1
|
Natera-Villalba E, Ruiz-Yanzi MA, Gasca-Salas C, Matarazzo M, Martínez-Fernández R. MR-guided focused ultrasound in movement disorders and beyond: Lessons learned and new frontiers. Parkinsonism Relat Disord 2024; 122:106040. [PMID: 38378311 DOI: 10.1016/j.parkreldis.2024.106040] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/01/2024] [Accepted: 02/09/2024] [Indexed: 02/22/2024]
Abstract
The development of MR-guided focused ultrasound (MRgFUS) has provided a new therapeutic tool for neuropsychiatric disorders. In contrast to previously available neurosurgical techniques, MRgFUS allows precise impact on deep brain structures without the need for incision and yields an immediate effect. In its high-intensity modality (MRgHIFU), it produces accurate therapeutic thermoablation in previously selected brain targets. Importantly, the production of the lesion is progressive and highly controlled in real-time by both neuroimaging and clinical means. MRgHIFU ablation is already an accepted and widely used treatment for medically-refractory Parkinson's disease and essential tremor. Notably, other neurological disorders and diverse brain targets, including bilateral treatments, are currently under examination. Conversely, the low-intensity modality (MRgLIFU) shows promising prospects in neuromodulation and transient blood-brain barrier opening (BBBO). In the former circumstance, MRgLIFU could serve as a powerful clinical and research tool for non-invasively modulating brain activity and function. BBBO, on the other hand, emerges as a potentially impactful method to influence disease pathogenesis and progression by increasing brain target engagement of putative therapeutic agents. While promising, these applications remain experimental. As a recently developed technology, MRgFUS is not without challenges and questions to be addressed. Further developments and broader experience are necessary to enhance MRgFUS capabilities in both research and clinical practice, as well as to define device constraints. This clinical mini-review aims to provide an overview of the main evidence of MRgFUS application and to highlight unmet needs and future potentialities of the technique.
Collapse
Affiliation(s)
- Elena Natera-Villalba
- HM CINAC (Centro Integral de Neurociencias Abarca Campal), Hospital Universitario HM Puerta Del Sur, HM Hospitales, Madrid, Spain; PhD Medicine Program, Universidad Autónoma de Madrid, Madrid, Spain
| | - María-Agustina Ruiz-Yanzi
- HM CINAC (Centro Integral de Neurociencias Abarca Campal), Hospital Universitario HM Puerta Del Sur, HM Hospitales, Madrid, Spain
| | - Carmen Gasca-Salas
- HM CINAC (Centro Integral de Neurociencias Abarca Campal), Hospital Universitario HM Puerta Del Sur, HM Hospitales, Madrid, Spain; CIBERNED, Instituto Carlos III, Madrid, Spain; University CEU-San Pablo, Madrid, Spain
| | - Michele Matarazzo
- HM CINAC (Centro Integral de Neurociencias Abarca Campal), Hospital Universitario HM Puerta Del Sur, HM Hospitales, Madrid, Spain; CIBERNED, Instituto Carlos III, Madrid, Spain
| | - Raúl Martínez-Fernández
- HM CINAC (Centro Integral de Neurociencias Abarca Campal), Hospital Universitario HM Puerta Del Sur, HM Hospitales, Madrid, Spain; CIBERNED, Instituto Carlos III, Madrid, Spain; University CEU-San Pablo, Madrid, Spain.
| |
Collapse
|
2
|
Jameel A, Akgun S, Yousif N, Smith J, Jones B, Nandi D, Bain P, Gedroyc W. The evolution of ventral intermediate nucleus targeting in MRI-guided focused ultrasound thalamotomy for essential tremor: an international multi-center evaluation. Front Neurol 2024; 15:1345873. [PMID: 38595847 PMCID: PMC11002122 DOI: 10.3389/fneur.2024.1345873] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2023] [Accepted: 01/23/2024] [Indexed: 04/11/2024] Open
Abstract
Background The ventral intermediate nucleus (VIM) is the premiere target in magnetic resonance-guided focused ultrasound (MRgFUS) thalamotomy for tremor; however, there is no consensus on the optimal coordinates for ablation. This study aims to ascertain the various international VIM targeting approaches (VIM-TA) and any evolution in practice. Methods International MRgFUS centers were invited to share VIM-TAs in 2019 and 2021. Analyses of any modification in practice and of anatomical markers and/or tractography in use were carried out. Each VIM-TA was mapped in relation to the mid-commissural point onto a 3D thalamic nucleus model created from the Schaltenbrand-Wahren atlas. Results Of the 39 centers invited, 30 participated across the study period, providing VIM-TAs from 26 centers in 2019 and 23 in 2021. The results are reported as percentages of the number of participating centers in that year. In 2019 and 2021, respectively, 96.2% (n = 25) and 95.7% (n = 22) of centers based their targeting on anatomical landmarks rather than tractography. Increased adoption of tractography in clinical practice and/or for research was noted, changing from 34.6% to 78.3%. There was a statistically significant change in VIM-TAs in the superior-inferior plane across the study period; the percentage of VIM-TAs positioned 2 mm above the intercommissural line (ICL) increased from 16.0% in 2019 to 40.9% in 2021 (WRST, p < 0.05). This position is mapped at the center of VIM on the 3D thalamic model created based on the Schaltenbrand-Wahren atlas. In contrast, the VIM-TA medial-lateral and anterior-posterior positions remained stable. In 2022, 63.3% of participating centers provided the rationale for their VIM-TAs and key demographics. The centers were more likely to target 2 mm above the ICL if they had increased experience (more than 100 treatments) and/or if they were North American. Conclusion Across the study period, FUS centers have evolved their VIM targeting superiorly to target the center of the VIM (2 mm above the ICL) and increased the adoption of tractography to aid VIM localization. This phenomenon is observed across autonomous international centers, suggesting that it is a more optimal site for FUS thalamotomy in tremors.
Collapse
Affiliation(s)
- Ayesha Jameel
- Imperial College London, London, United Kingdom
- Imperial College Healthcare NHS Trust, London, United Kingdom
| | - Sena Akgun
- Sapienza University of Rome, Rome, Italy
| | - Nada Yousif
- University of Hertfordshire, Hatfield, United Kingdom
| | - Joely Smith
- Imperial College London, London, United Kingdom
| | - Brynmor Jones
- Imperial College Healthcare NHS Trust, London, United Kingdom
| | - Dipankar Nandi
- Imperial College Healthcare NHS Trust, London, United Kingdom
| | - Peter Bain
- Imperial College London, London, United Kingdom
| | | |
Collapse
|
3
|
Kim C, Eames M, Paeng DG. Improving Sonication Efficiency in Transcranial MR-Guided Focused Ultrasound Treatment: A Patient-Data Simulation Study. Bioengineering (Basel) 2023; 11:27. [PMID: 38247904 PMCID: PMC10813010 DOI: 10.3390/bioengineering11010027] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2023] [Revised: 12/13/2023] [Accepted: 12/22/2023] [Indexed: 01/23/2024] Open
Abstract
The potential improvement in sonication efficiency achieved by tilting the focused ultrasound (FUS) transducer of the transcranial MR-guided FUS system is presented. A total of 56 cases of patient treatment data were used. The relative position of the clinical FUS transducer to the patient's head was reconstructed, and region-specific skull density and porosity were calculated based on the patient's CT volume image. The total transmission coefficient of acoustic waves emitted from each channel was calculated. Then, the total energy penetrating the human skull-which represents the sonication efficiency-was estimated. As a result, improved sonication efficiency was by titling the FUS transducer to a more appropriate angle achieved in all 56 treatment cases. This simulation result suggests the potential improvement in transcranial-focused ultrasound treatment by simply adjusting the transducer angle.
Collapse
Affiliation(s)
- Changsoo Kim
- Research Institute for Basic Sciences, Jeju National University, Jeju 63243, Republic of Korea;
| | - Matthew Eames
- Focused Ultrasound Foundation, Charlottesville, VA 22903, USA;
- Department of Radiology, University of Virginia, Charlottesville, VA 22903, USA
| | - Dong-Guk Paeng
- Focused Ultrasound Foundation, Charlottesville, VA 22903, USA;
- Ocean System Engineering, Jeju National University, Jeju 63243, Republic of Korea
| |
Collapse
|
4
|
Xu P, Wu N, Shen G. A rapid element pressure field simulation method for transcranial phase correction in focused ultrasound therapy. Phys Med Biol 2023; 68:235015. [PMID: 37934058 DOI: 10.1088/1361-6560/ad0a59] [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: 08/03/2023] [Accepted: 11/07/2023] [Indexed: 11/08/2023]
Abstract
Transcranial focused ultrasound ablation has emerged as a promising technique for treating neurological disorders. The clinical system exclusively employed the ray tracing method to compute phase aberrations induced by the human skull, taking into account computational time constraints. However, this method compromises slightly on accuracy compared to simulation-based methods. This study evaluates a fast simulation method that simulates the time-harmonic pressure field within the region of interest for effective phase correction. Experimental validation was carried out using a 512-element, 670 kHz hemispherical transducer for fourex vivoskulls. The ray tracing method achieved a restoration ratio of 64.81% ± 4.33% of acoustic intensity normalized to hydrophone measurements. In comparison, the rapid simulation method demonstrated improved results with a restoration ratio of 73.10% ± 7.46%, albeit slightly lower than the full-wave simulation which achieved a restoration ratio of 75.87% ± 5.40%. The rapid simulation methods exhibited computational times that were less than five minutes for parallel computation with 8 threads. The incident angle was calculated, and a maximum difference of 6.8 degrees was found when the fixed position of the skull was changed. Meanwhile, the restoration ratio of acoustic intensity was validated to be above 70% for different target positions away from the geometrical focus of the transducer. The favorable balance between time consumption and correction accuracy makes this method valuable for clinical treatment applications.
Collapse
Affiliation(s)
- Peng Xu
- School of Biomedical Engineering, Shanghai Jiao Tong University, Shanghai, People's Republic of China
| | - Nan Wu
- Shanghai Shende Green Medical Era Healthcare Technology Co., Ltd., Shanghai, People's Republic of China
| | - Guofeng Shen
- School of Biomedical Engineering, Shanghai Jiao Tong University, Shanghai, People's Republic of China
| |
Collapse
|
5
|
Kyle K, Maller J, Barnett Y, Jonker B, Barnett M, D’Souza A, Calamante F, Maamary J, Peters J, Wang C, Tisch S. Tremor suppression following treatment with MRgFUS: skull density ratio consistency and degree of posterior dentatorubrothalamic tract lesioning predicts long-term clinical outcomes in essential tremor. Front Neurol 2023; 14:1129430. [PMID: 37181561 PMCID: PMC10166854 DOI: 10.3389/fneur.2023.1129430] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2022] [Accepted: 03/27/2023] [Indexed: 05/16/2023] Open
Abstract
Objectives Magnetic resonance-guided focussed ultrasound (MRgFUS) is an incisionless ablative procedure, widely used for treatment of Parkinsonian and Essential Tremor (ET). Enhanced understanding of the patient- and treatment-specific factors that influence sustained long-term tremor suppression could help clinicians achieve superior outcomes via improved patient screening and treatment strategy. Methods We retrospectively analysed data from 31 subjects with ET, treated with MRgFUS at a single centre. Tremor severity was assessed with parts A, B and C of the Clinical Rating Scale for Tremor (CRST) as well as the combined CRST. Tremor in the dominant and non-dominant hand was assessed with Hand Tremor Scores (HTS), derived from the CRST. Pre- and post-treatment imaging data were analysed to determine ablation volume overlap with automated thalamic segmentations, and the dentatorubrothalamic tract (DRTT) and compared with percentage change in CRST and HTS following treatment. Results Tremor symptoms were significantly reduced following treatment. Combined pre-treatment CRST (mean: 60.7 ± 17.3) and HTS (mean: 19.2 ± 5.7) improved by an average of 45.5 and 62.6%, respectively. Percentage change in CRST was found to be significantly negatively associated with age (β = -0.375, p = 0.015), and SDR standard deviation (SDRSD; β = -0.324, p = 0.006), and positively associated with ablation overlap with the posterior DRTT (β = 0.535, p < 0.001). Percentage HTS improvement in the dominant hand decreased significantly with older age (β = -0.576, p < 0.01). Conclusion Our results suggest that increased lesioning of the posterior region of the DRTT could result in greater improvements in combined CRST and non-dominant hand HTS, and that subjects with lower SDR standard deviation tended to experience greater improvement in combined CRST.
Collapse
Affiliation(s)
- Kain Kyle
- Brain and Mind Centre, The University of Sydney, Sydney, NSW, Australia
- Sydney Neuroimaging Analysis Centre, Camperdown, NSW, Australia
| | | | - Yael Barnett
- Department of Medical Imaging, and Neurology, St Vincent’s Hospital, Darlinghurst, NSW, Australia
- Department of Neurology, St Vincent’s Hospital, Darlinghurst, NSW, Australia
| | - Benjamin Jonker
- Department of Neurosurgery, St Vincent’s Hospital, Darlinghurst, NSW, Australia
- Royal Prince Alfred Institute of Academic Surgery, University of Sydney, Camperdown, NSW, Australia
| | - Michael Barnett
- Brain and Mind Centre, The University of Sydney, Sydney, NSW, Australia
- Sydney Neuroimaging Analysis Centre, Camperdown, NSW, Australia
- Department of Neurology, Royal Prince Alfred Hospital, Camperdown, NSW, Australia
| | - Arkiev D’Souza
- Brain and Mind Centre, The University of Sydney, Sydney, NSW, Australia
| | - Fernando Calamante
- Brain and Mind Centre, The University of Sydney, Sydney, NSW, Australia
- School of Biomedical Engineering, The University of Sydney, Sydney, NSW, Australia
- Sydney Imaging, The University of Sydney, Sydney, NSW, Australia
| | - Joel Maamary
- Department of Neurology, St Vincent’s Hospital, Darlinghurst, NSW, Australia
- School of Medicine, University of New South Wales, Sydney, NSW, Australia
| | - James Peters
- Department of Neurology, St Vincent’s Hospital, Darlinghurst, NSW, Australia
| | - Chenyu Wang
- Brain and Mind Centre, The University of Sydney, Sydney, NSW, Australia
- Sydney Neuroimaging Analysis Centre, Camperdown, NSW, Australia
| | - Stephen Tisch
- Department of Neurology, St Vincent’s Hospital, Darlinghurst, NSW, Australia
- School of Medicine, University of New South Wales, Sydney, NSW, Australia
| |
Collapse
|
6
|
Jing B, Strassle Rojas S, Lindsey BD. Effect of skull porosity on ultrasound transmission and wave mode conversion at large incidence angles. Med Phys 2023; 50:3092-3102. [PMID: 36810723 DOI: 10.1002/mp.16318] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2022] [Revised: 01/19/2023] [Accepted: 02/06/2023] [Indexed: 02/24/2023] Open
Abstract
BACKGROUND Transcranial ultrasound imaging and therapy depend on the efficient transmission of acoustic energy through the skull. Multiple previous studies have concluded that a large incidence angle should be avoided during transcranial-focused ultrasound therapy to ensure transmission through the skull. Alternatively, some other studies have shown that longitudinal-to-shear wave mode conversion might improve transmission through the skull when the incidence angle is increased above the critical angle (i.e., 25° to 30°). PURPOSE The effect of skull porosity on the transmission of ultrasound through the skull at varying incidence angles was investigated for the first time to elucidate why transmission through the skull at large angles of incidence is decreased in some cases but improved in other cases. METHODS Transcranial ultrasound transmission at varying incidence angles (0°-50°) was investigated in phantoms and ex vivo skull samples with varying bone porosity (0% to 28.54% ± 3.36%) using both numerical and experimental methods. First, the elastic acoustic wave transmission through the skull was simulated using micro-computed tomography data of ex vivo skull samples. The trans-skull pressure was compared between skull segments having three levels of porosity, that is, low porosity (2.65% ± 0.03%), medium porosity (13.41% ± 0.12%), and high porosity (26.9%). Next, transmission through two 3D-printed resin skull phantoms (compact vs. porous phantoms) was experimentally measured to test the effect of porous microstructure alone on ultrasound transmission through flat plates. Finally, the effect of skull porosity on ultrasound transmission was investigated experimentally by comparing transmission through two ex vivo human skull segments having similar thicknesses but different porosities (13.78% ± 2.05% vs. 28.54% ± 3.36%). RESULTS Numerical simulations indicated that an increase in transmission pressure occurs at large incidence angles for skull segments having low porosities but not for those with high porosity. In experimental studies, a similar phenomenon was observed. Specifically, for the low porosity skull sample (13.78% ± 2.05%), the normalized pressure was 0.25 when the incidence angle increased to 35°. However, for the high porosity sample (28.54% ± 3.36%), the pressure was no more than 0.1 at large incidence angles. CONCLUSIONS These results indicate that the skull porosity has an evident effect on the transmission of ultrasound at large incidence angles. The wave mode conversion at large, oblique incidence angles could enhance the transmission of ultrasound through parts of the skull having lower porosity in the trabecular layer. However, for transcranial ultrasound therapy in the presence of highly porous trabecular bone, transmission at a normal incidence angle is preferable relative to oblique incidence angles due to the higher transmission efficiency.
Collapse
Affiliation(s)
- Bowen Jing
- Wallace H Coulter Department of Biomedical Engineering, Georgia Institute of Technology and Emory University, Atlanta, Georgia, USA
| | - Stephan Strassle Rojas
- School of Electrical and Computer Engineering, Georgia Institute of Technology, Atlanta, Georgia, USA
| | - Brooks D Lindsey
- Wallace H Coulter Department of Biomedical Engineering, Georgia Institute of Technology and Emory University, Atlanta, Georgia, USA.,School of Electrical and Computer Engineering, Georgia Institute of Technology, Atlanta, Georgia, USA
| |
Collapse
|
7
|
Baek H, Lockwood D, Mason EJ, Obusez E, Poturalski M, Rammo R, Nagel SJ, Jones SE. Clinical Intervention Using Focused Ultrasound (FUS) Stimulation of the Brain in Diverse Neurological Disorders. Front Neurol 2022; 13:880814. [PMID: 35614924 PMCID: PMC9124976 DOI: 10.3389/fneur.2022.880814] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2022] [Accepted: 04/07/2022] [Indexed: 12/02/2022] Open
Abstract
Various surgical techniques and pharmaceutical treatments have been developed to improve the current technologies of treating brain diseases. Focused ultrasound (FUS) is a new brain stimulation modality that can exert a therapeutic effect on diseased brain cells, with this effect ranging from permanent ablation of the pathological neural circuit to transient excitatory/inhibitory modulation of the neural activity depending on the acoustic energy of choice. With the development of intraoperative imaging technology, FUS has become a clinically available noninvasive neurosurgical option with visual feedback. Over the past 10 years, FUS has shown enormous potential. It can deliver acoustic energy through the physical barrier of the brain and eliminate abnormal brain cells to treat patients with Parkinson's disease and essential tremor. In addition, FUS can help introduce potentially beneficial therapeutics at the exact brain region where they need to be, bypassing the brain's function barrier, which can be applied for a wide range of central nervous system disorders. In this review, we introduce the current FDA-approved clinical applications of FUS, ranging from thermal ablation to blood barrier opening, as well as the emerging applications of FUS in the context of pain control, epilepsy, and neuromodulation. We also discuss the expansion of future applications and challenges. Broadening FUS technologies requires a deep understanding of the effect of ultrasound when targeting various brain structures in diverse disease conditions in the context of skull interface, anatomical structure inside the brain, and pathology.
Collapse
Affiliation(s)
- Hongchae Baek
- Cleveland Clinic, Imaging Institute, Cleveland, OH, United States
- Center for Neurological Restoration, Cleveland Clinic, Neurological Institute, Cleveland, OH, United States
| | - Daniel Lockwood
- Cleveland Clinic, Imaging Institute, Cleveland, OH, United States
| | | | - Emmanuel Obusez
- Cleveland Clinic, Imaging Institute, Cleveland, OH, United States
| | | | - Richard Rammo
- Center for Neurological Restoration, Cleveland Clinic, Neurological Institute, Cleveland, OH, United States
| | - Sean J. Nagel
- Center for Neurological Restoration, Cleveland Clinic, Neurological Institute, Cleveland, OH, United States
| | - Stephen E. Jones
- Cleveland Clinic, Imaging Institute, Cleveland, OH, United States
- *Correspondence: Stephen E. Jones
| |
Collapse
|
8
|
Torii J, Maesawa S, Nakatsubo D, Tsugawa T, Kato S, Ishizaki T, Takai S, Shibata M, Wakabayashi T, Tsuboi T, Suzuki M, Saito R. Cutoff values for the best management strategy for magnetic resonance-guided focused ultrasound ablation for essential tremor. J Neurosurg 2022; 138:38-49. [PMID: 35993838 DOI: 10.3171/2022.3.jns212460] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
OBJECTIVE The efficacy of magnetic resonance-guided focused ultrasound (MRgFUS) ablation for essential tremor (ET) is well known; however, no prognostic factors have been established. The authors aimed to retrospectively investigate MRgFUS ablation outcomes and associated factors and to define the cutoff values for each prognostic factor. METHODS Sixty-four Japanese patients who underwent unilateral ventral intermediate nucleus thalamotomy with MRgFUS for ET were included. Follow-up evaluations were performed at 1 week and 1, 3, 6, 12, and 24 months postoperatively. Tremor suppression was evaluated using the Clinical Rating Scale for Tremor (CRST), and adverse effects were recorded postoperatively. Outcome-associated factors were examined preoperatively, intraoperatively, and postoperatively using multivariate analyses. The cutoff values for the prognostic factors were calculated using receiver operating characteristics. RESULTS Percentage improvements in the CRST scores of the affected upper limb were 82.4%, 72.2%, 68.6%, and 65.9% at 1, 3, 6, and 12 months, respectively. Preoperatively, a high skull density ratio (SDR) (p ≤ 0.047), low CRST part B score (used to assess tremors during several tasks) (cutoff value 25, p ≤ 0.041), and nonoccurrence of resting tremors (p = 0.027) were significantly associated with improved tremor control. An intraoperatively high maximum mean temperature (cutoff value 52.5°C, p ≤ 0.047), postoperatively large lesion (cutoff value 3.9 mm in the anterior-posterior direction, p ≤ 0.002; cutoff value 5.0-5.55 mm in the superior-inferior direction, p ≤ 0.026), and small transducer focus correction (p ≤ 0.015) were also associated with improved tremor control. No valid cutoff value was found for SDR. Adverse effects (limb weakness, sensory disturbance, ataxia/walking disturbance, dysgeusia, dysarthria, and facial swelling) occurred transiently and were associated with high SDR, high temperature, high number of sonication sessions, large lesion, and occurrence of resting tremor. Patients who developed leg weakness experienced greater percentage improvement in tremors at 3 months postoperatively than those who did not. CONCLUSIONS MRgFUS ablation could be used to achieve good tremor control with acceptable adverse effects in Japanese patients with ET. The relatively low SDR in Asian ethnic groups as compared with that of Western populations makes treatment difficult; however, the cutoff values obtained in this study may be useful for achieving good treatment outcomes even in such patients. Clinical trial registration no.: UMIN000026952 (University Hospital Medical Information Network). ABBREVIATIONS ACPC = anterior commissure-posterior commissure; AP = anterior to posterior; CRST = Clinical Rating Scale for Tremor; ET = essential tremor; MRgFUS = magnetic resonance-guided focused ultrasound; PC = posterior commissure; PSA = posterior subthalamic area; RL = right to left; ROC = receiver operating characteristic; SDR = skull density ratio; SI = superior to inferior; T2WI = T2-weighted imaging; VIM = ventral intermediate nucleus.
Collapse
Affiliation(s)
- Jun Torii
- Department of Neurosurgery, Nagoya University Graduate School of Medicine
| | - Satoshi Maesawa
- Department of Neurosurgery, Nagoya University Graduate School of Medicine
| | - Daisuke Nakatsubo
- Department of Neurosurgery, Nagoya University Graduate School of Medicine
- Focused Ultrasound Therapy Center, Nagoya Kyoritsu Hospital
| | - Takahiko Tsugawa
- Focused Ultrasound Therapy Center, Nagoya Kyoritsu Hospital
- Nagoya Radiosurgery Center, Nagoya Kyoritsu Hospita
| | - Sachiko Kato
- Focused Ultrasound Therapy Center, Nagoya Kyoritsu Hospital
- Nagoya Radiosurgery Center, Nagoya Kyoritsu Hospita
| | | | - Sou Takai
- Department of Neurosurgery, Ichinomiya Municipal Hospital
| | - Masashi Shibata
- Focused Ultrasound Therapy Center, Nagoya Kyoritsu Hospital
- Nagoya Radiosurgery Center, Nagoya Kyoritsu Hospita
| | | | - Takashi Tsuboi
- Department of Neurology, Nagoya University Graduate School of Medicine, Aichi, Japan
| | - Masashi Suzuki
- Department of Neurology, Nagoya University Graduate School of Medicine, Aichi, Japan
| | - Ryuta Saito
- Department of Neurosurgery, Nagoya University Graduate School of Medicine
| |
Collapse
|
9
|
Darmani G, Bergmann T, Butts Pauly K, Caskey C, de Lecea L, Fomenko A, Fouragnan E, Legon W, Murphy K, Nandi T, Phipps M, Pinton G, Ramezanpour H, Sallet J, Yaakub S, Yoo S, Chen R. Non-invasive transcranial ultrasound stimulation for neuromodulation. Clin Neurophysiol 2022; 135:51-73. [DOI: 10.1016/j.clinph.2021.12.010] [Citation(s) in RCA: 17] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2021] [Revised: 12/20/2021] [Accepted: 12/22/2021] [Indexed: 12/13/2022]
|
10
|
Kang KC, Kim YH, Kim JN, Kabir M, Zhang Y, Ghanouni P, Park KK, Firouzi K, Khuri-Yakub BT. Increasing the transmission efficiency of transcranial ultrasound using a dual-mode conversion technique based on Lamb waves. THE JOURNAL OF THE ACOUSTICAL SOCIETY OF AMERICA 2022; 151:2159. [PMID: 35364946 PMCID: PMC8957390 DOI: 10.1121/10.0009849] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/14/2021] [Revised: 02/24/2022] [Accepted: 03/05/2022] [Indexed: 06/14/2023]
Abstract
Transcranial focused ultrasound (FUS) is a noninvasive treatment for brain tumors and neuromodulation. Based on normal incidence, conventional FUS techniques use a focused or an array of ultrasonic transducers to overcome the attenuation and absorption of ultrasound in the skull; however, this remains the main limitation of using FUS. A dual-mode conversion technique based on Lamb waves is proposed to achieve high transmission efficiency. This concept was validated using the finite element analysis (FEA) and experiments based on changes in the incident angle. Aluminum, plexiglass, and a human skull were used as materials with different attenuations. The transmission loss was calculated for each material, and the results were compared with the reflectance function of the Lamb waves. Oblique incidence based on dual-mode conversion exhibited a better transmission efficiency than that of a normal incidence for all of the specimens. The total transmission losses for the materials were 13.7, 15.46, and 3.91 dB less than those associated with the normal incidence. A wedge transducer was designed and fabricated to implement the proposed method. The results demonstrated the potential applicability of the dual-mode conversion technique for the human skull.
Collapse
Affiliation(s)
- Ki Chang Kang
- Mechanical Convergence Engineering, Hanyang University, Seoul, Republic of Korea
| | - Young Hun Kim
- Mechanical Convergence Engineering, Hanyang University, Seoul, Republic of Korea
| | - Jeong Nyeon Kim
- E. L. Ginzton Laboratory, Department of Electrical Engineering, Stanford University, Stanford, California 94305, USA
| | - Minoo Kabir
- E. L. Ginzton Laboratory, Department of Electrical Engineering, Stanford University, Stanford, California 94305, USA
| | - Yichi Zhang
- E. L. Ginzton Laboratory, Department of Electrical Engineering, Stanford University, Stanford, California 94305, USA
| | - Pejman Ghanouni
- Department of Radiology, Stanford University, Stanford, California 94305, USA
| | - Kwan Kyu Park
- Mechanical Convergence Engineering, Hanyang University, Seoul, Republic of Korea
| | - Kamyar Firouzi
- E. L. Ginzton Laboratory, Department of Electrical Engineering, Stanford University, Stanford, California 94305, USA
| | - Burtus T Khuri-Yakub
- E. L. Ginzton Laboratory, Department of Electrical Engineering, Stanford University, Stanford, California 94305, USA
| |
Collapse
|
11
|
Seo H, Huh H, Lee EH, Park J. Numerical Evaluation of the Effects of Transducer Displacement on Transcranial Focused Ultrasound in the Rat Brain. Brain Sci 2022; 12:216. [PMID: 35203979 PMCID: PMC8870101 DOI: 10.3390/brainsci12020216] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2021] [Revised: 01/15/2022] [Accepted: 02/03/2022] [Indexed: 02/04/2023] Open
Abstract
Focused ultrasound is a promising therapeutic technique, as it involves the focusing of an ultrasonic beam with sufficient acoustic energy into a target brain region with high precision. Low-intensity ultrasound transmission by a single-element transducer is mostly established for neuromodulation applications and blood-brain barrier disruption for drug delivery. However, transducer positioning errors can occur without fine control over the sonication, which can affect repeatability and lead to reliability problems. The objective of this study was to determine whether the target brain region would be stable under small displacement (0.5 mm) of the transducer based on numerical simulations. Computed-tomography-derived three-dimensional models of a rat head were constructed to investigate the effects of transducer displacement in the caudate putamen (CP) and thalamus (TH). Using three different frequencies (1.1, 0.69, and 0.25 MHz), the transducer was displaced by 0.5 mm in each of the following six directions: superior, interior, anterior, posterior, left, and right. The maximum value of the intracranial pressure field was calculated, and the targeting errors were determined by the full-width-at-half-maximum (FWHM) overlap between the free water space (FWHMwater) and transcranial transmission (FWHMbase). When the transducer was positioned directly above the target region, a clear distinction between the target regions was observed, resulting in 88.3%, 81.5%, and 84.5% FWHMwater for the CP and 65.6%, 76.3%, and 64.4% FWHMwater for the TH at 1.1, 0.69, and 0.25 MHz, respectively. Small transducer displacements induced both enhancement and reduction of the peak pressure and targeting errors, compared with when the transducer was displaced in water. Small transducer displacement to the left resulted in the lowest stability, with 34.8% and 55.0% targeting accuracy (FWHMwater) at 1.1 and 0.69 MHz in the TH, respectively. In addition, the maximum pressure was reduced by up to 11% by the transducer displacement. This work provides the targeting errors induced by transducer displacements through a preclinical study and recommends that attention be paid to determining the initial sonication foci in the transverse plane in the cases of small animals.
Collapse
Affiliation(s)
- Hyeon Seo
- Medical Device Development Center, Daegu-Gyeongbuk Medical Innovation Foundation, Daegu 41061, Korea; (H.S.); (H.H.); (E.-H.L.)
| | - Hyungkyu Huh
- Medical Device Development Center, Daegu-Gyeongbuk Medical Innovation Foundation, Daegu 41061, Korea; (H.S.); (H.H.); (E.-H.L.)
| | - Eun-Hee Lee
- Medical Device Development Center, Daegu-Gyeongbuk Medical Innovation Foundation, Daegu 41061, Korea; (H.S.); (H.H.); (E.-H.L.)
| | - Juyoung Park
- Medical Device Development Center, Daegu-Gyeongbuk Medical Innovation Foundation, Daegu 41061, Korea; (H.S.); (H.H.); (E.-H.L.)
- Department of High-Tech Medical Device, College of Future Industry, Gachon University, Seongnam-si 13120, Korea
| |
Collapse
|
12
|
Wathen C, Yang AI, Hitti FL, Henry L, Chaibainou H, Baltuch GH. Feasibility of Magnetic Resonance-Guided Focused Ultrasound Thalamotomy for Essential Tremor in the Setting of Prior Craniotomy. Oper Neurosurg (Hagerstown) 2022; 22:61-65. [PMID: 35007218 DOI: 10.1227/ons.0000000000000012] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2021] [Accepted: 08/24/2021] [Indexed: 11/19/2022] Open
Abstract
BACKGROUND Magnetic resonance imaging-guided focused ultrasound (MRgFUS) thalamotomy is a rapidly evolving therapy for the treatment of essential tremor. Although the skull is a major determinant of the delivery of acoustic energy to the target, how the presence of a prior craniotomy must be accounted for during lesioning is unclear. OBJECTIVE To demonstrate novel application of this therapeutic option in a patient with a history of prior craniotomies for unrelated intracranial pathologies. METHODS A 55-yr-old man with a history of right frontal craniotomy for resection of a colloid cyst underwent a left ventrointermedius nucleus thalamotomy through MRgFUS. The prior craniotomy flap was not excluded in the treatment plan; however, all bony defects and hardware were marked as "no-pass" regions. Clinical outcomes were collected at the 6-mo follow-up. RESULTS Transducer elements whose acoustic paths would have been altered by the craniotomy defect were turned off. Sonications reaching lesional temperatures of up to 56°C were successfully delivered. The procedure was well-tolerated, without any persistent intra-ablation or postablation adverse effects. The presence of a lesion was confirmed on MRI, which was associated with a significant reduction in the patient's tremor that was sustained at the 6-mo follow-up. CONCLUSION This case demonstrates the safety and efficacy of MRgFUS thalamotomy in a patient with prior craniotomies and highlights our strategy for acoustic lesioning in this setting.
Collapse
Affiliation(s)
- Connor Wathen
- Department of Neurosurgery, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, USA
| | - Andrew I Yang
- Department of Neurosurgery, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, USA
| | - Frederick L Hitti
- Department of Neurosurgery, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, USA
| | | | - Hanane Chaibainou
- Department of Neurosurgery, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, USA
| | - Gordon H Baltuch
- Department of Neurosurgery, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, USA
| |
Collapse
|
13
|
Ahmed AK, Guo S, Kelm N, Clanton R, Melhem ER, Gullapalli RP, Ksendzovsky A, Eisenberg HM, Miller TR, Gandhi D. Technical Comparison of Treatment Efficiency of Magnetic Resonance-Guided Focused Ultrasound Thalamotomy and Pallidotomy in Skull Density Ratio-Matched Patient Cohorts. Front Neurol 2022; 12:808810. [PMID: 35126300 PMCID: PMC8813961 DOI: 10.3389/fneur.2021.808810] [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: 11/04/2021] [Accepted: 12/17/2021] [Indexed: 11/24/2022] Open
Abstract
Objective MR-guided focused ultrasound (MRgFUS) is increasingly being used to treat patients with essential tremor (ET) and Parkinson's disease (PD) with thalamotomy and pallidotomy, respectively. Pallidotomy is performed off-center within the cranium compared to thalamotomy and may present challenges to therapeutic lesioning due to this location. However, the impact of target location on treatment efficiency and ability to create therapeutic lesions has not been studied. This study aimed to compare the physical efficiency of MRgFUS thalamotomy and pallidotomy. Methods Treatment characteristics were compared between patients treated with thalamotomy (n = 20) or pallidotomy (n = 20), matched by skull density ratios (SDR). Aspects of treatment efficiency were compared between these groups. Demographic and comparative statistics were conducted to assess these differences. Acoustic field simulations were performed to compare and validate the simulated temperature profile for VIM and GPi ablation. Results Lower SDR values were associated with greater energy requirement for thalamotomy (R2 = 0.197, p = 0.049) and pallidotomy (R2 = 0.342, p = 0.007). The impact of low SDR on efficiency reduction was greater for pallidotomy, approaching significance (p = 0.061). A nearly two-fold increase in energy was needed to reach 50°C in pallidotomy (10.9kJ) than in thalamotomy (5.7kJ), (p = 0.002). Despite lower energy requirement, the maximum average temperature reached was higher in thalamotomy (56.7°C) than in pallidotomy (55.0°C), (p = 0.017). Mean incident angle of acoustic beams was lesser in thalamotomy (12.7°) than in pallidotomy (18.6°), (p < 0.001). For all patients, a lesser mean incident angle correlated with a higher maximum average temperature reached (R2 = 0.124, p = 0.026), and less energy needed to reach 50°C (R2=0.134, p = 0.020). Greater skull thickness was associated with a higher maximum energy for a single sonication for thalamotomy (R2 = 0.206, p = 0.045) and pallidotomy (R2 = 0.403, p = 0.003). An acoustic and temperature field simulation validated similar findings for thalamotomy and pallidotomy in a single patient. Conclusion The centrally located VIM offers a more efficient location for therapeutic lesioning compared to GPi pallidotomy in SDR matched cohort of patients. The impact on therapeutic lesioning with lower SDR may be greater for pallidotomy patients. As newer off-center targets are investigated, these findings can inform patient selection and treatment requirements for lesion production.
Collapse
Affiliation(s)
- Abdul-Kareem Ahmed
- Department of Neurosurgery, University of Maryland School of Medicine, Baltimore, MD, United States
- *Correspondence: Abdul-Kareem Ahmed
| | - Sijia Guo
- Department of Diagnostic Radiology and Nuclear Medicine, University of Maryland School of Medicine, Baltimore, MD, United States
| | | | | | - Elias R. Melhem
- Department of Diagnostic Radiology and Nuclear Medicine, University of Maryland School of Medicine, Baltimore, MD, United States
| | - Rao P. Gullapalli
- Department of Diagnostic Radiology and Nuclear Medicine, University of Maryland School of Medicine, Baltimore, MD, United States
| | - Alexander Ksendzovsky
- Department of Neurosurgery, University of Maryland School of Medicine, Baltimore, MD, United States
| | - Howard M. Eisenberg
- Department of Neurosurgery, University of Maryland School of Medicine, Baltimore, MD, United States
| | - Timothy R. Miller
- Department of Neurosurgery, University of Maryland School of Medicine, Baltimore, MD, United States
- Department of Diagnostic Radiology and Nuclear Medicine, University of Maryland School of Medicine, Baltimore, MD, United States
| | - Dheeraj Gandhi
- Department of Neurosurgery, University of Maryland School of Medicine, Baltimore, MD, United States
- Department of Diagnostic Radiology and Nuclear Medicine, University of Maryland School of Medicine, Baltimore, MD, United States
| |
Collapse
|
14
|
Yamamoto K, Lozano AM, Fasano A. Commentary: Feasibility of Magnetic Resonance-Guided Focused Ultrasound Thalamotomy for Essential Tremor in the Setting of Prior Craniotomy. Oper Neurosurg (Hagerstown) 2022; 22:e147-e149. [PMID: 35030144 DOI: 10.1227/ons.0000000000000087] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2021] [Accepted: 10/29/2021] [Indexed: 11/19/2022] Open
Affiliation(s)
- Kazuaki Yamamoto
- Division of Neurosurgery, Toronto Western Hospital, University Health Network, University of Toronto, Toronto, Canada
| | - Andres M Lozano
- Division of Neurosurgery, Toronto Western Hospital, University Health Network, University of Toronto, Toronto, Canada.,Krembil Research Institute, Toronto, Canada
| | - Alfonso Fasano
- Krembil Research Institute, Toronto, Canada.,Edmond J. Safra Program in Parkinson's Disease, Morton and Gloria Shulman Movement Disorders Clinic, Toronto Western Hospital, University Health Network, Division of Neurology, University of Toronto, Toronto, Canada.,Center for Advancing Neurotechnological Innovation to Application (CRANIA), Toronto, Canada
| |
Collapse
|
15
|
Bancel T, Tiennot T, Aubry JF. Adaptive Ultrasound Focusing Through the Cranial Bone for Non-invasive Treatment of Brain Disorders. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2022; 1364:397-409. [DOI: 10.1007/978-3-030-91979-5_18] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
|
16
|
Kong C, Park SH, Shin J, Baek HG, Park J, Na YC, Chang WS, Chang JW. Factors Associated with Energy Efficiency of Focused Ultrasound Through the Skull: A Study of 3D-Printed Skull Phantoms and Its Comparison with Clinical Experiences. Front Bioeng Biotechnol 2021; 9:783048. [PMID: 34957077 PMCID: PMC8708563 DOI: 10.3389/fbioe.2021.783048] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2021] [Accepted: 11/15/2021] [Indexed: 11/24/2022] Open
Abstract
While focused ultrasound (FUS) is non-invasive, the ultrasound energy is attenuated by the skull which results in differences in energy efficiency among patients. In this study, we investigated the effect of skull variables on the energy efficiency of FUS. The thickness and density of the skull and proportion of the trabecular bone were selected as factors that could affect ultrasound energy transmittance. Sixteen 3D-printed skull models were designed and fabricated to reflect the three factors. The energy of each phantom was measured using an ultrasonic sound field energy measurement system. The thickness and proportion of trabecular bone affected the attenuation of transmitted energy. There was no difference in the density of the trabecular bone. In clinical data, the trabecular bone ratio showed a significantly greater correlation with dose/delivered energy than that of thickness and the skull density ratio. Currently, for clinical non-thermal FUS, the data are not sufficient, but we believe that the results of this study will be helpful in selecting patients and appropriate parameters for FUS treatment.
Collapse
Affiliation(s)
- Chanho Kong
- Department of Neurosurgery, Brain Research Institute, Yonsei University College of Medicine, Seoul, South Korea
| | - So Hee Park
- Department of Neurosurgery, Brain Research Institute, Yonsei University College of Medicine, Seoul, South Korea
| | - Jaewoo Shin
- Department of Neurosurgery, Brain Research Institute, Yonsei University College of Medicine, Seoul, South Korea
| | - Hee Gyu Baek
- Medical Device Development Center, Daegu-Gyeongbuk Medical Innovation Foundation, Daegu, South Korea
| | - Juyoung Park
- Medical Device Development Center, Daegu-Gyeongbuk Medical Innovation Foundation, Daegu, South Korea
| | - Young Cheol Na
- Department of Neurosurgery, Catholic Kwandong University College of Medicine, International St Mary's Hospital, Incheon, South Korea
| | - Won Seok Chang
- Department of Neurosurgery, Brain Research Institute, Yonsei University College of Medicine, Seoul, South Korea
| | - Jin Woo Chang
- Department of Neurosurgery, Brain Research Institute, Yonsei University College of Medicine, Seoul, South Korea
| |
Collapse
|
17
|
Kim MJ, Park SH, Chang KW, Kim Y, Gao J, Kovalevsky M, Rachmilevitch I, Zadicario E, Chang WS, Jung HH, Chang JW. Technical and operative factors affecting magnetic resonance imaging-guided focused ultrasound thalamotomy for essential tremor: experience from 250 treatments. J Neurosurg 2021; 135:1780-1788. [PMID: 34020416 DOI: 10.3171/2020.11.jns202580] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2020] [Accepted: 11/09/2020] [Indexed: 11/06/2022]
Abstract
OBJECTIVE Magnetic resonance imaging-guided focused ultrasound (MRgFUS) provides real-time monitoring of patients to assess tremor control and document any adverse effects. MRgFUS of the ventral intermediate nucleus (VIM) of the thalamus has become an effective treatment option for medically intractable essential tremor (ET). The aim of this study was to analyze the correlations of clinical and technical parameters with 12-month outcomes after unilateral MRgFUS thalamotomy for ET to help guide future clinical treatments. METHODS From October 2013 to January 2019, data on unilateral MRgFUS thalamotomy from the original pivotal study and continued-access studies from three different geographic regions were collected. Authors of the present study retrospectively reviewed those data and evaluated the efficacy of the procedure on the basis of improvement in the Clinical Rating Scale for Tremor (CRST) subscore at 1 year posttreatment. Safety was based on the rates of moderate and severe thalamotomy-related adverse events. Treatment outcomes in relation to various patient- and sonication-related parameters were analyzed in a large cohort of patients with ET. RESULTS In total, 250 patients were included in the present analysis. Improvement was sustained throughout the 12-month follow-up period, and 184 (73.6%) of 250 patients had minimal or no disability due to tremor (CRST subscore < 10) at the 12-month follow-up. Younger age and higher focal temperature (Tmax) correlated with tremor improvement in the multivariate analysis (OR 0.948, p = 0.013; OR 1.188, p = 0.025; respectively). However, no single statistically significant factor correlated with Tmax in the multivariate analysis. The cutoff value of Tmax in predicting a CRST subscore < 10 was 55.8°C. Skull density ratio (SDR) was positively correlated with heating efficiency (β = 0.005, p < 0.001), but no significant relationship with tremor improvement was observed. In the low-temperature group, 1-3 repetitions to the right target with 52°C ≤ Tmax ≤ 54°C was sufficient to generate sustained tremor suppression within the investigated follow-up period. The high-temperature group had a higher rate of balance disturbances than the low-temperature group (p = 0.04). CONCLUSIONS The authors analyzed the data of 250 patients with the aim of improving practices for patient screening and determining treatment endpoints. These results may improve the safety, efficacy, and efficiency of MRgFUS thalamotomy for ET.
Collapse
Affiliation(s)
- Myung Ji Kim
- 1Department of Neurosurgery, Brain Research Institute, Yonsei University College of Medicine, Seoul, Republic of Korea; and
| | - So Hee Park
- 1Department of Neurosurgery, Brain Research Institute, Yonsei University College of Medicine, Seoul, Republic of Korea; and
| | - Kyung Won Chang
- 1Department of Neurosurgery, Brain Research Institute, Yonsei University College of Medicine, Seoul, Republic of Korea; and
| | - Yuhee Kim
- 2InSightec Ltd., Tirat Carmel, Israel
| | - Jing Gao
- 2InSightec Ltd., Tirat Carmel, Israel
| | | | | | | | - Won Seok Chang
- 1Department of Neurosurgery, Brain Research Institute, Yonsei University College of Medicine, Seoul, Republic of Korea; and
| | - Hyun Ho Jung
- 1Department of Neurosurgery, Brain Research Institute, Yonsei University College of Medicine, Seoul, Republic of Korea; and
| | - Jin Woo Chang
- 1Department of Neurosurgery, Brain Research Institute, Yonsei University College of Medicine, Seoul, Republic of Korea; and
| |
Collapse
|
18
|
Segar DJ, Lak AM, Lee S, Harary M, Chavakula V, Lauro P, McDannold N, White J, Cosgrove GR. Lesion location and lesion creation affect outcomes after focused ultrasound thalamotomy. Brain 2021; 144:3089-3100. [PMID: 34750621 DOI: 10.1093/brain/awab176] [Citation(s) in RCA: 20] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2021] [Revised: 03/13/2021] [Accepted: 04/05/2021] [Indexed: 11/13/2022] Open
Abstract
MRI-guided focused ultrasound thalamotomy has been shown to be an effective treatment for medication refractory essential tremor. Here, we report a clinical-radiological analysis of 123 cases of MRI-guided focused ultrasound thalamotomy, and explore the relationships between treatment parameters, lesion characteristics and outcomes. All patients undergoing focused ultrasound thalamotomy by a single surgeon were included. The procedure was performed as previously described, and patients were followed for up to 1 year. MRI was performed 24 h post-treatment, and lesion locations and volumes were calculated. We retrospectively evaluated 118 essential tremor patients and five tremor-dominant Parkinson's disease patients who underwent thalamotomy. At 24 h post-procedure, tremor abated completely in the treated hand in 81 essential tremor patients. Imbalance, sensory disturbances and dysarthria were the most frequent acute adverse events. Patients with any adverse event had significantly larger lesions, while inferolateral lesion margins were associated with a higher incidence of motor-related adverse events. Twenty-three lesions were identified with irregular tails, often extending into the internal capsule; 22 of these patients experienced at least one adverse event. Treatment parameters and lesion characteristics changed with increasing surgeon experience. In later cases, treatments used higher maximum power (normalized to skull density ratio), accelerated more quickly to high power, and delivered energy over fewer sonications. Larger lesions were correlated with a rapid rise in both power delivery and temperature, while increased oedema was associated with rapid rise in temperature and the maximum power delivered. Total energy and total power did not significantly affect lesion size. A support vector regression was trained to predict lesion size and confirmed the most valuable predictors of increased lesion size as higher maximum power, rapid rise to high-power delivery, and rapid rise to high tissue temperatures. These findings may relate to a decrease in the energy efficiency of the treatment, potentially due to changes in acoustic properties of skull and tissue at higher powers and temperatures. We report the largest single surgeon series of focused ultrasound thalamotomy to date, demonstrating tremor relief and adverse events consistent with reported literature. Lesion location and volume impacted adverse events, and an irregular lesion tail was strongly associated with adverse events. High-power delivery early in the treatment course, rapid temperature rise, and maximum power were dominant predictors of lesion volume, while total power, total energy, maximum energy and maximum temperature did not improve prediction of lesion volume. These findings have critical implications for treatment planning in future patients.
Collapse
Affiliation(s)
- David J Segar
- Department of Neurosurgery, Brigham and Women's Hospital, Harvard Medical School, Boston, MA, USA
| | - Asad M Lak
- Department of Neurosurgery, Brigham and Women's Hospital, Harvard Medical School, Boston, MA, USA
| | - Shane Lee
- Department of Neuroscience, Brown University, Providence, RI, USA
| | - Maya Harary
- Department of Neurosurgery, University of California, Los Angeles, CA, USA
| | - Vamsidhar Chavakula
- Department of Neurosurgery, Brigham and Women's Hospital, Harvard Medical School, Boston, MA, USA
| | - Peter Lauro
- Department of Neuroscience, Brown University, Providence, RI, USA
| | - Nathan McDannold
- Department of Radiology, Brigham and Women's Hospital, Harvard Medical School, Boston, MA, USA
| | - Jason White
- Department of Radiology, Brigham and Women's Hospital, Harvard Medical School, Boston, MA, USA
| | - G Rees Cosgrove
- Department of Neurosurgery, Brigham and Women's Hospital, Harvard Medical School, Boston, MA, USA
| |
Collapse
|
19
|
Hori H, Iwamuro H, Nakano M, Ouchi T, Kawahara T, Taira T, Abe K, Iijima K, Yamaguchi T. Correction of the skull density ratio for transcranial MRI-guided focused ultrasound thalamotomy: clinical significance of predicting therapeutic temperature. J Neurosurg 2021; 135:1436-1444. [PMID: 33668032 DOI: 10.3171/2020.9.jns201109] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2020] [Accepted: 09/04/2020] [Indexed: 11/06/2022]
Abstract
OBJECTIVE In transcranial magnetic resonance imaging-guided focused ultrasound (TcMRgFUS), a high skull density ratio (SDR) is advantageous to achieve a sufficiently high temperature at the target. However, it is not easy to estimate the temperature rise because the SDR shows different values depending on the reconstruction filter used. The resolution characteristic of a computed tomography (CT) image depends on a modulation transfer function (MTF) defined by the reconstruction filter. Differences in MTF induce unstable SDRs. The purpose of this study was both to standardize SDR by developing a method to correct the MTF and to enable effective patient screening prior to TcMRgFUS treatment and more accurate predictions of focal temperature. METHODS CT images of a skull phantom and five subjects were obtained using eight different reconstruction filters. A frequency filter (FF) was calculated using the MTF of each reconstruction filter, and the validity of SDR standardization was evaluated by comparing the variation in SDR before and after FF correction. Subsequently, FF processing was similarly performed using the CT images of 18 patients who had undergone TcMRgFUS, and statistical analyses were performed comparing the relationship between the SDRs before and after correction and the maximum temperature in the target during TcMRgFUS treatment. RESULTS The FF was calculated for each reconstruction filter based on one manufacturer's BONE filter. In the CT images of the skull phantom, the SDR before FF correction with five of the other seven reconstruction filters was significantly smaller than that with the BONE filter (p < 0.01). After FF correction, however, a significant difference was recognized under only one condition. In the CT images of the five subjects, variation of the SDR due to imaging conditions was significantly improved after the FF correction. In 18 cases treated with TcMRgFUS, there was no correlation between SDR before FF correction and maximum temperature (rs = 0.31, p > 0.05); however, a strong positive correlation was observed after FF correction (rs = 0.71, p < 0.01). CONCLUSIONS After FF correction, the difference in SDR due to the reconstruction filter used is smaller, and the correlation with temperature is stronger. Therefore, the SDR can be standardized by applying the FF, and the maximum temperature during treatment may be predicted more accurately.
Collapse
Affiliation(s)
| | - Hirokazu Iwamuro
- 6Department of Neurosurgery, Juntendo University, Bunkyo, Tokyo; and
| | | | | | | | - Takaomi Taira
- 7Department of Neurosurgery, Tokyo Women's Medical University, Shinjuku, Tokyo, Japan
| | - Keiichi Abe
- 7Department of Neurosurgery, Tokyo Women's Medical University, Shinjuku, Tokyo, Japan
| | - Ken Iijima
- 5Department of Diagnostic Radiology, Shin-Yurigaoka General Hospital, Kawasaki, Kanagawa
| | | |
Collapse
|
20
|
Davidson B, Hamani C, Huang Y, Jones RM, Meng Y, Giacobbe P, Lipsman N. Magnetic Resonance-Guided Focused Ultrasound Capsulotomy for Treatment-Resistant Psychiatric Disorders. Oper Neurosurg (Hagerstown) 2021; 19:741-749. [PMID: 32735671 DOI: 10.1093/ons/opaa240] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2020] [Accepted: 05/27/2020] [Indexed: 12/19/2022] Open
Abstract
BACKGROUND Psychiatric surgery is an important domain of functional neurosurgery and involves deep brain stimulation (DBS) or lesional procedures performed for treatment-resistant psychiatric illness. It has recently become possible to use magnetic-guided focused ultrasound (MRgFUS) to perform bilateral capsulotomy, a lesional technique commonly carried out with surgical radiofrequency ablation or stereotactic radiosurgery. MRgFUS offers several advantages, including improved safety and real-time imaging of the lesions. OBJECTIVE To describe the clinical and technical aspects of performing bilateral MRgFUS capsulotomy in patients with severe refractory depression and obsessive-compulsive disorder. METHODS We describe the clinical and technical considerations of performing MRgFUS capsulotomy. Topics discussed include patient selection, headframe application, targeting, sonication strategies, and follow-up procedures. RESULTS MRgFUS capsulotomy was performed in 16 patients without serious clinical or radiographic adverse events. CONCLUSION MRgFUS allows for a safe, less invasive technique for performing a well-studied psychiatric surgery procedure-the anterior capsulotomy.
Collapse
Affiliation(s)
- Benjamin Davidson
- Division of Neurosurgery, Sunnybrook Health Sciences Centre, University of Toronto, Toronto, Canada.,Harquail Centre for Neuromodulation, Hurvitz Brain Sciences Program, Sunnybrook Research Institute, Toronto, Canada.,Sunnybrook Research Institute, Toronto Canada
| | - Clement Hamani
- Division of Neurosurgery, Sunnybrook Health Sciences Centre, University of Toronto, Toronto, Canada.,Harquail Centre for Neuromodulation, Hurvitz Brain Sciences Program, Sunnybrook Research Institute, Toronto, Canada.,Sunnybrook Research Institute, Toronto Canada
| | - Yuexi Huang
- Sunnybrook Research Institute, Toronto Canada.,Physical Sciences Platform, Sunnybrook Research Institute, Toronto, Canada
| | - Ryan M Jones
- Sunnybrook Research Institute, Toronto Canada.,Physical Sciences Platform, Sunnybrook Research Institute, Toronto, Canada
| | - Ying Meng
- Division of Neurosurgery, Sunnybrook Health Sciences Centre, University of Toronto, Toronto, Canada.,Harquail Centre for Neuromodulation, Hurvitz Brain Sciences Program, Sunnybrook Research Institute, Toronto, Canada.,Sunnybrook Research Institute, Toronto Canada
| | - Peter Giacobbe
- Harquail Centre for Neuromodulation, Hurvitz Brain Sciences Program, Sunnybrook Research Institute, Toronto, Canada.,Sunnybrook Research Institute, Toronto Canada.,Department of Psychiatry, Sunnybrook Health Sciences Centre, Toronto, Canada
| | - Nir Lipsman
- Division of Neurosurgery, Sunnybrook Health Sciences Centre, University of Toronto, Toronto, Canada.,Harquail Centre for Neuromodulation, Hurvitz Brain Sciences Program, Sunnybrook Research Institute, Toronto, Canada.,Sunnybrook Research Institute, Toronto Canada
| |
Collapse
|
21
|
Yang AI, Hitti FL, Alabi OO, Joshi D, Chaibainou H, Henry L, Clanton R, Baltuch GH. Patient-specific effects on sonication heating efficiency during magnetic resonance-guided focused ultrasound thalamotomy. Med Phys 2021; 48:6588-6596. [PMID: 34532858 DOI: 10.1002/mp.15239] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2021] [Revised: 09/07/2021] [Accepted: 09/07/2021] [Indexed: 01/09/2023] Open
Abstract
PURPOSE During magnetic resonance-guided focused ultrasound (MRgFUS) thalamotomy for refractory tremor, high temperatures must be achieved and sustained for tissue necrosis. We assessed the impact of both patient-specific as well as procedure-related factors on the efficiency of acoustic energy transfer, or heating efficiency (HE). METHODS Retrospective analysis of 92 consecutive patients (857 sonications) with essential tremor or tremor-dominant Parkinson's disease treated at a single institution. Temperature elevations at the target were measured for each sonication with MR thermometry. HE of each sonication was defined as the ratio of peak temperature elevation and the delivered energy. HE was analyzed with respect to patient skull features (area, thickness, skull density ratio [SDR]), computed from CT scans, as well as demographic and clinical variables (age, sex, diagnosis, and duration of symptoms). RESULTS Across the full range of sonication energies that can be delivered with current devices (up to 36 kJ), average sonication HE was diminished in patients with lower SDR. In individual subjects, there was a progressive loss in HE as sonication energy was titrated up throughout the course of treatment, with a more rapid decline in patients with higher SDR. This energy-dependent loss in HE was not related to procedural factors, namely, the number of previous sonications, or the cumulative energy deposited during previous sonications. In contrast to SDR, neither skull area nor thickness was an independent predictor of average HE or the rate of its decline with increasing energies. In 11% of patients, all of whom with SDR < 0.45, sonication HE fell below the threshold to reach 54°C even with delivery of maximum energy. In contrast, temperatures ≥ 50°C could be obtained in all but one patient. CONCLUSIONS SDR is predictive of sonication HE, and determines patient-specific limits on the magnitude of temperature elevation that can be achieved with current devices. These data inform strategies for predictable lesioning in MRgFUS thalamotomy.
Collapse
Affiliation(s)
- Andrew I Yang
- Department of Neurosurgery, University of Pennsylvania, Philadelphia, Pennsylvania, USA
| | - Frederick L Hitti
- Department of Neurosurgery, University of Pennsylvania, Philadelphia, Pennsylvania, USA
| | - Opeyemi O Alabi
- Department of Neurosurgery, University of Pennsylvania, Philadelphia, Pennsylvania, USA
| | - Disha Joshi
- Department of Neurosurgery, University of Pennsylvania, Philadelphia, Pennsylvania, USA
| | - Hanane Chaibainou
- Department of Neurosurgery, University of Pennsylvania, Philadelphia, Pennsylvania, USA
| | | | | | - Gordon H Baltuch
- Department of Neurosurgery, University of Pennsylvania, Philadelphia, Pennsylvania, USA
| |
Collapse
|
22
|
Tommasino E, Bruno F, Catalucci A, Varrassi M, Sucapane P, Cerone D, Pistoia F, Di Cesare E, Barile A, Ricci A, Marini C, Masciocchi C, Splendiani A. Prognostic value of brain tissues' volumes in patients with essential tremor treated with MRgFUS thalamotomy. J Clin Neurosci 2021; 92:33-38. [PMID: 34509258 DOI: 10.1016/j.jocn.2021.07.051] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2020] [Revised: 06/08/2021] [Accepted: 07/25/2021] [Indexed: 01/05/2023]
Abstract
MRgFUS Vim thalamotomy is a novel, effective, minimally invasive therapeutic option for patients with essential tremor (ET). Among the selection criteria, some parameters related to the patient's anatomy, such as the skull density ratio (SDR), are well recognized. The role of brain tissue interposed between the target and the ultrasound transducers has never been explored. Therefore, the purpose of our study was to evaluate the correlation and the possible predictive value between brain tissue volumes (grey matter - GM, white matter - WM, and cerebrospinal fluid - CSF) and several treatment-related variables (periprocedural parameters, MRI imaging findings, and the clinical outcome). We analysed data from thirty ET patients previously submitted to MRgFUS thalamotomy. Pre-treatment images were automatically segmented in sopra-tentorial (ST) WM, GM, and CSF using SPM 12. The most significant findings were a positive correlation of the ST-GM with the Accumulated Thermal Dose (ATD) (p < 0,001) and a negative correlation of the ATD temperature with ST-CSF and ST-TIV (p < 0,001). Ultrasound propagation speed is lower in fluids than brain tissues. Also, WM has an attenuation rate of 1.5 higher than the GM. Therefore, the difference in the ATD may be explained by the different acoustic properties of normal brain tissues interposed between the transducers and the VIM.
Collapse
Affiliation(s)
- E Tommasino
- Department of Biotechnological and Applied Clinical Science, University of L'Aquila AQ, Via Vetoio 1 AQ, 67100, Italy.
| | - F Bruno
- Department of Biotechnological and Applied Clinical Science, University of L'Aquila AQ, Via Vetoio 1 AQ, 67100, Italy
| | - A Catalucci
- Department of Biotechnological and Applied Clinical Science, University of L'Aquila AQ, Via Vetoio 1 AQ, 67100, Italy
| | - M Varrassi
- Department of Biotechnological and Applied Clinical Science, University of L'Aquila AQ, Via Vetoio 1 AQ, 67100, Italy
| | - P Sucapane
- Neurology Unit, San Salvatore Hospital, L'Aquila, Italy
| | - D Cerone
- Neurology Unit, San Salvatore Hospital, L'Aquila, Italy
| | - F Pistoia
- Department of Biotechnological and Applied Clinical Science, University of L'Aquila AQ, Via Vetoio 1 AQ, 67100, Italy
| | - E Di Cesare
- Department of Biotechnological and Applied Clinical Science, University of L'Aquila AQ, Via Vetoio 1 AQ, 67100, Italy
| | - A Barile
- Department of Biotechnological and Applied Clinical Science, University of L'Aquila AQ, Via Vetoio 1 AQ, 67100, Italy
| | - A Ricci
- Department of Neurosurgery, University of L'Aquila AQ, Via Vetoio 1 AQ, 67100, Italy
| | - C Marini
- Department of Life, Health and Environmental Sciences, University of L'Aquila, Italy
| | - C Masciocchi
- Department of Biotechnological and Applied Clinical Science, University of L'Aquila AQ, Via Vetoio 1 AQ, 67100, Italy.
| | - A Splendiani
- Department of Biotechnological and Applied Clinical Science, University of L'Aquila AQ, Via Vetoio 1 AQ, 67100, Italy.
| |
Collapse
|
23
|
Zhang M, Rodrigues A, Zhou Q, Li G. Focused ultrasound: growth potential and future directions in neurosurgery. J Neurooncol 2021; 156:23-32. [PMID: 34410576 DOI: 10.1007/s11060-021-03820-9] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2021] [Accepted: 07/31/2021] [Indexed: 12/18/2022]
Abstract
Over the past two decades, vast improvements in focused ultrasound (FUS) technology have made the therapy an exciting addition to the neurosurgical armamentarium. In this time period, FUS has gained US Food and Drug Administration (FDA) approval for the treatment of two neurological disorders, and ongoing efforts seek to expand the lesion profile that is amenable to ultrasonic intervention. In the following review, we highlight future applications for FUS therapy and compare its potential role against established technologies, including deep brain stimulation and stereotactic radiosurgery. Particular attention is paid to tissue ablation, blood-brain-barrier opening, and gene therapy. We also address technical and infrastructural challenges involved with FUS use and summarize the hurdles that must be overcome before FUS becomes widely accepted in the neurosurgical community.
Collapse
Affiliation(s)
- Michael Zhang
- Department of Neurosurgery, Stanford University School of Medicine, Stanford, CA, USA. .,Center for Academic Medicine, Neurosurgery, Stanford University School of Medicine, MC 5327, 453 Quarry Road, Palo Alto, CA, 94304, USA.
| | - Adrian Rodrigues
- Department of Neurosurgery, Stanford University School of Medicine, Stanford, CA, USA
| | - Quan Zhou
- Department of Neurosurgery, Stanford University School of Medicine, Stanford, CA, USA.,Department of Otolaryngology-Head and Neck Surgery, Stanford University School of Medicine, Stanford, CA, USA
| | - Gordon Li
- Department of Neurosurgery, Stanford University School of Medicine, Stanford, CA, USA
| |
Collapse
|
24
|
Davidson B, Mithani K, Huang Y, Jones RM, Goubran M, Meng Y, Snell J, Hynynen K, Hamani C, Lipsman N. Technical and radiographic considerations for magnetic resonance imaging-guided focused ultrasound capsulotomy. J Neurosurg 2021; 135:291-299. [PMID: 32977311 DOI: 10.3171/2020.6.jns201302] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2020] [Accepted: 06/04/2020] [Indexed: 11/06/2022]
Abstract
OBJECTIVE Magnetic resonance imaging-guided focused ultrasound (MRgFUS) is an emerging treatment modality that enables incisionless ablative neurosurgical procedures. Bilateral MRgFUS capsulotomy has recently been demonstrated to be safe and effective in treating obsessive-compulsive disorder (OCD) and major depressive disorder (MDD). Preliminary evidence has suggested that bilateral MRgFUS capsulotomy can present increased difficulties in reaching lesional temperatures as compared to unilateral thalamotomy. The authors of this article aimed to study the parameters associated with successful MRgFUS capsulotomy lesioning and to present longitudinal radiographic findings following MRgFUS capsulotomy. METHODS Using data from 22 attempted MRgFUS capsulotomy treatments, the authors investigated the relationship between various sonication parameters and the maximal temperature achieved at the intracranial target. Lesion volume and morphology were analyzed longitudinally using structural and diffusion tensor imaging. A retreatment procedure was attempted in one patient, and their postoperative imaging is presented. RESULTS Skull density ratio (SDR), skull thickness, and angle of incidence were significantly correlated with the maximal temperature achieved. MRgFUS capsulotomy lesions appeared similar to those following MRgFUS thalamotomy, with three concentric zones observed on MRI. Lesion volumes regressed substantially over time following MRgFUS. Fractional anisotropy analysis revealed a disruption in white matter integrity, followed by a gradual return to near-baseline levels concurrent with lesion regression. In the patient who underwent retreatment, successful bilateral lesioning was achieved, and there were no adverse clinical or radiographic events. CONCLUSIONS With the current iteration of MRgFUS technology, skull-related parameters such as SDR, skull thickness, and angle of incidence should be considered when selecting patients suitable for MRgFUS capsulotomy. Lesions appear to follow morphological patterns similar to what is seen following MRgFUS thalamotomy. Retreatment appears to be safe, although additional cases will be necessary to further evaluate the associated safety profile.
Collapse
Affiliation(s)
- Benjamin Davidson
- 1Division of Neurosurgery, Sunnybrook Health Sciences Centre
- 2Harquail Centre for Neuromodulation and Hurvitz Brain Sciences Program
- 3Sunnybrook Research Institute
| | - Karim Mithani
- 1Division of Neurosurgery, Sunnybrook Health Sciences Centre
- 2Harquail Centre for Neuromodulation and Hurvitz Brain Sciences Program
- 3Sunnybrook Research Institute
| | - Yuexi Huang
- 3Sunnybrook Research Institute
- 4Physical Sciences Platform, Sunnybrook Research Institute, Toronto, Ontario, Canada
| | - Ryan M Jones
- 3Sunnybrook Research Institute
- 4Physical Sciences Platform, Sunnybrook Research Institute, Toronto, Ontario, Canada
| | - Maged Goubran
- 2Harquail Centre for Neuromodulation and Hurvitz Brain Sciences Program
- 3Sunnybrook Research Institute
- 4Physical Sciences Platform, Sunnybrook Research Institute, Toronto, Ontario, Canada
- 7Department of Medical Biophysics, University of Toronto; and
| | - Ying Meng
- 1Division of Neurosurgery, Sunnybrook Health Sciences Centre
- 2Harquail Centre for Neuromodulation and Hurvitz Brain Sciences Program
- 3Sunnybrook Research Institute
| | - John Snell
- 5The Focused Ultrasound Foundation, Charlottesville
- 6Department of Neurosurgery, University of Virginia, Charlottesville, Virginia
| | - Kullervo Hynynen
- 2Harquail Centre for Neuromodulation and Hurvitz Brain Sciences Program
- 3Sunnybrook Research Institute
- 4Physical Sciences Platform, Sunnybrook Research Institute, Toronto, Ontario, Canada
- 7Department of Medical Biophysics, University of Toronto; and
- 8Institute of Biomaterials and Biomedical Engineering, Toronto, Ontario, Canada
| | - Clement Hamani
- 1Division of Neurosurgery, Sunnybrook Health Sciences Centre
- 2Harquail Centre for Neuromodulation and Hurvitz Brain Sciences Program
- 3Sunnybrook Research Institute
| | - Nir Lipsman
- 1Division of Neurosurgery, Sunnybrook Health Sciences Centre
- 2Harquail Centre for Neuromodulation and Hurvitz Brain Sciences Program
- 3Sunnybrook Research Institute
| |
Collapse
|
25
|
Bancel T, Houdouin A, Annic P, Rachmilevitch I, Shapira Y, Tanter M, Aubry JF. Comparison Between Ray-Tracing and Full-Wave Simulation for Transcranial Ultrasound Focusing on a Clinical System Using the Transfer Matrix Formalism. IEEE TRANSACTIONS ON ULTRASONICS, FERROELECTRICS, AND FREQUENCY CONTROL 2021; 68:2554-2565. [PMID: 33651688 DOI: 10.1109/tuffc.2021.3063055] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
Only one high-intensity focused ultrasound device has been clinically approved for transcranial brain surgery at the time of writing. The device operates within 650 and 720 kHz and corrects the phase distortions induced by the skull of each patient using a multielement phased array. Phase correction is estimated adaptively using a proprietary algorithm based on computed-tomography (CT) images of the patient's skull. In this article, we assess the performance of the phase correction computed by the clinical device and compare it to: 1) the correction obtained with a previously validated full-wave simulation algorithm using an open-source pseudo-spectral toolbox and 2) a hydrophone-based correction performed invasively to measure the aberrations induced by the skull at 650 kHz. For the full-wave simulation, three different mappings between CT Hounsfield units and the longitudinal speed of sound inside the skull were tested. All methods are compared with the exact same setup due to transfer matrices acquired with the clinical system for N = 5 skulls and T = 2 different targets for each skull. We show that the clinical ray-tracing software and the full-wave simulation restore, respectively, 84% ± 5% and 86% ± 5% of the pressure obtained with hydrophone-based correction for targets located in central brain regions. On the second target (off-center), we also report that the performance of both algorithms degrades when the average incident angles of the acoustic beam at the skull surface increase. When incident angles are higher than 20°, the restored pressure drops below 75% of the pressure restored with hydrophone-based correction.
Collapse
|
26
|
Tsai KWK, Chen JC, Lai HC, Chang WC, Taira T, Chang JW, Wei CY. The Distribution of Skull Score and Skull Density Ratio in Tremor Patients for MR-Guided Focused Ultrasound Thalamotomy. Front Neurosci 2021; 15:612940. [PMID: 34079434 PMCID: PMC8165389 DOI: 10.3389/fnins.2021.612940] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2020] [Accepted: 04/08/2021] [Indexed: 12/20/2022] Open
Abstract
Objective Magnetic resonance-guided focused ultrasound (MRgFUS) is a minimum-invasive surgical approach to non-incisionally cause the thermos-coagulation inside the human brain. The skull score (SS) has already been approved as one of the most dominant factors related to a successful MRgFUS treatment. In this study, we first reveal the SS distribution of the tremor patients, and correlate the SS with the image feature from customized skull density ratio (cSDR). This correlation might give a direction to future clinical studies for improving the SS. Methods Two hundred and forty-six patients received a computed tomography (CT) scan of the brain, and a bone-enhanced filter was applied and reconstructed to a high spatial resolution CT images. The SS of all patients would be estimated by the MRgFUS system after importing the reconstructed CT images into the MRgFUS system. The histogram and the cumulative distribution of the SS from all the patients were calculated to show the percentage of the patients whose SS lower than 0.3 and 0.4. The same CT images of all patients were utilized to calculated the cSDR by first segmented the trabecular bone and the cortical bone from the CT images and divided the average trabecular bone intensity (aTBI) by the average cortical bone intensity (aCBI). The Pearson’s correlations between the SS and the cSDR, aTBI, and the aCBI were calculated, respectively. Results There were 19.19 and 50% of the patient who had the SS lower than the empirical threshold 0.3 and 0.4, respectively. The Pearson’s correlation between the SS and the cSDR, aCBI, and the aTBI were R = 0.8145, 0.5723, and 0.8842. Conclusion Half of the patients were eligible for the MRgFUS thalamotomy based on the SS, and nearly 20% of patients were empirically difficult to achieve a therapeutic temperature during MRgFUS. The SS and our cSDR are highly correlated, and the SS had a higher correlation with aTBI than with aCBI. This is the first report to explicitly reveal the SS population and indicate a potential way to increase the chance to achieve a therapeutic temperature for those who originally have low SS.
Collapse
Affiliation(s)
- Kevin Wen-Kai Tsai
- MR-guided Focused Ultrasound Center, Chang Bing Show Chwan Memorial Hospital, Changhua City, Taiwan
| | - Jui-Cheng Chen
- Neuroscience Laboratory, Department of Neurology, China Medical University Hospital, Taichung City, Taiwan.,School of Medicine, College of Medicine, China Medical University, Taichung City, Taiwan.,Department of Neurology, China Medical University Hsinchu Hospital, Hsinchu, Taiwan
| | - Hui-Chin Lai
- MR-guided Focused Ultrasound Center, Chang Bing Show Chwan Memorial Hospital, Changhua City, Taiwan
| | - Wei-Chieh Chang
- MR-guided Focused Ultrasound Center, Chang Bing Show Chwan Memorial Hospital, Changhua City, Taiwan.,Department of Neurosurgery, Chang Bing Show Chwan Memorial Hospital, Changhua City, Taiwan
| | - Takaomi Taira
- Department of Neurosurgery, Tokyo Women's Medical University, Tokyo, Japan
| | - Jin Woo Chang
- Department of Neurosurgery, Yonsei University College of Medicine, Seoul, South Korea
| | - Cheng-Yu Wei
- Department of Exercise and Health Promotion, College of Kinesiology and Health, Chinese Culture University, Taipei, Taiwan.,Department of Neurology, Chang Bing Show Chwan Memorial Hospital, Changhua City, Taiwan
| |
Collapse
|
27
|
López-Aguirre M, Caballero-Insaurriaga J, Urso D, Rodríguez-Rojas R, Máñez-Miró JU, Del-Alamo M, Rachmilevitch I, Martínez-Fernández R, Pineda-Pardo JA. Lesion 3D modeling in transcranial MR-guided focused ultrasound thalamotomy. Magn Reson Imaging 2021; 80:71-80. [PMID: 33905832 DOI: 10.1016/j.mri.2021.04.003] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2020] [Revised: 04/08/2021] [Accepted: 04/21/2021] [Indexed: 01/21/2023]
Abstract
Transcranial magnetic resonance-guided focused ultrasound (tMRgFUS) allows to perform incisionless thermoablation of deep brain structures. This feature makes it a very useful tool for the treatment of multiple neurological and psychiatric disorders. Currently, feedback of the thermoablation process is based on peak temperature readings assessed on real-time two-dimensional MRI thermometry. However, an accurate methodology relating thermal dosimetry with three-dimensional topography and temporal evolution of the lesion is still to be defined, thus hurdling the establishment of well-defined, evidence-based criteria to perform safe and effective treatments. In here we propose threshold-based thermoablation models to predict the volumetric topography of the lesion (whole lesion and necrotic core) in the short-to-mid-term based on thermal dosimetry estimated from intra-treatment MRI thermometry. To define and validate our models we retrospectively analyzed the data of sixty-three tMRgFUS thalamotomies for treating tremor. We used intra-treatment MRI thermometry to estimate whole-treatment three-dimensional thermal dose maps, defined either as peak temperature reached (Tmax) or thermal isoeffective dose (TID). Those maps were thresholded to find the dosimetric level that maximize the agreement (Sorensen-Dice coefficient - SDc) with the boundaries of the whole lesion and its core, assessed on T2w images 1-day (post-24h) and 3-months (post-3M) after treatment. Best predictions were achieved for the whole lesion at post-24h (SDc = 0.71), with Tmax /TID over 50.0 °C/90.5 CEM43. The core at post-24h and whole lesion at post-3M lesions reported a similar behavior in terms of shape accuracy (SDc ~0.35), and thermal dose thresholds ~55 °C/4100.0 CEM43. Finally, the optimal levels for post-3M core lesions were 55.5 °C/5800.0 CEM43 (SDc = 0.21). These thermoablation models could contribute to the real-time decision-making process and improve the outcome of tMRgFUS interventions both in terms of safety and efficacy.
Collapse
Affiliation(s)
- Miguel López-Aguirre
- HM CINAC, Centro Integral de Neurociencias AC, Hospital Universitario HM Puerta del Sur, HM Hospitales, Madrid, Spain; Universidad Complutense de Madrid, Madrid, Spain
| | - Jaime Caballero-Insaurriaga
- HM CINAC, Centro Integral de Neurociencias AC, Hospital Universitario HM Puerta del Sur, HM Hospitales, Madrid, Spain; Universidad Politécnica de Madrid, Madrid, Spain
| | - Daniele Urso
- King's College (KCL), Institute of Psychiatry, Psychology & Neuroscience, London, United Kingdom
| | - Rafael Rodríguez-Rojas
- HM CINAC, Centro Integral de Neurociencias AC, Hospital Universitario HM Puerta del Sur, HM Hospitales, Madrid, Spain; Universidad San Pablo CEU, Madrid, Spain; Centro de Investigación Biomédica en Red de Enfermedades Neurodegenerativas Instituto Carlos III, Madrid, Spain
| | - Jorge U Máñez-Miró
- HM CINAC, Centro Integral de Neurociencias AC, Hospital Universitario HM Puerta del Sur, HM Hospitales, Madrid, Spain
| | - Marta Del-Alamo
- HM CINAC, Centro Integral de Neurociencias AC, Hospital Universitario HM Puerta del Sur, HM Hospitales, Madrid, Spain
| | | | - Raúl Martínez-Fernández
- HM CINAC, Centro Integral de Neurociencias AC, Hospital Universitario HM Puerta del Sur, HM Hospitales, Madrid, Spain; Universidad San Pablo CEU, Madrid, Spain; Centro de Investigación Biomédica en Red de Enfermedades Neurodegenerativas Instituto Carlos III, Madrid, Spain
| | - José A Pineda-Pardo
- HM CINAC, Centro Integral de Neurociencias AC, Hospital Universitario HM Puerta del Sur, HM Hospitales, Madrid, Spain; Universidad San Pablo CEU, Madrid, Spain; Centro de Investigación Biomédica en Red de Enfermedades Neurodegenerativas Instituto Carlos III, Madrid, Spain.
| |
Collapse
|
28
|
Leung SA, Moore D, Webb TD, Snell J, Ghanouni P, Butts Pauly K. Transcranial focused ultrasound phase correction using the hybrid angular spectrum method. Sci Rep 2021; 11:6532. [PMID: 33753771 PMCID: PMC7985511 DOI: 10.1038/s41598-021-85535-5] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2020] [Accepted: 02/25/2021] [Indexed: 12/17/2022] Open
Abstract
The InSightec Exablate system is the standard of care used for transcranial focused ultrasound ablation treatments in the United States. The system calculates phase corrections that account for aberrations caused by the human skull. This work investigates whether skull aberration correction can be improved by comparing the standard of care InSightec ray tracing method with the hybrid angular spectrum (HAS) method and the gold standard hydrophone method. Three degassed ex vivo human skulls were sonicated with a 670 kHz hemispherical phased array transducer (InSightec Exablate 4000). Phase corrections were calculated using four different methods (straight ray tracing, InSightec ray tracing, HAS, and hydrophone) and were used to drive the transducer. 3D raster scans of the beam profiles were acquired using a hydrophone mounted on a 3-axis positioner system. Focal spots were evaluated using six metrics: pressure at the target, peak pressure, intensity at the target, peak intensity, positioning error, and focal spot volume. For three skulls, the InSightec ray tracing method achieved 52 ± 21% normalized target intensity (normalized to hydrophone), 76 ± 17% normalized peak intensity, and 0.72 ± 0.47 mm positioning error. The HAS method achieved 74 ± 9% normalized target intensity, 81 ± 9% normalized peak intensity, and 0.35 ± 0.09 mm positioning error. The InSightec-to-HAS improvement in focal spot targeting provides promise in improving treatment outcomes. These improvements to skull aberration correction are also highly relevant for the applications of focused ultrasound neuromodulation and blood brain barrier opening, which are currently being translated for human use.
Collapse
Affiliation(s)
- Steven A Leung
- Department of Bioengineering, Stanford University, Stanford, CA, USA.
| | - David Moore
- Focused Ultrasound Foundation, Charlottesville, VA, USA
| | - Taylor D Webb
- Department of Electrical Engineering, Stanford University, Stanford, CA, USA
| | - John Snell
- Focused Ultrasound Foundation, Charlottesville, VA, USA
- Department of Neurological Surgery, University of Virginia, Charlottesville, VA, USA
| | - Pejman Ghanouni
- Department of Radiology, Stanford University, Stanford, CA, USA
| | - Kim Butts Pauly
- Department of Bioengineering, Stanford University, Stanford, CA, USA
- Department of Electrical Engineering, Stanford University, Stanford, CA, USA
- Department of Radiology, Stanford University, Stanford, CA, USA
| |
Collapse
|
29
|
Chang SJ, Luca CC, Jagid JR. Commentary: Focused Ultrasound Thalamotomy for Refractory Essential Tremor: A Japanese Multicenter Single-Arm Study. Neurosurgery 2021; 88:E310-E311. [PMID: 33471894 DOI: 10.1093/neuros/nyaa543] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2020] [Accepted: 10/19/2020] [Indexed: 11/14/2022] Open
Affiliation(s)
- Stephano J Chang
- Department of Neurological Surgery, University of Miami Miller School of Medicine, Miami, Florida.,Department of Neurosurgery, University of British Columbia, Vancouver, Canada
| | - Corneliu C Luca
- Department of Neurology, University of Miami Miller School of Medicine, Miami, Florida
| | - Jonathan R Jagid
- Department of Neurological Surgery, University of Miami Miller School of Medicine, Miami, Florida
| |
Collapse
|
30
|
Chang KW, Rachmilevitch I, Chang WS, Jung HH, Zadicario E, Prus O, Chang JW. Safety and Efficacy of Magnetic Resonance-Guided Focused Ultrasound Surgery With Autofocusing Echo Imaging. Front Neurosci 2021; 14:592763. [PMID: 33510610 PMCID: PMC7835836 DOI: 10.3389/fnins.2020.592763] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2020] [Accepted: 11/30/2020] [Indexed: 02/01/2023] Open
Abstract
Objective Magnetic resonance-guided focused ultrasound surgery (MRgFUS) lesioning is a new treatment for brain disorders. However, the skull is a major barrier of ultrasound sonication in MRgFUS because it has an irregular surface and varies its size and shape among individuals. We recently developed the concept of skull density ratio (SDR) to select candidates for MRgFUS from among patients with essential tremor (ET). However, SDR is not the only factor contributing to successful MRgFUS lesioning treatment-refining the target through exact measurement of the ultrasonic echo in the transducer also improves treatment efficacy. In the present study, we carried out MRgFUS lesioning using an autofocusing echo imaging technique. We aimed to evaluate the safety and efficacy of this new approach, especially in patients with low SDR in whom previous focusing methods have failed. Methods From December 2019 to March 2020, we recruited 10 patients with ET or Parkinson's disease (PD) who had a low SDR. Two patients dropped out of the trial due to the screening failure of other medical diseases. In total, eight patients were included: six with ET who underwent MRgFUS thalamotomy and two with PD who underwent MRgFUS pallidotomy. The autofocusing echo imaging technique was used in all cases. Results The mean SDR of the patients with ET was 0.34 (range: 0.29-0.39), while that of the patients with PD was 0.41 (range: 0.38-0.44). The mean skull volume of patients with ET was 280.57 cm3 (range: 227-319 cm3), while that of the patients with PD was 287.13 cm3 (range: 271-303 cm3). During MRgFUS, a mean of 15 sonications were performed, among which a mean of 5.63 used the autofocusing technique. The mean maximal temperature (Tmax) achieved was 55.88°C (range: 52-59°C), while the mean energy delivered was 34.75 kJ (range: 20-42 kJ) among all patients. No serious adverse events occurred during or after treatment. Tmax or sonication factors (skull volume, SDR, sonication number, autofocusing score, similarity score, energy range, and power) were not correlated with autofocusing technique (p > 0.05, autofocusing score showed a p-value of 0.071). Conclusion Using autofocusing echo imaging lesioning, a safe and efficient MRgFUS treatment, is available even for patients with a low SDR. Therefore, the indications for MRgFUS lesioning could be expanded to include patients with ET who have an SDR < 0.4 and those with PD who have an SDR < 0.45. Clinical Trial Registration clinicaltrials.gov, identifier: NCT03935581.
Collapse
Affiliation(s)
- Kyung Won Chang
- Department of Neurosurgery, Brain Research Institute, Yonsei University College of Medicine, Seoul, South Korea
| | | | - Won Seok Chang
- Department of Neurosurgery, Brain Research Institute, Yonsei University College of Medicine, Seoul, South Korea
| | - Hyun Ho Jung
- Department of Neurosurgery, Brain Research Institute, Yonsei University College of Medicine, Seoul, South Korea
| | | | | | - Jin Woo Chang
- Department of Neurosurgery, Brain Research Institute, Yonsei University College of Medicine, Seoul, South Korea
| |
Collapse
|
31
|
Belzberg M, Mahapatra S, Perdomo-Pantoja A, Chavez F, Morrison K, Xiong KT, Gamo NJ, Restaino S, Thakor N, Yazdi Y, Iyer R, Tyler B, Theodore N, Luciano MG, Brem H, Groves M, Cohen AR, Manbachi A. Minimally invasive therapeutic ultrasound: Ultrasound-guided ultrasound ablation in neuro-oncology. ULTRASONICS 2020; 108:106210. [PMID: 32619834 PMCID: PMC8895244 DOI: 10.1016/j.ultras.2020.106210] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/22/2019] [Revised: 05/28/2020] [Accepted: 06/12/2020] [Indexed: 05/19/2023]
Abstract
INTRODUCTION To improve patient outcomes (eg, reducing blood loss and infection), practitioners have gravitated toward noninvasive and minimally invasive surgeries (MIS), which demand specialized toolkits. Focused ultrasound, for example, facilitates thermal ablation from a distance, thereby reducing injury to surrounding tissue. Focused ultrasound can often be performed noninvasively; however, it is more difficult to carry out in neuro-oncological tumors, as ultrasound is dramatically attenuated while propagating through the skull. This shortcoming has prompted exploration of MIS options for intracranial placement of focused ultrasound probes, such as within the BrainPath™ (NICO Corporation, Indianapolis, IN). Herein, we present the design, development, and in vitro testing of an image-guided, focused ultrasound prototype designed for use in MIS procedures. This probe can ablate neuro-oncological lesions despite its small size. MATERIALS & METHODS Preliminary prototypes were iteratively designed, built, and tested. The final prototype consisted of three 8-mm-diameter therapeutic elements guided by an imaging probe. Probe functionality was validated on a series of tissue-mimicking phantoms. RESULTS Lesions were created in tissue-mimicking phantoms with average dimensions of 2.5 × 1.2 × 6.5 mm and 3.4 × 3.25 × 9.36 mm after 10- and 30-second sonification, respectively. 30 s sonification with 118 W power at 50% duty cycle generated a peak temperature of 68 °C. Each ablation was visualized in real time by the built-in imaging probe. CONCLUSION We developed and validated an ultrasound-guided focused ultrasound probe for use in MIS procedures. The dimensional constraints of the prototype were designed to reflect those of BrainPath trocars, which are MIS tools used to create atraumatic access to deep-seated brain pathologies.
Collapse
Affiliation(s)
- Micah Belzberg
- Department of Dermatology, Johns Hopkins University, Baltimore, MD, USA
| | - Smruti Mahapatra
- Department of Biomedical Engineering, Johns Hopkins University, Baltimore, MD, USA
| | | | | | | | | | - Nao J Gamo
- Maryland Development Center, Baltimore, MD, USA
| | | | - Nitish Thakor
- Department of Biomedical Engineering, Johns Hopkins University, Baltimore, MD, USA
| | - Youseph Yazdi
- Department of Biomedical Engineering, Johns Hopkins University, Baltimore, MD, USA
| | - Rajiv Iyer
- Department of Neurosurgery, Johns Hopkins University, Baltimore, MD, USA
| | - Betty Tyler
- Department of Neurosurgery, Johns Hopkins University, Baltimore, MD, USA
| | - Nicholas Theodore
- Department of Biomedical Engineering, Johns Hopkins University, Baltimore, MD, USA; Department of Neurosurgery, Johns Hopkins University, Baltimore, MD, USA
| | - Mark G Luciano
- Department of Biomedical Engineering, Johns Hopkins University, Baltimore, MD, USA; Department of Neurosurgery, Johns Hopkins University, Baltimore, MD, USA
| | - Henry Brem
- Department of Biomedical Engineering, Johns Hopkins University, Baltimore, MD, USA; Department of Neurosurgery, Johns Hopkins University, Baltimore, MD, USA
| | - Mari Groves
- Department of Neurosurgery, Johns Hopkins University, Baltimore, MD, USA
| | - Alan R Cohen
- Department of Neurosurgery, Johns Hopkins University, Baltimore, MD, USA
| | - Amir Manbachi
- Department of Biomedical Engineering, Johns Hopkins University, Baltimore, MD, USA; Department of Neurosurgery, Johns Hopkins University, Baltimore, MD, USA.
| |
Collapse
|
32
|
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: 192] [Impact Index Per Article: 48.0] [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.
Collapse
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.
| |
Collapse
|
33
|
Jones RM, Huang Y, Meng Y, Scantlebury N, Schwartz ML, Lipsman N, Hynynen K. Echo-Focusing in Transcranial Focused Ultrasound Thalamotomy for Essential Tremor: A Feasibility Study. Mov Disord 2020; 35:2327-2333. [PMID: 32815611 DOI: 10.1002/mds.28226] [Citation(s) in RCA: 21] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2020] [Revised: 06/30/2020] [Accepted: 07/02/2020] [Indexed: 11/06/2022] Open
Abstract
BACKGROUND Transcranial magnetic resonance-guided focused ultrasound (TcMRgFUS) systems currently employ computed tomography (CT)-based aberration corrections, which may provide suboptimal trans-skull focusing. OBJECTIVES The objective of this study was to evaluate a contrast agent microbubble imaging-based transcranial focusing method, echo-focusing (EF), during TcMRgFUS for essential tremor. METHODS A clinical trial of TcMRgFUS thalamotomy using EF for the treatment of essential tremor was conducted (NCT03935581; funded by InSightec [Tirat Carmel, Israel]). Patients (n = 12) were injected with Definity (Lantheus Medical Imaging, North Billerica, MA) microbubbles, and EF was performed using a research feature add-on to a commercial TcMRgFUS system (ExAblate Neuro, InSightec). Subablative thermal sonications carried out using (1) EF and (2) CT-based aberration corrections were compared via magnetic resonance thermometry, and the optimal focusing method for each patient was employed for TcMRgFUS thalamotomy. RESULTS EF aberration corrections provided increased sonication efficiency, decreased focal size, and equivalent targeting accuracy relative to CT-based focusing. EF aberration corrections were employed successfully for lesion formation in all 12 patients, 3 of whom had previously undergone unsuccessful TcMRgFUS thalamotomy via CT-based focusing. There were no adverse events related directly to the EF procedure. CONCLUSIONS EF is feasible and appears safe during TcMRgFUS thalamotomy for essential tremor and improves on the trans-skull focal quality provided by existing CT-based focusing methods. © 2020 International Parkinson and Movement Disorder Society.
Collapse
Affiliation(s)
- Ryan M Jones
- Physical Sciences Platform, Sunnybrook Research Institute, Toronto, Ontario, Canada
| | - Yuexi Huang
- Physical Sciences Platform, Sunnybrook Research Institute, Toronto, Ontario, Canada
| | - Ying Meng
- Division of Neurosurgery, Sunnybrook Health Sciences Centre, Toronto, Ontario, Canada.,Department of Surgery, University of Toronto, Toronto, Ontario, Canada
| | - Nadia Scantlebury
- Division of Neurosurgery, Sunnybrook Health Sciences Centre, Toronto, Ontario, Canada
| | - Michael L Schwartz
- Division of Neurosurgery, Sunnybrook Health Sciences Centre, Toronto, Ontario, Canada.,Department of Surgery, University of Toronto, Toronto, Ontario, Canada
| | - Nir Lipsman
- Division of Neurosurgery, Sunnybrook Health Sciences Centre, Toronto, Ontario, Canada.,Department of Surgery, 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.,Institute of Biomaterials and Biomedical Engineering, University of Toronto, Toronto, Ontario, Canada
| |
Collapse
|
34
|
Variations in targeting techniques of focused ultrasound for use in neuromodulation. Brain Stimul 2019; 12:1595-1596. [DOI: 10.1016/j.brs.2019.07.021] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2019] [Revised: 07/17/2019] [Accepted: 07/24/2019] [Indexed: 11/22/2022] Open
|
35
|
Chang KW, Park YS, Chang JW. Skull Factors Affecting Outcomes of Magnetic Resonance-Guided Focused Ultrasound for Patients with Essential Tremor. Yonsei Med J 2019; 60:768-773. [PMID: 31347332 PMCID: PMC6660436 DOI: 10.3349/ymj.2019.60.8.768] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/03/2019] [Revised: 05/03/2019] [Accepted: 05/29/2019] [Indexed: 11/27/2022] Open
Abstract
PURPOSE Magnetic resonance-guided focused ultrasound (MRgFUS) thalamotomy has become a standard treatment for medically intractable essential tremor (ET). Skull density ratio (SDR) and skull volume in patients with ET are currently considered useful indicators of the successful application of MRgFUS. We compared the clinical outcomes of MRgFUS thalamotomy with SDR above 0.4 and 0.45. We also described patterns of SDR and skull volume in Korean patients with ET who were eligible to be screened for MRgFUS. MATERIALS AND METHODS In screening 318 ET patients, we evaluated patterns of skull density and skull volume according to age and sex. Fifty patients with ET were treated with MRgFUS. We investigated the effects of SDR and skull volume on treatment parameters and the outcomes of ET. RESULTS The mean SDR of the 318 ET patients was 0.45±0.11, and that for skull volume was 315.74±40.95 cm³. The male patients had a higher SDR than female patients (p=0.047). Skull volume significantly decreased with aging. SDR and skull volume exhibited a linear negative relationship. Among therapeutic parameters, maximal temperature was positively related to SDR, while sonication number was not related to either SDR or skull volume. Tremor outcome was also not related to SDR or skull volume. CONCLUSION SDR varied widely from 0.11 to 0.73, and men had a higher SDR. Therapeutic parameters and clinical outcomes were not affected by SDR or skull volume.
Collapse
Affiliation(s)
- Kyung Won Chang
- Department of Neurosurgery, Brain Research Institute, Yonsei University College of Medicine, Seoul, Korea
| | - Yong Sook Park
- Department of Neurosurgery, Brain Research Institute, Chung-Ang University College of Medicine, Seoul, Korea
| | - Jin Woo Chang
- Department of Neurosurgery, Brain Research Institute, Yonsei University College of Medicine, Seoul, Korea.
| |
Collapse
|