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Giannakou M, Antoniou A, Damianou C. Preclinical robotic device for magnetic resonance imaging guided focussed ultrasound. Int J Med Robot 2023; 19:e2466. [PMID: 36169287 PMCID: PMC10078206 DOI: 10.1002/rcs.2466] [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: 05/24/2022] [Revised: 09/12/2022] [Accepted: 09/27/2022] [Indexed: 01/05/2023]
Abstract
BACKGROUND A robotic device featuring three motion axes was manufactured for preclinical research on focussed ultrasound (FUS). The device comprises a 2.75 MHz single element ultrasonic transducer and is guided by Magnetic Resonance Imaging (MRI). METHODS The compatibility of the device with the MRI was evaluated by estimating the influence on the signal-to-noise ratio (SNR). The efficacy of the transducer in generating ablative temperatures was evaluated in phantoms and excised porcine tissue. RESULTS System's activation in the MRI scanner reduced the SNR to an acceptable level without compromising the image quality. The transducer demonstrated efficient heating ability as proved by MR thermometry. Discrete and overlapping thermal lesions were inflicted in excised tissue. CONCLUSIONS The FUS system was proven effective for FUS thermal applications in the MRI setting. It can thus be used for multiple preclinical applications of the emerging MRI-guided FUS technology. The device can be scaled-up for human use with minor modifications.
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Affiliation(s)
| | - Anastasia Antoniou
- Department of Electrical Engineering, Computer Engineering, and Informatics, Cyprus University of Technology, Limassol, Cyprus
| | - Christakis Damianou
- Department of Electrical Engineering, Computer Engineering, and Informatics, Cyprus University of Technology, Limassol, Cyprus
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Duclos S, Golin A, Fox A, Chaudhary N, Camelo-Piragua S, Pandey A, Xu Z. Transcranial histotripsy parameter study in primary and metastatic murine brain tumor models. Int J Hyperthermia 2023; 40:2237218. [PMID: 37495214 PMCID: PMC10410615 DOI: 10.1080/02656736.2023.2237218] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2023] [Revised: 07/07/2023] [Accepted: 07/11/2023] [Indexed: 07/28/2023] Open
Abstract
OBJECTIVE This study investigated the effect of various histotripsy dosages on tumor cell kill and associated bleeding in two murine brain tumor models (glioma [Gl261] and lung metastasis [LL/2-Luc2]). METHODS AND MATERIALS GL261 or LL/2-Luc2 cells were cultured and implanted into the brains of C57BL/6 mice. Histotripsy (1-cycle pulses, 5 Hz PRF, 30 MPa-P) was performed using a 1 MHz transducer for five different dosages for each cell line: 5, 20 or 200 pulses per location (PPL) at a single treatment point, or 5 or 10-20 PPL at multiple treatment points. MRI, bioluminescence imaging and histology were used to assess tumor ablation and treatment effects within 4-6 h post-treatment. RESULTS All treatment groups resulted in a reduction of BLI intensity for the LL/2-Luc2 tumors, with significant signal reductions for the multi-point groups. The average pre-/post-treatment BLI flux (photons/s, ×108) for the different treatment groups were: 4.39/2.19 (5 PPL single-point), 5.49/1.80 (20 PPL single-point), 3.86/1.73 (200 PPL single-point), 2.44/1.11 (5 PPL multi-point) and 5.85/0.80 (10 PPL multi-point). MRI and H&E staining showed increased tumor damage and hemorrhagic effects with increasing histotripsy dose for both GL261 and LL/2-Luc2 tumors, but the increase in tumor damage was diminished beyond 10-20 PPL for single-point treatments and outweighed by increased hemorrhage. In general, hemorrhage was confined to be within 1 mm of the treatment boundary for all groups. CONCLUSIONS Our results suggest that a lower number of histotripsy pulses at fewer focal locations can achieve substantial tumor kill while minimizing hemorrhage.
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Affiliation(s)
- Sarah Duclos
- Department of Biomedical Engineering, University of Michigan, Ann Arbor, MI, USA
| | - Andrew Golin
- Department of Biomedical Engineering, University of Michigan, Ann Arbor, MI, USA
| | - Adam Fox
- Department of Biomedical Engineering, University of Michigan, Ann Arbor, MI, USA
- Department of Neurosurgery, University of Michigan, Ann Arbor, MI, USA
| | - Neeraj Chaudhary
- Department of Neurosurgery, University of Michigan, Ann Arbor, MI, USA
- Department of Radiology, University of Michigan, Ann Arbor, MI, USA
| | | | - Aditya Pandey
- Department of Neurosurgery, University of Michigan, Ann Arbor, MI, USA
| | - Zhen Xu
- Department of Biomedical Engineering, University of Michigan, Ann Arbor, MI, USA
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Hu Z, Chen S, Yang Y, Gong Y, Chen H. An Affordable and Easy-to-Use Focused Ultrasound Device for Noninvasive and High Precision Drug Delivery to the Mouse Brain. IEEE Trans Biomed Eng 2022; 69:2723-2732. [PMID: 35157574 PMCID: PMC9443669 DOI: 10.1109/tbme.2022.3150781] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
OBJECTIVE Focused ultrasound (FUS) combined with microbubble-mediated blood-brain barrier (BBB) opening (FUS-BBBO) is not only a promising technique for clinical applications but also a powerful tool for preclinical research. However, existing FUS devices for preclinical research are expensive, bulky, and lack the precision needed for small animal research, which limits the broad adoption of this promising technique by the research community. Our objective was to design and fabricate an affordable, easy-to-use, high-precision FUS device for small animal research. METHODS We designed and fabricated in-house mini-FUS transducers (∼$80 each in material cost) with three frequencies (1.5, 3.0, and 6.0 MHz) and integrated them with a stereotactic frame for precise mouse brain targeting using established stereotactic procedures. The BBB opening volume by FUS at different acoustic pressures (0.20-0.57 MPa) was quantified using T1-weighted contrast-enhanced magnetic resonance imaging of gadolinium leakage and fluorescence imaging of Evans blue extravasation. RESULTS The targeting accuracy of the device as measured by the offset between the desired target location and the centroid of BBBO was 0.63 ± 0.19 mm. The spatial precision of the device in targeting individual brain structures was improved by the use of higher frequency FUS transducers. The BBB opening volume had high linear correlations with the cavitation index (defined by the ratio between acoustic pressure and frequency) and mechanical index (defined by the ratio between acoustic pressure and the square root of frequency). The correlation coefficient of the cavitation index was slightly higher than that of the mechanical index. CONCLUSION This study demonstrated that spatially accurate and precise BBB opening was achievable using an affordable and easy-to-use FUS device. The BBB opening volume was tunable by modulating the cavitation index. This device is expected to decrease the barriers to the adoption of the FUS-BBBO technique by the broad research community.
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Rahimi S, Jones RM, Hynynen K. A High-Frequency Phased Array System for Transcranial Ultrasound Delivery in Small Animals. IEEE TRANSACTIONS ON ULTRASONICS, FERROELECTRICS, AND FREQUENCY CONTROL 2021; 68:127-135. [PMID: 32746231 PMCID: PMC7863589 DOI: 10.1109/tuffc.2020.3012868] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
Existing systems for applying transcranial focused ultrasound (FUS) in small animals produce large focal volumes relative to the size of cerebral structures available for interrogation. The use of high ultrasonic frequencies can improve targeting specificity; however, the aberrations induced by rodent calvaria at megahertz frequencies severely distort the acoustic fields produced by single-element focused transducers. Here, we present the design, fabrication, and characterization of a high-frequency phased array system for transcranial FUS delivery in small animals. A transducer array was constructed by micromachining a spherically curved PZT-5H bowl (diameter = 25 mm, radius of curvature = 20 mm, fundamental frequency = 3.3 MHz) into 64 independent elements of equal surface area. The acoustic field generated by the phased array was measured at various target locations using a calibrated fiber-optic hydrophone, both in free-field conditions as well as through ex vivo rat skullcaps with and without hydrophone-assisted phase aberration corrections. Large field-of-view acoustic field simulations were carried out to investigate potential grating lobe formation. The focal beam size obtained when targeting the array's geometric focus was [Formula: see text] mm in water. The array can steer the FUS beam electronically over cylindrical volumes of 4.5 mm in diameter and 6 mm in height without introducing grating lobes. Insertion of a rat skullcap resulted in substantial distortion of the acoustic field ( [Formula: see text]% [Formula: see text]); however, phase corrections restored partial focal quality ( [Formula: see text]% [Formula: see text]). Using phase corrections, the array is capable of generating a trans-rat skull peak negative focal pressure of up to ~2.0 MPa, which is sufficient for microbubble-mediated blood-brain barrier permeabilization at this frequency.
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Jung B, Huh H, Lee EH, Han M, Park J. An advanced focused ultrasound protocol improves the blood-brain barrier permeability and doxorubicin delivery into the rat brain. J Control Release 2019; 315:55-64. [PMID: 31669208 DOI: 10.1016/j.jconrel.2019.10.044] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2019] [Revised: 10/17/2019] [Accepted: 10/22/2019] [Indexed: 12/12/2022]
Abstract
Despite the recent development of a focused ultrasound (FUS) technique for disrupting the blood-brain barrier (BBB) and enabling the delivery of drugs into the targeted brain region, different sonication protocols have not been fully explored. In this study, we suggest a simple and cost-effective protocol that improves the BBB permeability and drug delivery without damaging the tissue. In this protocol, called "FUS+BBBD protocol", an additional FUS stimulation without microbubbles ("FUS protocol"; 0.5, 1.0, or 2.0MPa acoustic pressure, 10ms tone burst, 1Hz pulse repetition frequency, 120s total duration) is applied prior to the conventional BBB disruption with microbubbles ("BBBD protocol"; 0.6∼0.72MPa acoustic pressure, 10ms tone burst, 1Hz pulse repetition frequency, 120s total duration). With the "FUS+BBBD protocol", the magnetic resonance signal intensity and doxorubicin delivery at the targeted brain region were increased by 1.59 and 1.75 times at an FUS intensity of 1.0MPa, respectively, compared to the conventional BBBD. Other conditions also increase the drug delivery, but the increase was smaller than that at 1.0MPa (1.15 times for 0.5MPa and 1.60 times for 2.0MPa). The H&E histopathological analysis of the sonicated brain region using the proposed "FUS+BBBD protocol" showed no significant brain tissue damage at a FUS intensity of 0.5 and 1.0MPa. However, region cavities due to the damage were observed after an FUS intensity of 2.0MPa. These results suggest that the 1.0MPa "FUS+BBBD protocol" increases the BBB permeability and enhances the drug delivery efficiency without noticeable brain tissue damage, compared with the conventional BBBD. Although further studies are needed to determine the underlying mechanism of this effect, drugs that have been reported to be effective in the treatment of brain disease but had limited use due to severe systemic side effects will benefit from the enhanced drug delivery of "FUS+BBBD protocol". Furthermore, the suggested protocol may facilitate the development of new strategies in clinical trials to treat brain disorders with improved drug delivery and safety.
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Affiliation(s)
- Byeongjin Jung
- Medical Device Development Center, Daegu-Gyeongbuk Medical Innovation Foundation, 80 Cheombok-ro, Dong-gu, Daegu, 41061, Republic of Korea
| | - Hyungkyu Huh
- Medical Device Development Center, Daegu-Gyeongbuk Medical Innovation Foundation, 80 Cheombok-ro, Dong-gu, Daegu, 41061, Republic of Korea
| | - Eun-Hee Lee
- Medical Device Development Center, Daegu-Gyeongbuk Medical Innovation Foundation, 80 Cheombok-ro, Dong-gu, Daegu, 41061, Republic of Korea
| | - Mun Han
- Medical Device Development Center, Daegu-Gyeongbuk Medical Innovation Foundation, 80 Cheombok-ro, Dong-gu, Daegu, 41061, Republic of Korea
| | - Juyoung Park
- Medical Device Development Center, Daegu-Gyeongbuk Medical Innovation Foundation, 80 Cheombok-ro, Dong-gu, Daegu, 41061, Republic of Korea.
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Gerstenmayer M, Fellah B, Magnin R, Selingue E, Larrat B. Acoustic Transmission Factor through the Rat Skull as a Function of Body Mass, Frequency and Position. ULTRASOUND IN MEDICINE & BIOLOGY 2018; 44:2336-2344. [PMID: 30076032 DOI: 10.1016/j.ultrasmedbio.2018.06.005] [Citation(s) in RCA: 26] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/11/2017] [Revised: 06/07/2018] [Accepted: 06/08/2018] [Indexed: 05/26/2023]
Abstract
In many transcranial ultrasound studies on rats, the transmission factor is assumed to be independent of animal weight and losses resulting from non-normal incidence angles of the beam are not accounted for. In this study, we measured acoustic transmission factors through 13 excised skulls of male Sprague-Dawley rats weighing between 90 and 520g, at different positions on each skull and at 1, 1.25, 1.5, 1.75 and 2MHz. Our results revealed that insertion loss through rat skull increases linearly with both body mass and frequency and strongly depends on the position, decreasing from the front to the back and from the midline to the lateral sides. Skull thickness also scales linearly with body mass. Reflection explains the main part of the insertion loss compared with attenuation and aberration. These data are helpful in predicting the acoustic pressure at the focus in the brain.
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Affiliation(s)
- Matthieu Gerstenmayer
- NeuroSpin, Institut pour les sciences du vivant Frédéric Joliot, Direction de la Recherche Fondamentale, Commissariat à l'Energie Atomique, Université Paris Saclay, Gif sur Yvette, France
| | - Benjamin Fellah
- NeuroSpin, Institut pour les sciences du vivant Frédéric Joliot, Direction de la Recherche Fondamentale, Commissariat à l'Energie Atomique, Université Paris Saclay, Gif sur Yvette, France
| | - Rémi Magnin
- NeuroSpin, Institut pour les sciences du vivant Frédéric Joliot, Direction de la Recherche Fondamentale, Commissariat à l'Energie Atomique, Université Paris Saclay, Gif sur Yvette, France
| | - Erwan Selingue
- NeuroSpin, Institut pour les sciences du vivant Frédéric Joliot, Direction de la Recherche Fondamentale, Commissariat à l'Energie Atomique, Université Paris Saclay, Gif sur Yvette, France
| | - Benoit Larrat
- NeuroSpin, Institut pour les sciences du vivant Frédéric Joliot, Direction de la Recherche Fondamentale, Commissariat à l'Energie Atomique, Université Paris Saclay, Gif sur Yvette, France.
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Maimbourg G, Houdouin A, Santin M, Lehericy S, Tanter M, Aubry JF. Inside/outside the brain binary cavitation localization based on the lowpass filter effect of the skull on the harmonic content: a proof of concept study. Phys Med Biol 2018; 63:135012. [PMID: 29864024 DOI: 10.1088/1361-6560/aaca21] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Abstract
Cavitation activity induced by ultrasound may occur during high intensity focused ultrasound (HIFU) treatment, due to bubble nucleation under high peak negative pressure, and during blood-brain-barrier (BBB) disruption, due to injected ultrasound contrast agents (UCAs). Such microbubble activity has to be monitored to assess the safety and efficiency of ultrasonic brain treatments. In this study, we aim at assessing whether cavitation occurs within cerebral tissue by binary discriminating cavitation activity originating from the inside or the outside of the skull. The results were obtained from both in vitro experiments mimicking BBB opening, by using UCA flow, and in vitro thermal necrosis in calf brain samples. The sonication was applied using a 1 MHz focused transducer and the acoustic response of the microbubbles was recorded with a wideband passive cavitation detector. The spectral content of the recorded signal was used to localize microbubble activity. Since the skull acts as a low pass filter, the ratio of high harmonics to low harmonics is lower for cavitation events located inside the skull compared to events outside the skull. Experiments showed that the ratio of the 5/2 ultraharmonic to the 1/2 subharmonic for binary localization cavitation activity achieves 100% sensitivity and specificity for both monkey and human skulls. The harmonic ratio of the fourth to the second harmonic provided 100% sensitivity and 96% and 46% specificity on a non-human primate for thermal necrosis and BBB opening, respectively. Nonetheless, the harmonic ratio remains promising for human applications, as the experiments showed 100% sensitivity and 100% specificity for both thermal necrosis and BBB opening through the human skull. The study requires further validation on a larger number of skull samples.
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Affiliation(s)
- Guillaume Maimbourg
- Institut Langevin, ESPCI Paris, CNRS UMR7587, INSERM U 979, F-75012, PSL Research University, Paris, France. Université Paris Diderot, Sorbonne Paris Cité, F-75013, Paris, France
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Shen WB, Anastasiadis P, Nguyen B, Yarnell D, Yarowsky PJ, Frenkel V, Fishman PS. Magnetic Enhancement of Stem Cell-Targeted Delivery into the Brain Following MR-Guided Focused Ultrasound for Opening the Blood-Brain Barrier. Cell Transplant 2018; 26:1235-1246. [PMID: 28933214 PMCID: PMC5657739 DOI: 10.1177/0963689717715824] [Citation(s) in RCA: 41] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
Focused ultrasound (FUS)-mediated blood–brain barrier disruption (BBBD) can enable even large therapeutics such as stem cells to enter the brain from the bloodstream. However, the efficiency is relatively low. Our previous study showed that human neural progenitor cells (hNPCs) loaded with superparamagnetic iron oxide nanoparticles (SPIONs) in culture were attracted by an external magnetic field. In vivo, enhanced brain retention was observed near a magnet mounted on the skull in a rat model of traumatic brain injury, where BBBD also occurs. The goal of the current study was to determine whether magnetic attraction of SPION-loaded hNPCs would also enhance their retention in the brain after FUS-mediated BBBD. A small animal magnetic resonance imaging (MRI)-guided FUS system operating at 1.5 MHz was used to treat rats (∼120 g) without tissue damage or hemorrhage. Evidence of successful BBBD was validated with both radiologic enhancement of gadolinium on postsonication TI MRI and whole brain section visualization of Evans blue dye. The procedure was then combined with the application of a powerful magnet to the head directly after intravenous injection of the hNPCs. Validation of cells within the brain was performed by staining with Perls’ Prussian blue for iron and by immunohistochemistry with a human-specific antigen. By injecting equal numbers of iron oxide (SPIONs) and noniron oxide nanoparticles–loaded hNPCs, each labeled with a different fluorophore, we found significantly greater numbers of SPIONs-loaded cells retained in the brain at the site of BBBD as compared to noniron loaded cells. This result was most pronounced in regions of the brain closest to the skull (dorsal cortex) in proximity to the magnet surface. A more powerful magnet and a Halbach magnetic array resulted in more effective retention of SPION-labeled cells in even deeper brain regions such as the striatum and ventral cortex. There, up to 90% of hNPCs observed contained SPIONs compared to 60% to 70% with the less powerful magnet. Fewer cells were observed at 24 h posttreatment compared to 2 h (primarily in the dorsal cortex). These results demonstrate that magnetic attraction can substantially enhance the retention of stem cells after FUS-mediated BBBD. This procedure could provide a safer and less invasive approach for delivering stem cells to the brain, compared to direct intracranial injections, substantially reducing the risk of bleeding and infection.
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Affiliation(s)
- Wei-Bin Shen
- 1 Department of Pharmacology, University of Maryland School of Medicine, Baltimore, MD, USA
| | - Pavlos Anastasiadis
- 2 Department of Diagnostic Radiology and Nuclear Medicine, University of Maryland School of Medicine, Baltimore, MD, USA
| | - Ben Nguyen
- 2 Department of Diagnostic Radiology and Nuclear Medicine, University of Maryland School of Medicine, Baltimore, MD, USA
| | - Deborah Yarnell
- 3 Neurology Service, VA Maryland Healthcare System, Baltimore, MD, USA
| | - Paul J Yarowsky
- 1 Department of Pharmacology, University of Maryland School of Medicine, Baltimore, MD, USA.,4 Research Service, VA Maryland Healthcare System, Baltimore, MD, USA
| | - Victor Frenkel
- 2 Department of Diagnostic Radiology and Nuclear Medicine, University of Maryland School of Medicine, Baltimore, MD, USA.,5 Marlene and Stewart Greenebaum Comprehensive Cancer Center, University of Maryland School of Medicine, Baltimore, MD, USA
| | - Paul S Fishman
- 3 Neurology Service, VA Maryland Healthcare System, Baltimore, MD, USA.,6 Department of Neurology, University of Maryland School of Medicine, Baltimore, MD, USA
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Constans C, Mateo P, Tanter M, Aubry JF. Potential impact of thermal effects during ultrasonic neurostimulation: retrospective numerical estimation of temperature elevation in seven rodent setups. ACTA ACUST UNITED AC 2018; 63:025003. [DOI: 10.1088/1361-6560/aaa15c] [Citation(s) in RCA: 54] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
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Gutierrez MI, Penilla EH, Leija L, Vera A, Garay JE, Aguilar G. Novel Cranial Implants of Yttria-Stabilized Zirconia as Acoustic Windows for Ultrasonic Brain Therapy. Adv Healthc Mater 2017; 6. [PMID: 28766896 DOI: 10.1002/adhm.201700214] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2017] [Revised: 06/14/2017] [Indexed: 12/22/2022]
Abstract
Therapeutic ultrasound can induce changes in tissues by means of thermal and nonthermal effects. It is proposed for treatment of some brain pathologies such as Alzheimer's, Parkinson's, Huntington's diseases, and cancer. However, cranium highly absorbs ultrasound reducing transmission efficiency. There are clinical applications of transcranial focused ultrasound and implantable ultrasound transducers proposed to address this problem. In this paper, biocompatible materials are proposed for replacing part of the cranium (cranial implants) based on low porosity polycrystalline 8 mol% yttria-stabilized-zirconia (8YSZ) ceramics as acoustic windows for brain therapy. In order to assess the viability of 8YSZ implants to effectively transmit ultrasound, various 8YSZ ceramics with different porosity are tested; their acoustic properties are measured; and the results are validated using finite element models simulating wave propagation to brain tissue through 8YSZ windows. The ultrasound attenuation is found to be linearly dependent on ceramics' porosity. Results for the nearly pore-free case indicate that 8YSZ is highly effective in transmitting ultrasound, with overall maximum transmission efficiency of ≈81%, compared to near total absorption of cranial bone. These results suggest that 8YSZ polycrystals could be suitable acoustic windows for ultrasound brain therapy at 1 MHz.
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Affiliation(s)
- Mario I. Gutierrez
- CONACYT—Instituto Nacional de Rehabilitación Subdirección de Investigación Tecnológica División de Investigación en Ingenieria Medica (DIIM) Mexico City 14389 Mexico
| | - Elias H. Penilla
- Mechanical and Aerospace Engineering University of California San Diego San Diego CA 92161 USA
| | - Lorenzo Leija
- Department of Electrical Engineering, Bioelectronics Centro de Investigación y de Estudios Avanzados del IPN CINVESTAV‐IPN Mexico City 07360 Mexico
| | - Arturo Vera
- Department of Electrical Engineering, Bioelectronics Centro de Investigación y de Estudios Avanzados del IPN CINVESTAV‐IPN Mexico City 07360 Mexico
| | - Javier E. Garay
- Mechanical and Aerospace Engineering University of California San Diego San Diego CA 92161 USA
| | - Guillermo Aguilar
- Department of Mechanical Engineering University of California Riverside Riverside CA 92521 USA
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Ellens NPK, Partanen A. Preclinical MRI-Guided Focused Ultrasound: A Review of Systems and Current Practices. IEEE TRANSACTIONS ON ULTRASONICS, FERROELECTRICS, AND FREQUENCY CONTROL 2017; 64:291-305. [PMID: 27662675 DOI: 10.1109/tuffc.2016.2609238] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
Effective preclinical research is a vital component in the development of MRI-guided focused ultrasound (MRgFUS) and its translation to clinic. In this review, we seek to outline the challenges at hand for effective preclinical research, survey different solutions, and underline best practices. Furthermore, we summarize efforts to build and characterize dedicated preclinical MRgFUS equipment, including lab prototypes and available commercial products. Finally, we discuss constraints and considerations specific to using clinical MRgFUS equipment in preclinical research. Specifically, we examine additional hardware that has been used to adapt clinical MRgFUS equipment to better position, constrain, and image preclinical subjects, as well as software solutions that have been used to extend the potential and capabilities of clinical devices.
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12
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Magnin R, Rabusseau F, Salabartan F, Mériaux S, Aubry JF, Le Bihan D, Dumont E, Larrat B. Magnetic resonance-guided motorized transcranial ultrasound system for blood-brain barrier permeabilization along arbitrary trajectories in rodents. J Ther Ultrasound 2015; 3:22. [PMID: 26705473 PMCID: PMC4690289 DOI: 10.1186/s40349-015-0044-5] [Citation(s) in RCA: 41] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2015] [Accepted: 12/18/2015] [Indexed: 11/17/2022] Open
Abstract
BACKGROUND Focused ultrasound combined with microbubble injection is capable of locally and transiently enhancing the permeability of the blood-brain barrier (BBB). Magnetic resonance imaging (MRI) guidance enables to plan, monitor, and characterize the BBB disruption. Being able to precisely and remotely control the permeabilization location is of great interest to perform reproducible drug delivery protocols. METHODS In this study, we developed an MR-guided motorized focused ultrasound (FUS) system allowing the transducer displacement within preclinical MRI scanners, coupled with real-time transfer and reconstruction of MRI images, to help ultrasound guidance. Capabilities of this new device to deliver large molecules to the brain on either single locations or along arbitrary trajectories were characterized in vivo on healthy rats and mice using 1.5 MHz ultrasound sonications combined with microbubble injection. The efficacy of BBB permeabilization was assessed by injecting a gadolinium-based MR contrast agent that does not cross the intact BBB. RESULTS The compact motorized FUS system developed in this work fits into the 9-cm inner diameter of the gradient insert installed on our 7-T preclinical MRI scanners. MR images acquired after contrast agent injection confirmed that this device can be used to enhance BBB permeability along remotely controlled spatial trajectories of the FUS beam in both rats and mice. The two-axis motor stage enables reaching any region of interest in the rodent brain. The positioning error when targeting the same anatomical location on different animals was estimated to be smaller than 0.5 mm. Finally, this device was demonstrated to be useful for testing BBB opening at various acoustic pressures (0.2, 0.4, 0.7, and 0.9 MPa) in the same animal and during one single ultrasound session. CONCLUSIONS Our system offers the unique possibility to move the transducer within a high magnetic field preclinical MRI scanner, thus enabling the delivery of large molecules to virtually any rodent brain area in a non-invasive manner. It results in time-saving and reproducibility and could be used to either deliver drugs over large parts of the brain or test different acoustic conditions on the same animal during the same session, therefore reducing physiological variability.
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Affiliation(s)
- Rémi Magnin
- />UNIRS, Neurospin, I2BM, Direction des Sciences du Vivant, Commissariat à l’Energie Atomique et aux Energies Alternatives, Bâtiment 145, 91191 Gif sur Yvette, France
- />Image Guided Therapy, 4 allée du doyen Brus, 33600 Pessac, France
| | - Fabien Rabusseau
- />Image Guided Therapy, 4 allée du doyen Brus, 33600 Pessac, France
| | | | - Sébastien Mériaux
- />UNIRS, Neurospin, I2BM, Direction des Sciences du Vivant, Commissariat à l’Energie Atomique et aux Energies Alternatives, Bâtiment 145, 91191 Gif sur Yvette, France
| | - Jean-François Aubry
- />CNRS UMR 7587, INSERM U979, ESPCI ParisTech, Institut Langevin Ondes et Images, 1 rue Jussieu, 75005 Paris, France
| | - Denis Le Bihan
- />UNIRS, Neurospin, I2BM, Direction des Sciences du Vivant, Commissariat à l’Energie Atomique et aux Energies Alternatives, Bâtiment 145, 91191 Gif sur Yvette, France
| | - Erik Dumont
- />Image Guided Therapy, 4 allée du doyen Brus, 33600 Pessac, France
| | - Benoit Larrat
- />UNIRS, Neurospin, I2BM, Direction des Sciences du Vivant, Commissariat à l’Energie Atomique et aux Energies Alternatives, Bâtiment 145, 91191 Gif sur Yvette, France
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13
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Eames MDC, Farnum M, Khaled M, Elias WJ, Hananel A, Snell JW, Kassell NF, Aubry JF. Head phantoms for transcranial focused ultrasound. Med Phys 2015; 42:1518-27. [PMID: 25832042 DOI: 10.1118/1.4907959] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023] Open
Abstract
PURPOSE In the ongoing endeavor of fine-tuning, the clinical application of transcranial MR-guided focused ultrasound (tcMRgFUS), ex-vivo studies wlkiith whole human skulls are of great use in improving the underlying technology guiding the accurate and precise thermal ablation of clinically relevant targets in the human skull. Described here are the designs, methods for fabrication, and notes on utility of three different ultrasound phantoms to be used for brain focused ultrasound research. METHODS Three different models of phantoms are developed and tested to be accurate, repeatable experimental options to provide means to further this research. The three models are a cadaver, a gel-filled skull, and a head mold containing a skull and filled with gel that mimics the brain and the skin. Each was positioned in a clinical tcMRgFUS system and sonicated at 1100 W (acoustic) for 12 s at different locations. Maximum temperature rise as measured by MR thermometry was recorded and compared against clinical data for a similar neurosurgical target. Results are presented as heating efficiency in units (°C/kW/s) for direct comparison to available clinical data. The procedure for casting thermal phantom material is presented. The utility of each phantom model is discussed in the context of various tcMRgFUS research areas. RESULTS The cadaveric phantom model, gel-filled skull model, and full head phantom model had heating efficiencies of 5.3, 4.0, and 3.9 °C/(kW/s), respectively, compared to a sample clinical heating efficiency of 2.6 °C/(kW/s). In the seven research categories considered, the cadaveric phantom model was the most versatile, though less practical compared to the ex-vivo skull-based phantoms. CONCLUSIONS Casting thermal phantom material was shown to be an effective way to prepare tissue-mimicking material for the phantoms presented. The phantom models presented are all useful in tcMRgFUS research, though some are better suited to a limited subset of applications depending on the researchers needs.
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Affiliation(s)
| | - Mercy Farnum
- Focused Ultrasound Foundation, Charlottesville, Virginia 22903
| | - Mohamad Khaled
- Department of Neurosurgery, University of Virginia, Charlottesville, Virginia 22908
| | - W Jeff Elias
- Department of Neurosurgery, University of Virginia, Charlottesville, Virginia 22908
| | - Arik Hananel
- Focused Ultrasound Foundation, Charlottesville, Virginia 22903 and Department of Radiation Oncology, University of Virginia, Charlottesville, Virginia 22908
| | - John W Snell
- Focused Ultrasound Foundation, Charlottesville, Virginia 22903 and Department of Neurosurgery, University of Virginia, Charlottesville, Virginia 22908
| | - Neal F Kassell
- Focused Ultrasound Foundation, Charlottesville, Virginia 22903 and Department of Neurosurgery, University of Virginia, Charlottesville, Virginia 22908
| | - Jean-Francois Aubry
- Department of Radiation Oncology, University of Virginia, Charlottesville, Virginia 22908 and Institut Langevin, ESPCI ParisTech, CNRS UMR 7587, INSERM U979, Paris 75005, France
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14
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Chao YT, Hsu CJ, Yu YL, Yen JY, Ho MC, Chen YY, Chang HC, Lian FL. A novel sound-blocking structure based on the muffler principle for rib-sparing transcostal high-intensity focused ultrasound treatment. Int J Hyperthermia 2015; 31:507-27. [DOI: 10.3109/02656736.2015.1028483] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023] Open
Affiliation(s)
- Yu-Tin Chao
- Department of Mechanical Engineering, National Taiwan University, Taipei,
| | - Che-Jung Hsu
- Department of Mechanical Engineering, National Taiwan University, Taipei,
| | - Ya-Lin Yu
- Department of Mechanical Engineering, National Taiwan University, Taipei,
| | - Jia-Yush Yen
- Department of Mechanical Engineering, National Taiwan University, Taipei,
| | - Ming-Chih Ho
- Department of Surgery, National Taiwan University Hospital and College of Medicine, Taipei, and
| | - Yung-Yaw Chen
- Department of Electrical Engineering, National Taiwan University, Taipei, Taiwan, Republic of China
| | - Hung-Cheng Chang
- Department of Mechanical Engineering, National Taiwan University, Taipei,
| | - Feng-Li Lian
- Department of Electrical Engineering, National Taiwan University, Taipei, Taiwan, Republic of China
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15
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Xu Z, Carlson C, Snell J, Eames M, Hananel A, Lopes MB, Raghavan P, Lee CC, Yen CP, Schlesinger D, Kassell NF, Aubry JF, Sheehan J. Intracranial inertial cavitation threshold and thermal ablation lesion creation using MRI-guided 220-kHz focused ultrasound surgery: preclinical investigation. J Neurosurg 2015; 122:152-61. [PMID: 25380106 DOI: 10.3171/2014.9.jns14541] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
OBJECT In biological tissues, it is known that the creation of gas bubbles (cavitation) during ultrasound exposure is more likely to occur at lower rather than higher frequencies. Upon collapsing, such bubbles can induce hemorrhage. Thus, acoustic inertial cavitation secondary to a 220-kHz MRI-guided focused ultrasound (MRgFUS) surgery is a serious safety issue, and animal studies are mandatory for laying the groundwork for the use of low-frequency systems in future clinical trials. The authors investigate here the in vivo potential thresholds of MRgFUS-induced inertial cavitation and MRgFUS-induced thermal coagulation using MRI, acoustic spectroscopy, and histology. METHODS Ten female piglets that had undergone a craniectomy were sonicated using a 220-kHz transcranial MRgFUS system over an acoustic energy range of 5600-14,000 J. For each piglet, a long-duration sonication (40-second duration) was performed on the right thalamus, and a short sonication (20-second duration) was performed on the left thalamus. An acoustic power range of 140-300 W was used for long-duration sonications and 300-700 W for short-duration sonications. Signals collected by 2 passive cavitation detectors were stored in memory during each sonication, and any subsequent cavitation activity was integrated within the bandwidth of the detectors. Real-time 2D MR thermometry was performed during the sonications. T1-weighted, T2-weighted, gradient-recalled echo, and diffusion-weighted imaging MRI was performed after treatment to assess the lesions. The piglets were killed immediately after the last series of posttreatment MR images were obtained. Their brains were harvested, and histological examinations were then performed to further evaluate the lesions. RESULTS Two types of lesions were induced: thermal ablation lesions, as evidenced by an acute ischemic infarction on MRI and histology, and hemorrhagic lesions, associated with inertial cavitation. Passive cavitation signals exhibited 3 main patterns identified as follows: no cavitation, stable cavitation, and inertial cavitation. Low-power and longer sonications induced only thermal lesions, with a peak temperature threshold for lesioning of 53°C. Hemorrhagic lesions occurred only with high-power and shorter sonications. The sizes of the hemorrhages measured on macroscopic histological examinations correlated with the intensity of the cavitation activity (R2 = 0.74). The acoustic cavitation activity detected by the passive cavitation detectors exhibited a threshold of 0.09 V·Hz for the occurrence of hemorrhages. CONCLUSIONS This work demonstrates that 220-kHz ultrasound is capable of inducing a thermal lesion in the brain of living swines without hemorrhage. Although the same acoustic energy can induce either a hemorrhage or a thermal lesion, it seems that low-power, long-duration sonication is less likely to cause hemorrhage and may be safer. Although further study is needed to decrease the likelihood of ischemic infarction associated with the 220-kHz ultrasound, the threshold established in this work may allow for the detection and prevention of deleterious cavitations.
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16
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Zhang Y, Aubry JF, Zhang J, Wang Y, Roy J, Mata JF, Miller W, Dumont E, Xie M, Lee K, Zuo Z, Wintermark M. Defining the optimal age for focal lesioning in a rat model of transcranial HIFU. ULTRASOUND IN MEDICINE & BIOLOGY 2015; 41:449-55. [PMID: 25542495 DOI: 10.1016/j.ultrasmedbio.2014.09.029] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/10/2014] [Revised: 09/22/2014] [Accepted: 09/22/2014] [Indexed: 05/17/2023]
Abstract
This study aimed at determining the optimal age group for high-intensity focused ultrasound (HIFU) experiments for producing lesions in rats. Younger rats have thinner skulls, allowing for the acoustic waves to propagate easily through the skull without causing burns of the skin and brain surface. Younger rats however, have a smaller brain that can make HIFU focusing in the brain parenchyma challenging because of the focus size. In this study, we conducted transcranial HIFU sonications in rat pups of different ages (from 9 to 43 d) with a 1.5MHz MR compatible transducer. The electric power was selected to always reach a target temperature of at least 50°C in the parenchyma. The thickness of the skull and of the brain parenchyma was measured using T2-weighted MR imaging. Results showed that the thickness of the brain parenchyma increased quickly from P9 to P12, reaching 8.5 mm at P16, and then increasing gradually along with age. The skull thickness increased gradually from P9 to P26, and then more quickly after P30. The ratio between brain parenchyma thickness and skull thickness decreased gradually with age. For the pups at 30 d, the temperature in the brain tissue adjacent to the skull increased to 48.9°C, and those from the rodents older than 33 d reached 60°C or higher, which can produce undesired irreversible damage in this location. We conclude that young rats aged 16-26 d are optimal for experiments producing transcranial HIFU lesions in rats with an intact skull.
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Affiliation(s)
- Yanrong Zhang
- Department of Ultrasound, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei, China; Neuroradiology Division, Department of Radiology, University of Virginia, Charlottesville, VA, USA
| | - Jean-François Aubry
- Department of Radiation Oncology, University of Virginia, Charlottesville, VA, USA; ESPCI ParisTech, PSL Research University, Institut Langevin, Paris, France; CNRS, Institut Langevin, Paris, France; INSERM, Institut Langevin, Paris, France
| | - Junfeng Zhang
- Department of Anesthesiology, University of Virginia, Charlottesville, VA, USA; Department of Anesthesiology, Shanghai Sixth Hospital, Shanghai Jiaotong University, Shanghai, China
| | - Yi Wang
- Departments of Neuroscience and Neurologic Surgery, University of Virginia, Charlottesville, VA, USA
| | - Jack Roy
- Department of Radiology, University of Virginia, Charlottesville, VA, USA
| | - Jaime F Mata
- Department of Radiology, University of Virginia, Charlottesville, VA, USA
| | - Wilson Miller
- Department of Radiology, University of Virginia, Charlottesville, VA, USA
| | | | - Mingxing Xie
- Department of Ultrasound, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei, China
| | - Kevin Lee
- Departments of Neuroscience and Neurologic Surgery, University of Virginia, Charlottesville, VA, USA
| | - Zhiyi Zuo
- Department of Anesthesiology, University of Virginia, Charlottesville, VA, USA
| | - Max Wintermark
- Neuroradiology Division, Department of Radiology, University of Virginia, Charlottesville, VA, USA.
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17
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Chang JW, Min BK, Kim BS, Chang WS, Lee YH. Neurophysiologic correlates of sonication treatment in patients with essential tremor. ULTRASOUND IN MEDICINE & BIOLOGY 2015; 41:124-131. [PMID: 25438838 DOI: 10.1016/j.ultrasmedbio.2014.08.008] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/25/2013] [Revised: 07/23/2014] [Accepted: 08/12/2014] [Indexed: 06/04/2023]
Abstract
Transcranial magnetic resonance imaging-guided high-intensity focused ultrasound (MRgHIFU) is gaining attention as a potent substitute for surgical intervention in the treatment of neurologic disorders. To discern the neurophysiologic correlates of its therapeutic effects, we applied MRgHIFU to an intractable neurologic disorder, essential tremor, while measuring magnetoencephalogram mu rhythms from the motor cortex. Focused ultrasound sonication destroyed tissues by focusing a high-energy beam on the ventralis intermedius nucleus of the thalamus. The post-treatment effectiveness was also evaluated using the clinical rating scale for tremors. Thalamic MRgHIFU had substantial therapeutic effects on patients, based on MRgHIFU-mediated improvements in movement control and significant changes in brain mu rhythms. Ultrasonic thalamotomy may reduce hyper-excitable activity in the motor cortex, resulting in normalized behavioral activity after sonication treatment. Thus, non-invasive and spatially accurate MRgHIFU technology can serve as a potent therapeutic tool with broad clinical applications.
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Affiliation(s)
- Jin Woo Chang
- Department of Neurosurgery, Yonsei University College of Medicine, Seoul, Korea
| | - Byoung-Kyong Min
- Department of Brain and Cognitive Engineering, Korea University, Seoul, Korea.
| | - Bong-Soo Kim
- Department of Neurosurgery, Yonsei University College of Medicine, Seoul, Korea
| | - Won Seok Chang
- Department of Neurosurgery, Yonsei University College of Medicine, Seoul, Korea
| | - Yong-Ho Lee
- Korea Research Institute of Standards and Science, Daejeon, Korea
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