate multiple deep brain targets at a high spatiotemporal resolution, without the need to move the device or the subject. And finally, the device uses a mechanical registration method that enables accurate deep brain targeting both inside and outside of the MRI. Using this method, a single MRI scan is necessary for accurate targeting; repeated subsequent treatments can be performed reproducibly in an MRI-free manner. We validated these functions by transiently modulating specific deep brain regions in two patients with treatment-resistant depression.
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Manuel TJ, Sigona MK, Phipps MA, Kusunose J, Luo H, Yang PF, Newton AT, Gore JC, Grissom W, Chen LM, Caskey CF. Small volume blood-brain barrier opening in macaques with a 1 MHz ultrasound phased array. J Control Release 2023; 363:707-720. [PMID: 37827222 DOI: 10.1016/j.jconrel.2023.10.015] [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: 06/05/2023] [Revised: 10/05/2023] [Accepted: 10/08/2023] [Indexed: 10/14/2023]
Abstract
The use of focused ultrasound to open the blood-brain barrier (BBB) has the potential to deliver drugs to specific regions of the brain. The size of the BBB opening and ability to localize the opening determines the spatial extent and is a limiting factor in many applications of BBB opening where targeting a small brain region is desired. Here we evaluate the performance of a system designed for small opening volumes and highlight the unique challenges associated with pushing the spatial precision of this technique. To achieve small volume openings in cortical regions of the macaque brain, we tested a custom 1 MHz array transducer integrated into a magnetic resonance image-guided focused ultrasound system. Using real-time cavitation monitoring, we demonstrated twelve instances of single sonication, small volume BBB opening with average volumes of 59 ± 37 mm3 and 184 ± 2 mm3 in cortical and subcortical targets, respectively. We found high correlation between subject-specific acoustic simulations and observed openings when incorporating grey matter segmentation (R2 = 0.8577), and the threshold for BBB opening based on simulations was 0.53 MPa. Analysis of MRI-based safety assessment and cavitation signals indicate a safe pressure range for 1 MHz BBB opening and suggest that our system can be used to deliver drugs and gene therapy to small brain regions.
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Affiliation(s)
- Thomas J Manuel
- Vanderbilt University, Nashville, TN, USA; Vanderbilt University Institute of Imaging Science, Nashville, TN, USA
| | - Michelle K Sigona
- Vanderbilt University, Nashville, TN, USA; Vanderbilt University Institute of Imaging Science, Nashville, TN, USA
| | - M Anthony Phipps
- Vanderbilt University Medical Center, Nashville, TN, USA; Vanderbilt University Institute of Imaging Science, Nashville, TN, USA
| | - Jiro Kusunose
- Vanderbilt University Medical Center, Nashville, TN, USA; Vanderbilt University Institute of Imaging Science, Nashville, TN, USA
| | - Huiwen Luo
- Vanderbilt University, Nashville, TN, USA; Vanderbilt University Institute of Imaging Science, Nashville, TN, USA
| | - Pai-Feng Yang
- Vanderbilt University Medical Center, Nashville, TN, USA; Vanderbilt University Institute of Imaging Science, Nashville, TN, USA
| | - Allen T Newton
- Vanderbilt University Medical Center, Nashville, TN, USA; Vanderbilt University Institute of Imaging Science, Nashville, TN, USA
| | - John C Gore
- Vanderbilt University, Nashville, TN, USA; Vanderbilt University Medical Center, Nashville, TN, USA; Vanderbilt University Institute of Imaging Science, Nashville, TN, USA
| | - William Grissom
- Vanderbilt University, Nashville, TN, USA; Vanderbilt University Medical Center, Nashville, TN, USA; Vanderbilt University Institute of Imaging Science, Nashville, TN, USA
| | - Li Min Chen
- Vanderbilt University Medical Center, Nashville, TN, USA; Vanderbilt University Institute of Imaging Science, Nashville, TN, USA
| | - Charles F Caskey
- Vanderbilt University, Nashville, TN, USA; Vanderbilt University Medical Center, Nashville, TN, USA; Vanderbilt University Institute of Imaging Science, Nashville, TN, USA.
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Manuel TJ, Sigona MK, Phipps MA, Kusunose J, Luo H, Yang PF, Newton AT, Gore JC, Grissom W, Chen LM, Caskey CF. Small volume blood-brain barrier opening in macaques with a 1 MHz ultrasound phased array. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.03.02.530815. [PMID: 36909495 PMCID: PMC10002751 DOI: 10.1101/2023.03.02.530815] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 03/07/2023]
Abstract
Focused ultrasound blood-brain barrier (BBB) opening is a promising tool for targeted delivery of therapeutic agents into the brain. The volume of opening determines the extent of therapeutic administration and sets a lower bound on the size of targets which can be selectively treated. We tested a custom 1 MHz array transducer optimized for cortical regions in the macaque brain with the goal of achieving small volume openings. We integrated this device into a magnetic resonance image guided focused ultrasound system and demonstrated twelve instances of small volume BBB opening with average opening volumes of 59 ± 37 mm 3 and 184 ± 2 mm 3 in cortical and subcortical targets, respectively. We developed real-time cavitation monitoring using a passive cavitation detector embedded in the array and characterized its performance on a bench-top flow phantom mimicking transcranial BBB opening procedures. We monitored cavitation during in-vivo procedures and compared cavitation metrics against opening volumes and safety outcomes measured with FLAIR and susceptibility weighted MR imaging. Our findings show small BBB opening at cortical targets in macaques and characterize the safe pressure range for 1 MHz BBB opening. Additionally, we used subject-specific simulations to investigate variance in measured opening volumes and found high correlation (R 2 = 0.8577) between simulation predictions and observed measurements. Simulations suggest the threshold for 1 MHz BBB opening was 0.53 MPa. This system enables BBB opening for drug delivery and gene therapy to be targeted to more specific brain regions.
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