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Haqshenas SR, Gélat P, van 't Wout E, Betcke T, Saffari N. A fast full-wave solver for calculating ultrasound propagation in the body. ULTRASONICS 2021; 110:106240. [PMID: 32950757 DOI: 10.1016/j.ultras.2020.106240] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/25/2020] [Revised: 08/20/2020] [Accepted: 08/25/2020] [Indexed: 05/23/2023]
Abstract
Therapeutic ultrasound is a promising non-invasive method for inducing various beneficial biological effects in the human body. In cancer treatment applications, high-power ultrasound is focused at a target tissue volume to ablate the malignant tumour. The success of the procedure depends on the ability to accurately focus ultrasound and destroy the target tissue volume through coagulative necrosis whilst preserving the surrounding healthy tissue. Patient-specific treatment planning strategies are therefore being developed to increase the efficacy of such therapies, while reducing any damage to healthy tissue. These strategies require to use high-performance computing methods to solve ultrasound wave propagation in the body quickly and accurately. For realistic clinical scenarios, all numerical methods which employ volumetric meshes require several hours or days to solve the full-wave propagation on a computer cluster. The boundary element method (BEM) is an efficient approach for modelling the wave field because only the boundaries of the hard and soft tissue regions require discretisation. This paper presents a multiple-domain BEM formulation with a novel preconditioner for solving the Helmholtz transmission problem (HTP). This new formulation is efficient at high-frequencies and where high-contrast materials are present. Numerical experiments are performed to solve the HTP in multiple domains comprising: (i) human ribs, an idealised abdominal fat layer and liver tissue, (ii) a human kidney with a perinephric fat layer, exposed to the acoustic field generated by a high-intensity focused ultrasound (HIFU) array transducer. The time required to solve the equations associated with these problems on a single workstation is of the order of minutes. These results demonstrate the great potential of this new BEM formulation for accurately and quickly solving ultrasound wave propagation problems in large anatomical domains which is essential for developing treatment planning strategies.
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Affiliation(s)
- S R Haqshenas
- Department of Mechanical Engineering, University College London, London WC1E 7JE, UK; Department of Mathematics, University College London, London WC1H 0AY, UK.
| | - P Gélat
- Department of Mechanical Engineering, University College London, London WC1E 7JE, UK
| | - E van 't Wout
- Institute for Mathematical and Computational Engineering, School of Engineering and Faculty of Mathematics, Pontificia Universidad Católica de Chile, Santiago, Chile
| | - T Betcke
- Department of Mathematics, University College London, London WC1H 0AY, UK
| | - N Saffari
- Department of Mechanical Engineering, University College London, London WC1E 7JE, UK
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Wu N, Shen G, Qu X, Wu H, Qiao S, Wang E, Chen Y, Wang H. An efficient and accurate parallel hybrid acoustic signal correction method for transcranial ultrasound. Phys Med Biol 2020; 65:215019. [PMID: 32721943 DOI: 10.1088/1361-6560/abaa25] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Phased-control focused ultrasound transducers provide a new and noninvasive treatment method for brain disease. However, improving the accuracy of phase correction and reducing the calculation time during treatment have always been contradictory constraints. In this paper, a hybrid acoustic signal correction (HASC) method combined with k-Wave stage and holography stage was introduced for phase correction and simulation of transcranial focused ultrasound. The k-Wave stage is mainly used to calculate the sound field in a heterogeneous medium (skull), which divides the sound field calculation process into paths that can be calculated in parallel, and the transcranial correction phase can also be obtained during the calculation. The holography stage is sufficient to simulate the acoustic field in the homogenous intracranial medium after ultrasound transmitting through the skull. The agreement of the k-space corrected pseudospectral time domain method and HASC method was assessed by statistical methods: linear regression between the two methods provided a slope of 0.9735, intercept of 0.0078, and R 2 of 0.9982. The Bland-Altman method provided a bias of 0.0015 and 95% limits of agreement 0.065 apart. We demonstrated that the difference in sound intensity at the focal point corrected by HASC and time reversal phase correction method was 0.2% and 0.5% in the results of simulation and experiment, respectively. Not only that, the phase calculation time by the HASC phase correction method can be reduced to 11 min on a multi GPU array, which has clinical potential for ultrasound treatment of brain therapy.
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Affiliation(s)
- Nan Wu
- School of Biomedical Engineering, Shanghai Jiao Tong University, Shanghai 200030 People's Republic of China
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Cao R, Huang Z, Nabi G, Melzer A. Patient-Specific 3-Dimensional Model for High-Intensity Focused Ultrasound Treatment Through the Rib Cage: A Preliminary Study. JOURNAL OF ULTRASOUND IN MEDICINE : OFFICIAL JOURNAL OF THE AMERICAN INSTITUTE OF ULTRASOUND IN MEDICINE 2020; 39:883-899. [PMID: 31721248 DOI: 10.1002/jum.15170] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/13/2019] [Revised: 09/12/2019] [Accepted: 10/16/2019] [Indexed: 06/10/2023]
Abstract
OBJECTIVES The purpose of this study was to develop a patient-specific 3-dimensional model for high-intensity focused ultrasound (HIFU) treatment through the rib cage using patient data. METHODS Experimental testing to derive parameters used in defining the amount of energy and alteration needed in treatment protocols for upper abdominal disorders under the rib cage was performed. Reconstructed rib cage models based on patient data, tissue-mimicking material phantoms, and magnetic resonance imaging-guided HIFU using a multielement phased array transducer were used in the experiments. Changes in the focal temperature, acoustic power, and acoustic pressure distribution were investigated with and without the presence of the rib cage model. An ExAblate system (InSightec Ltd, Tirat Carmel, Israel) was used to sonicate phantoms by varying the target phantom or rib cage model location. RESULTS The effect of the rib cage on the acoustic pressure distribution and acoustic power was closely related to the anatomic structures of the ribs. Thermometry revealed that heating at the focus could be controlled by changing either the power or duration of HIFU application to improve the focal temperature change. The focal temperature change was found to be related to the distance between the rib cage model and focus and the shadow area on the transducer elements covered by the rib cage model in the beam path. CONCLUSIONS Experimental results suggest that the rib cage model is a valuable and useful tool that can provide realistic human anatomic structures and properties for evaluating the effects of the rib cage on ultrasound propagation.
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Affiliation(s)
- Rui Cao
- Tianjin Key Laboratory of Integrated Design and On-line Monitoring for Light Industry & Food Machinery and Equipment, College of Mechanical Engineering, Tianjin University of Science and Technology, Tianjin, China
| | - Zhihong Huang
- School of Science and Engineering, University of Dundee, Dundee, UK
| | - Ghulam Nabi
- School of Medicine, Ninewells Hospital, Dundee, UK
| | - Andreas Melzer
- Institute for Medical Science and Technology, Dundee, UK
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Qiao S, Elbes D, Boubriak O, Urban JPG, Coussios CC, Cleveland RO. Delivering Focused Ultrasound to Intervertebral Discs Using Time-Reversal. ULTRASOUND IN MEDICINE & BIOLOGY 2019; 45:2405-2416. [PMID: 31155405 DOI: 10.1016/j.ultrasmedbio.2019.04.023] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/16/2018] [Revised: 04/18/2019] [Accepted: 04/25/2019] [Indexed: 06/09/2023]
Abstract
Chronic low back pain causes more disability worldwide than any other condition and is thought to arise in part through loss of biomechanical function of degenerate intervertebral discs (IVDs). Current treatments can involve replacing part or all of the degenerate IVDs by invasive surgery. Our vision is to develop a minimally invasive approach in which high intensity focused ultrasound (HIFU) is used to mechanically fractionate degenerate tissue in an IVD; a fine needle is then used to first remove the fractionated tissue and then inject a biomaterial able to restore normal physiologic function. The goal of this manuscript is to demonstrate the feasibility of trans-spinal HIFU delivery using simulations of 3-D ultrasound propagation in models derived from patient computed tomography (CT) scans. The CT data were segmented into bone, fat and other soft tissue for three patients. Ultrasound arrays were placed around the waist of each patient model, and time-reversal was used to determine the source signals necessary to create a focus in the center of the disc. The simulations showed that for 0.5 MHz ultrasound, a focus could be created in most of the lumbar IVDs, with the pressure focal gain ranging from 3.2-13.7. In conclusion, it is shown that with patient-specific planning, focusing ultrasound into an IVD is possible in the majority of patients despite the complex acoustic path introduced by the bony structures of the spine.
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Affiliation(s)
- S Qiao
- Institute of Biomedical Engineering, Department of Engineering Science, University of Oxford, UK
| | - D Elbes
- Institute of Biomedical Engineering, Department of Engineering Science, University of Oxford, UK
| | - O Boubriak
- Institute of Biomedical Engineering, Department of Engineering Science, University of Oxford, UK
| | - J P G Urban
- Department of Physiology, Anatomy & Genetics, University of Oxford, UK
| | - C-C Coussios
- Institute of Biomedical Engineering, Department of Engineering Science, University of Oxford, UK
| | - R O Cleveland
- Institute of Biomedical Engineering, Department of Engineering Science, University of Oxford, UK.
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van 't Wout E, Gélat P, Betcke T, Arridge S. A fast boundary element method for the scattering analysis of high-intensity focused ultrasound. THE JOURNAL OF THE ACOUSTICAL SOCIETY OF AMERICA 2015; 138:2726-37. [PMID: 26627749 DOI: 10.1121/1.4932166] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
High-intensity focused ultrasound (HIFU) techniques are promising modalities for the non-invasive treatment of cancer. For HIFU therapies of, e.g., liver cancer, one of the main challenges is the accurate focusing of the acoustic field inside a ribcage. Computational methods can play an important role in the patient-specific planning of these transcostal HIFU treatments. This requires the accurate modeling of acoustic scattering at ribcages. The use of a boundary element method (BEM) is an effective approach for this purpose because only the boundaries of the ribs have to be discretized instead of the standard approach to model the entire volume around the ribcage. This paper combines fast algorithms that improve the efficiency of BEM specifically for the high-frequency range necessary for transcostal HIFU applications. That is, a Galerkin discretized Burton-Miller formulation is used in combination with preconditioning and matrix compression techniques. In particular, quick convergence is achieved with the operator preconditioner that has been designed with on-surface radiation conditions for the high-frequency approximation of the Neumann-to-Dirichlet map. Realistic computations of acoustic scattering at 1 MHz on a human ribcage model demonstrate the effectiveness of this dedicated BEM algorithm for HIFU scattering analysis.
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Affiliation(s)
- Elwin van 't Wout
- Department of Computer Science, University College London, London, United Kingdom
| | - Pierre Gélat
- Department of Mechanical Engineering, University College London, London, United Kingdom
| | - Timo Betcke
- Department of Mathematics, University College London, London, United Kingdom
| | - Simon Arridge
- Department of Computer Science, University College London, London, United Kingdom
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Gu J, Jing Y. Modeling of wave propagation for medical ultrasound: a review. IEEE TRANSACTIONS ON ULTRASONICS, FERROELECTRICS, AND FREQUENCY CONTROL 2015; 62:1979-1993. [PMID: 26559627 DOI: 10.1109/tuffc.2015.007034] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
Numerical modeling of medical ultrasound has advanced tremendously in the past two decades. This opens up a great number of opportunities for medical ultrasound and associated technologies. Numerous new governing equations and algorithms have emerged and been applied to studying various medical ultrasound applications, including ultrasound imaging, photo-acoustic imaging, and therapeutic ultrasound. In addition, thanks to the rapid development of computers, modeling acoustic wave propagation in three-dimensional, large-scale domains has become a reality. This article will provide an indepth literature and technical review of recent progress on numerical modeling of medical ultrasound. Future challenges will also be discussed.
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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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Gélat P, Ter Haar G, Saffari N. A comparison of methods for focusing the field of a HIFU array transducer through human ribs. Phys Med Biol 2014; 59:3139-71. [PMID: 24861888 DOI: 10.1088/0031-9155/59/12/3139] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
A forward model, which predicts the scattering by human ribs of a multi-element high-intensity focused ultrasound transducer, was used to investigate the efficacy of a range of focusing approaches described in the literature. This forward model is based on the boundary element method and was described by Gélat et al (2011 Phys. Med. Biol. 56 5553-81; 2012 Phys. Med. Biol. 57 8471-97). The model has since been improved and features a complex surface impedance condition at the surface of the ribs. The inverse problem of focusing through the ribs was implemented on six transducer array-rib topologies and five methods of focusing were investigated, including spherical focusing, binarized apodization based on geometric ray tracing, phase conjugation and the decomposition of the time-reversal operator method. The excitation frequency was 1 MHz and the array was of spherical-section type. Both human and idealized rib topologies were considered. The merit of each method of focusing was examined. It was concluded that the constrained optimization approach offers greater potential than the other focusing methods in terms of maximizing the ratio of acoustic pressure magnitudes at the focus to those on the surface of the ribs whilst taking full advantage of the dynamic range of the phased array.
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Affiliation(s)
- P Gélat
- National Physical Laboratory, Hampton Road, Teddington TW11 0LW, UK. Department of Mechanical Engineering, University College London, Torrington Place, London WC1E 7JE, UK
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