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Vu T, Klippel P, Canning AJ, Ma C, Zhang H, Kasatkina LA, Tang Y, Xia J, Verkhusha VV, Vo-Dinh T, Jing Y, Yao J. On the Importance of Low-Frequency Signals in Functional and Molecular Photoacoustic Computed Tomography. IEEE TRANSACTIONS ON MEDICAL IMAGING 2024; 43:771-783. [PMID: 37773898 PMCID: PMC10932611 DOI: 10.1109/tmi.2023.3320668] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/01/2023]
Abstract
In photoacoustic computed tomography (PACT) with short-pulsed laser excitation, wideband acoustic signals are generated in biological tissues with frequencies related to the effective shapes and sizes of the optically absorbing targets. Low-frequency photoacoustic signal components correspond to slowly varying spatial features and are often omitted during imaging due to the limited detection bandwidth of the ultrasound transducer, or during image reconstruction as undesired background that degrades image contrast. Here we demonstrate that low-frequency photoacoustic signals, in fact, contain functional and molecular information, and can be used to enhance structural visibility, improve quantitative accuracy, and reduce spare-sampling artifacts. We provide an in-depth theoretical analysis of low-frequency signals in PACT, and experimentally evaluate their impact on several representative PACT applications, such as mapping temperature in photothermal treatment, measuring blood oxygenation in a hypoxia challenge, and detecting photoswitchable molecular probes in deep organs. Our results strongly suggest that low-frequency signals are important for functional and molecular PACT.
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Huang L, Qiao S, Ling W, Wang W, Feng Q, Cao J, Luo Y. Technical note: High-efficient and wireless transcranial ultrasound excitation based on electromagnetic acoustic transducer. Med Phys 2024; 51:662-669. [PMID: 37815210 DOI: 10.1002/mp.16732] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2023] [Revised: 08/25/2023] [Accepted: 08/28/2023] [Indexed: 10/11/2023] Open
Abstract
BACKGROUND The generation of transcranial ultrasound is usually based on the piezoelectric effect, so it is necessary to attach transducers around the skull. However, the skull will cause serious attenuation and scattering of ultrasound, which makes it particularly difficult for transcranial ultrasound imaging and modulation. PURPOSE In transcranial ultrasound imaging, there is significant attenuation and scattering of ultrasound waves by the skull bone. To mitigate this influence and enable precise imaging and high-efficient transcranial ultrasound for specific patients (such as stroke patients who already require craniotomy as part of their surgical care), this paper proposes to use EMAT to excite metal plates placed inside the skull based on the excellent penetration characteristics of EM waves into the skull, generating ultrasound signals, which can completely avoid the influence of skull on ultrasound transmission. METHODS Based on an efficient wireless transcranial ultrasound experimental platform, we first verified that the skull would not affect the propagation of electromagnetic waves generated by EMAT. In addition, the distribution of the transcranial sound field generated by EMAT was measured. RESULTS EMAT can generate 1.0 MHz ultrasound by wireless excitation of a 0.1 mm thick copper plate through an adult skull with a thickness of ∼1 cm, and the frequency and amplitude of the generated ultrasound are not affected by the skull. The results indicated that the electromagnetic waves successfully penetrated the skull, with a recorded strength of approximately 2 mV. We also found that the ultrasound signals generated by the EMAT probe through the skull remained unaffected, measuring around 2 mV. In addition, the measurement of the transcranial sound field distribution (80*50 mm2 ) generated by EMAT shows that compared with the traditional extracranial ultrasound generation method, the sound field distribution generated by the wireless excitation of the intracranial copper plate based on EAMT is no longer affected by the uneven and irregular skull. CONCLUSION Our experiments involved validating the penetration capabilities of electromagnetic waves utilizing the EMAT probe through a 7 (5+2) mm thick organic glass plate and a real human skull ranging from 8 to 15 mm in thickness. The efficient and wireless transcranial ultrasound excitation proposed in this paper may be possible for transcranial ultrasound imaging and therapy.
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Affiliation(s)
- Lin Huang
- School of Electronic Science and Engineering, University of Electronic Science and Technology of China, Chengdu, China
- Yangtze Delta Region Institute (Huzhou), University of Electronic Science and Technology of China, Huzhou, China
- Zhangjiang Laboratory, Shanghai, China
| | - Shuaiqi Qiao
- School of Electronic Science and Engineering, University of Electronic Science and Technology of China, Chengdu, China
- Yangtze Delta Region Institute (Huzhou), University of Electronic Science and Technology of China, Huzhou, China
- Zhangjiang Laboratory, Shanghai, China
| | - Wenwu Ling
- West China Hospital, Sichuan University, Chengdu, China
| | - Weipeng Wang
- School of Electronic Science and Engineering, University of Electronic Science and Technology of China, Chengdu, China
- Yangtze Delta Region Institute (Huzhou), University of Electronic Science and Technology of China, Huzhou, China
- Zhangjiang Laboratory, Shanghai, China
| | - Qikaiyi Feng
- School of Electronic Science and Engineering, University of Electronic Science and Technology of China, Chengdu, China
- Yangtze Delta Region Institute (Huzhou), University of Electronic Science and Technology of China, Huzhou, China
- Zhangjiang Laboratory, Shanghai, China
| | - Jiazhi Cao
- West China Hospital, Sichuan University, Chengdu, China
| | - Yan Luo
- West China Hospital, Sichuan University, Chengdu, China
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Chen T, Chen J, Yi Z, Zheng C, Zhou L, Wu Y, Cai F, Qin J, Hong Z, Huang Y. Enhanced Ultrasound Transmission through Skull Using Flexible Matching Layer with Gradual Acoustic Impedance. ACS APPLIED MATERIALS & INTERFACES 2023; 15:55510-55517. [PMID: 37991837 DOI: 10.1021/acsami.3c13872] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/23/2023]
Abstract
Transcranial ultrasound imaging and therapy have gained significant attention due to their noninvasive nature, absence of ionizing radiation, and portability. However, the presence of the skull, which has a high acoustic impedance, presents a challenge for the penetration of ultrasound into intracranial tissue. This leads to a low transmission of ultrasound through the skull, hindering energy focusing and imaging quality. To address this challenge, we propose a novel approach that utilizes a flexible matching layer with gradual acoustic impedance to enhance ultrasound transmission through the skull. This matching layer is constructed using Poly(dimethylsiloxane) (PDMS)/tungsten powders as the structural component responsible for the gradual impedance, while agarose serves as the flexible matrix. Our simulation and experimental results demonstrate that the matching layer with an exponential gradual acoustic impedance significantly improves the ultrasound transmission coefficient across a wide frequency range compared to traditional quarter wavelength matching layers. Specifically, at 2 MHz, the maximum transmission coefficient reaches 49.5%, more than four times higher than that of the skull without a matching layer (only 11.7%). Additionally, the good flexibility of our matching layer ensures excellent adhesion to the curved surface of the skull, further enhancing its application potential in transcranial ultrasound imaging and therapy. The improved transmission performance allows for a lower ultrasound transmission power, effectively addressing overheating and safety issues.
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Affiliation(s)
- Tiantian Chen
- School of Materials Science and Engineering, State Key Laboratory of Silicon and Advanced Semiconductor Materials, Zhejiang University, Hangzhou, Zhejiang 310027, China
| | - Jie Chen
- School of Materials Science and Engineering, State Key Laboratory of Silicon and Advanced Semiconductor Materials, Zhejiang University, Hangzhou, Zhejiang 310027, China
| | - Zhenyu Yi
- School of Materials Science and Engineering, State Key Laboratory of Silicon and Advanced Semiconductor Materials, Zhejiang University, Hangzhou, Zhejiang 310027, China
| | - Congqin Zheng
- School of Materials Science and Engineering, State Key Laboratory of Silicon and Advanced Semiconductor Materials, Zhejiang University, Hangzhou, Zhejiang 310027, China
| | - Linming Zhou
- School of Materials Science and Engineering, State Key Laboratory of Silicon and Advanced Semiconductor Materials, Zhejiang University, Hangzhou, Zhejiang 310027, China
| | - Yongjun Wu
- School of Materials Science and Engineering, State Key Laboratory of Silicon and Advanced Semiconductor Materials, Zhejiang University, Hangzhou, Zhejiang 310027, China
| | - Feiyan Cai
- Paul C. Lauterbur Research Center for Biomedical Imaging, Shenzhen Institutes of Advanced Technology, Chinese Academy of Sciences, Shenzhen 518055, China
| | - Jiale Qin
- Department of Ultrasound, Women's Hospital, Zhejiang University School of Medicine, Hangzhou, Zhejiang 310006, China
| | - Zijian Hong
- School of Materials Science and Engineering, State Key Laboratory of Silicon and Advanced Semiconductor Materials, Zhejiang University, Hangzhou, Zhejiang 310027, China
| | - Yuhui Huang
- School of Materials Science and Engineering, State Key Laboratory of Silicon and Advanced Semiconductor Materials, Zhejiang University, Hangzhou, Zhejiang 310027, China
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Pydi YS, Nath A, Chawla A, Mukherjee S, Lalwani S, Malhotra R, Datla NV. Strain-rate-dependent material properties of human lung parenchymal tissue using inverse finite element approach. Biomech Model Mechanobiol 2023; 22:2083-2096. [PMID: 37535253 DOI: 10.1007/s10237-023-01751-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2023] [Accepted: 07/09/2023] [Indexed: 08/04/2023]
Abstract
Automobile crashes and blunt trauma often lead to life-threatening thoracic injuries, especially to the lung tissues. These injuries can be simulated using finite element-based human body models that need dynamic material properties of lung tissue. The strain-rate-dependent material parameters of human parenchymal tissues were determined in this study using uniaxial quasi-static (1 mm/s) and dynamic (1.6, 3, and 5 m/s) compression tests. A bilinear material model was used to capture the nonlinear behavior of the lung tissue, which was implemented using a user-defined material in LS-DYNA. Inverse mapping using genetic algorithm-based optimization of all experimental data with the corresponding FE models yielded a set of strain-rate-dependent material parameters. The bilinear material parameters are obtained for the strain rates of 0.1, 100, 300, and 500 s-1. The estimated elastic modulus increased from 43 to 153 kPa, while the toe strain reduced from 0.39 to 0.29 when the strain rate was increased from 0.1 to 500 s-1. The optimized bilinear material properties of parenchymal tissue exhibit a piecewise linear relationship with the strain rate.
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Affiliation(s)
- Yeswanth S Pydi
- Department of Mechanical Engineering, Indian Institute of Technology Delhi, New Delhi, 110016, India.
| | - Atri Nath
- Department of Mechanical Engineering, Indian Institute of Technology Delhi, New Delhi, 110016, India
| | - Anoop Chawla
- Department of Mechanical Engineering, Indian Institute of Technology Delhi, New Delhi, 110016, India
| | - Sudipto Mukherjee
- Department of Mechanical Engineering, Indian Institute of Technology Delhi, New Delhi, 110016, India
| | - Sanjeev Lalwani
- Department of Forensic Science and Toxicology, All India Institute of Medical Sciences, New Delhi, India
| | - Rajesh Malhotra
- Department of Orthopaedics, All India Institute of Medical Sciences, New Delhi, India
| | - Naresh V Datla
- Department of Mechanical Engineering, Indian Institute of Technology Delhi, New Delhi, 110016, India
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Chan MYM, Ling YT, Chen XY, Chan ST, Kwong KK, Zheng YP. Success Rate of Transcranial Doppler Scanning of Cerebral Arteries at Different Transtemporal Windows in Healthy Elderly Individuals. ULTRASOUND IN MEDICINE & BIOLOGY 2023; 49:588-598. [PMID: 36400675 DOI: 10.1016/j.ultrasmedbio.2022.10.013] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/08/2022] [Revised: 10/19/2022] [Accepted: 10/21/2022] [Indexed: 06/16/2023]
Abstract
This study measured the rates of success in applying transcranial Doppler (TCD) scanning at the middle, posterior and anterior temporal windows (MTW, PTW and ATW) in the elderly. A hand-held 1.6-MHz pulsed-wave TCD transducer was used to search for cerebral arteries at MTW, PTW and ATW locations. Physical attributes of the head, including head circumference and the distance between tragi on both sides ("tragus-to-tragus arc length"), were also measured to explore the associations with successful rates. Among 396 healthy elderly participants (aged 62.6 ± 6.0 y, 140 men), 81.1% (n = 321; 127 men) had one or more temporal windows penetrable by TCD ultrasound (n = 286 [72.2%] at MTW, n = 195 [49.2%] at PTW and n = 106 [26.8%] at ATW). Regression analysis revealed that successful scanning increased significantly in male participants at three window locations. Younger age significantly increased successful scanning at the MTW and ATW. Smaller tragus-to-tragus arc length increased successful scanning at the MTW, but unsuccessful scanning at the ATW. Our findings support using MTW as the first location when positioning the TCD transducer for the scanning of cerebral arteries in the elderly population. When performing TCD scanning on two temporal windows, we propose choosing the MTW and PTW.
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Affiliation(s)
- Mandy Yuen-Man Chan
- Department of Biomedical Engineering, Hong Kong Polytechnic University, Hong Kong, China
| | - Yan To Ling
- Department of Biomedical Engineering, Hong Kong Polytechnic University, Hong Kong, China
| | - Xiang-Yan Chen
- Department of Health Technology and Informatics, Hong Kong Polytechnic University, Hong Kong, China; Research Institute for Smart Ageing, Hong Kong Polytechnic University, Hong Kong, China
| | - Suk-Tak Chan
- Athinoula A. Martinos Center for Biomedical Imaging, Department of Radiology, Massachusetts General Hospital, Charlestown, Massachusetts, USA
| | - Kenneth K Kwong
- Athinoula A. Martinos Center for Biomedical Imaging, Department of Radiology, Massachusetts General Hospital, Charlestown, Massachusetts, USA
| | - Yong-Ping Zheng
- Department of Biomedical Engineering, Hong Kong Polytechnic University, Hong Kong, China; Research Institute for Smart Ageing, Hong Kong Polytechnic University, Hong Kong, China.
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Chen C, Huang Y, Chen P, Hsu Y, Jaw F, Ho M. Modification of gelatin and photocured
3D
‐printed resin to prepare biomimetic phantoms for ultrasound‐guided minimally invasive surgeries. POLYM ENG SCI 2023. [DOI: 10.1002/pen.26216] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Affiliation(s)
- Chien‐Hua Chen
- Department of Biomedical Engineering National Taiwan University Taipei City Taiwan
| | - Yi‐Fan Huang
- Department of Chemical Engineering National Taiwan University of Science and Technology Taipei City Taiwan
| | - Po‐Hao Chen
- Department of Chemical Engineering National Taiwan University of Science and Technology Taipei City Taiwan
| | - Yu‐Tung Hsu
- Department of Chemical Engineering National Taiwan University of Science and Technology Taipei City Taiwan
| | - Fu‐Shan Jaw
- Department of Biomedical Engineering National Taiwan University Taipei City Taiwan
| | - Ming‐Hua Ho
- Department of Chemical Engineering National Taiwan University of Science and Technology Taipei City Taiwan
- R&D Center for Membrane Technology National Taiwan University of Science and Technology Taipei Taiwan
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Guided Waves in the Skull. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2022; 1364:411-422. [DOI: 10.1007/978-3-030-91979-5_19] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
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