2009 IEEE International Ultrasonics Symposium最新文献

{"title":"Sonoporation of endothelial cells with CD31-targeted microbubbles at low acoustic pressures","authors":"K. Kooiman, Miranda Foppen-Harteveld, N. de Jong","doi":"10.1109/ULTSYM.2009.5442025","DOIUrl":"https://doi.org/10.1109/ULTSYM.2009.5442025","url":null,"abstract":"Until now, targeted microbubbles have only been used for molecular imaging, not drug delivery. Drug uptake using microbubbles can be induced by sonoporation, a method that induces transient cell membrane pores by oscillating or jetting microbubbles so that therapeutics can enter the cell. So far, sonoporation has only been induced using non-targeted microbubbles. This study focuses on inducing sonoporation with CD31-targeted microbubbles in endothelial cells. Targeted microbubble-cell behavior upon insonification at 1 MHz (6× 10 cycle sine-wave bursts, 80 kPa peak negative acoustic pressure) was studied with a high-speed camera. The cell-impermeable propidium iodide (PI) was used as indicator for increased endothelial cell membrane permeability due to sonoporation. During insonification, the adhered microbubbles oscillated and were not destroyed. Cell deformation was not detected. Microbubbles larger than 3.0 µm or a relative vibration ≫ 0.5 induced PI uptake in the area surrounding the bubble. This study reveals that targeted microbubbles can induce sonoporation. This feature may now be used in molecular imaging using ultrasound, thereby combining imaging and drug delivery.","PeriodicalId":368182,"journal":{"name":"2009 IEEE International Ultrasonics Symposium","volume":"56 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2009-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131447329","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"High temperature guided acoustic wave transducers using mechanical gratings","authors":"K.-T. Wu, W. Liu, Makiko Kobayashi, C. Jen, Y. Ono, M. Takeuchi","doi":"10.1109/ULTSYM.2009.5441430","DOIUrl":"https://doi.org/10.1109/ULTSYM.2009.5441430","url":null,"abstract":"Integrated and flexible guided acoustic wave transducers have been made using line shape mechanical gratings together with sol-gel fabricated integrated ultrasonic transducers at the opposite side. They can be used to generate and receive guided surface and plate acoustic waves and to operate up to 150°C. Preliminary results show the potentials of them for nondestructive evaluation and structural health monitoring applications.","PeriodicalId":368182,"journal":{"name":"2009 IEEE International Ultrasonics Symposium","volume":"27 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2009-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123495235","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Acoustic size distribution analyzer for microbubbles","authors":"D. Maresca, Marie Muller, M. Emmer, H. Vos, N. de Jong, A. V. D. van der Steen","doi":"10.1109/ULTSYM.2009.5441880","DOIUrl":"https://doi.org/10.1109/ULTSYM.2009.5441880","url":null,"abstract":"In this study, an acoustic size distribution measurement of the ultrasound contrast agent Definity™ was performed. Single lipid shelled microbubbles were insonified at 25 MHz, high above their resonance frequencies, so that their acoustic responses depend on their physical cross sections only. We calculated the size of each microbubble from the measured absolute backscattered pressures. The acoustic size measurements were compared to optical reference size measurements to test their accuracy. Our acoustic sizing method was applied to 88 individual Definity™ bubbles to derive a size distribution of this agent. The result showed agreement with the optical measurements of the same contrast agent population. The averaged sizes obtained acoustically differed by 26% with the optical measurement. This novel acoustic sizing method shows potential for estimating the size distribution of an ultrasound contrast agent noninvasively.","PeriodicalId":368182,"journal":{"name":"2009 IEEE International Ultrasonics Symposium","volume":"76 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2009-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128235870","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Comparison of pulse subtraction Doppler and pulse inversion Doppler","authors":"V. Mahue, Jean Martial Mari, Mx Tang, R. Eckersley","doi":"10.1109/ULTSYM.2009.5441909","DOIUrl":"https://doi.org/10.1109/ULTSYM.2009.5441909","url":null,"abstract":"A challenge in molecular imaging with targeted contrast agents is the development of methods able to detect and distinguish microbubbles attached to regions of disease from the high background signal from freely circulating microbubbles and tissue. Combining a nonlinear contrast agent detection technique with Doppler has potential to perform this discrimination. So far, pulse inversion Doppler (PID), is able to distinguish linear from nonlinear moving scatterers by making use of the even harmonics generated by the microbubbles. However it has been shown that adherent microbubbles emit a stronger fundamental signal than freely flowing ones. In this paper, a new Doppler technique based on pulse subtraction imaging (PSD) is described and compared with PID. The results show that PSD is able to differentiate bubble motion from tissue motion and could find applications in targeted microbubble imaging. For Doppler processing conducted at the fundamental frequency, the contrast to tissue ratio (CTR) in PSD was on average 3.3 (± 0.4) times higher than PID at a mechanical index (MI) of 0.1. At the harmonic frequency, PID has shown to have a 3.1 (± 0.4) times higher CTR than PSD. The CTR has also been shown to increase with increasing MI.","PeriodicalId":368182,"journal":{"name":"2009 IEEE International Ultrasonics Symposium","volume":"180 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2009-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114748235","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Flexible ultrasonic transducers for structural health monitoring of pipes at high temperatures","authors":"J. Shih, Makiko Kobayashi, C. Jen","doi":"10.1109/ULTSYM.2009.5441414","DOIUrl":"https://doi.org/10.1109/ULTSYM.2009.5441414","url":null,"abstract":"Piezoelectric films have been deposited by a sol-gel spray technique onto 75 µm thick metal membranes and have been fabricated into flexible ultrasonic transducers (FUTs). Such FUTs were glued and brazed onto steel pipes providing as on-site installation techniques for continuous thickness monitoring purposes at up to 490°C. At 150°C, the thickness measurement accuracy of a pipe with an outer diameter of 26.6 mm and a wall thickness of 2.5 mm was estimated to be 26 µm. Ultrasonic 4 by 16 element arrays were also fabricated and single element performance was measured.","PeriodicalId":368182,"journal":{"name":"2009 IEEE International Ultrasonics Symposium","volume":"5 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2009-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"121766192","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Using passive cavitation detection to observe postexcitation response of ultrasound contrast agents","authors":"D. King, M. Santin, M. J. Malloy, A. Roberts, A. Haak, J. Foiret, S. Haupert, S. Jafari, L. Bridal, W. O’Brien","doi":"10.1109/ULTSYM.2009.5441685","DOIUrl":"https://doi.org/10.1109/ULTSYM.2009.5441685","url":null,"abstract":"Passive cavitation detection was used to improve the experimental characterization of single ultrasound contrast agent microbubble responses to short, large amplitude pulses. Two situations were examined: isolated microbubbles in an unconstrained environment, and isolated microbubbles flowing through a tube. The microbubbles were categorized according to a classification scheme based on the presence or absence of postexcitation signals, which are secondary broadband spikes that may follow the principle oscillation of the ultrasound contrast agent in response to an insonifying pulse. Experiments were conducted for different frequencies, peak rarefactional pressures, flow rates, and types of microbubble. Postexcitation activity was found to increase as frequency decreased, acoustic pressure increased, and flow rate increased. Additionally, lipid-shelled microbubbles were found to exhibit greater postexcitation at lower acoustic pressure thresholds than albumin-shelled microbubbles.","PeriodicalId":368182,"journal":{"name":"2009 IEEE International Ultrasonics Symposium","volume":"35 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2009-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"121220782","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Development of transducer system for tissue harmonic imaging of long coded signal","authors":"M. Tanabe, K. Okubo, N. Tagawa","doi":"10.1109/ULTSYM.2009.5442052","DOIUrl":"https://doi.org/10.1109/ULTSYM.2009.5442052","url":null,"abstract":"Higher spatial resolution and higher signal-to-noise ratio (SNR) are important issues for the quality of the medical ultrasound image. The objective of this study is to develop a transducer system which can obtain the echo signals with high spatial resolution and high SNR using a pulse compression technique and tissue harmonic imaging. In previous study, we proposed inline transmitter/receiver system which has the potential to solve the problem. The system mainly consists of a PZN-PT, two PVDF films and polyethylene. If the PZN-PT transmits long coded signals in the system, both PVDF films directly receive the transmitted signals, while just one of them receives the echo signals from targets. Although the signal obtained by the PVDF film placed on the transmission side of the PZN-PT contains the second harmonic components generated by tissue propagation, the echo signals and the transmitted signal directly received from the PZN-PT are mixed. To separate those signals, by connecting electric wires of two PVDF films, two signals obtained by two PVDF films are subtracted and the only differential signal; i.e. the echo signals from the targets, are obtained. Although the inline transmitter/receiver system has been able to certify the usefulness, the system also has a problem that one of two transmitted signals is undesirable and should be decreased. For the solution of the problem, two types are proposed in this study; Type-1 reflects and absorbs undesirable transmitted signals, and Type-2 reflects desirable transmitted signals and echo signals from targets. The both systems mainly consist of a PZN-PT, two PVDF films, polyethylene and a reflector. In this study, we investigate the influence of the reflector with various distance between the transducer and the reflector using PZFlex which is a standard finite element method (FEM) simulator for ultrasound propagation. As a result, it is shown that there is an optimal distance, and we can extract the harmonic components from the echo signals if the PZN-PT receives the echo signals before finishing transmitting. Subsequently, the echo signals obtained by two proposed systems are described and finally the feasibility of the proposed system is shown.","PeriodicalId":368182,"journal":{"name":"2009 IEEE International Ultrasonics Symposium","volume":"112 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2009-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128001565","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Tapered transmission line technique based graded matching layers for thickness mode piezoelectric transducers","authors":"S. Ramadas, R. O’Leary, A. Mulholland, G. Hayward, A. Mackintosh, A. Trogé, R. Pethrick","doi":"10.1109/ULTSYM.2009.5441463","DOIUrl":"https://doi.org/10.1109/ULTSYM.2009.5441463","url":null,"abstract":"Conventionally, in order to acoustically match thickness mode piezoelectric transducers to a low acoustic impedance load medium, multiple quarter wavelength (QW) matching layers are employed at the front face of the device. Typically a number of layers, 2–4 in number, are employed resulting in discrete impedance steps within the acoustic matching scheme. This can result in impedance matching with limited bandwidth characteristics. This paper investigates the application of tapered transmission line filter theory to implement a graded impedance profile, through the thickness of the matching layer scheme, to solve the impedance mismatch problem whilst accounting for enhanced transducer sensitivity and bandwidth.","PeriodicalId":368182,"journal":{"name":"2009 IEEE International Ultrasonics Symposium","volume":"24 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2009-09-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128031075","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Time-domain model of the ultrasonic wave propagation in an inhomogeneous anisotropic viscoelastic fluid/solid multilayer medium: application to cortical bone","authors":"G. Haiat, S. Naili, Mai-Ba Vu, Q. Grimal, M. Talmant, C. Desceliers, Christian Soize","doi":"10.1109/ULTSYM.2009.5441746","DOIUrl":"https://doi.org/10.1109/ULTSYM.2009.5441746","url":null,"abstract":"Cortical bone quality is assessed in clinical practice using axial transmission (AT) devices, which allow the measurement of quantitative ultrasonic parameters such as the first arriving signal (FAS) velocity. However, the physical interaction between an ultrasonic wave and cortical bone remains poorly understood due to the complex nature of the bone structure. Cortical bone and the surrounding soft tissues are attenuating media, which might affect the analysis of the results obtained with AT devices. Moreover, cortical bone is highly heterogeneous and a gradient of material properties from the outer to inner part of the cortical shell has been reported. The aim of this work is to evaluate the effect of anisotropic heterogeneous dissipative phenomena occurring in bone and in soft tissues on the ultrasonic response of the bone structure. A two-dimensional finite element time-domain method is derived to model transient wave propagation in a three-layer medium composed of an inhomogeneous transverse isotropic viscoelastic solid layer sandwiched between two dissipative acoustic fluid layers. The model couples acoustic propagation in both dissipative acoustic fluid media with the response of the solid whose constitutive equation is based on the linear theory of viscoelasticity without memory. Bone viscoelasticity is assumed to be heterogeneous and a constant spatial gradient of viscoelastic properties is considered for a value of bone thickness corresponding to a relatively thick bone. Realistic variations of the viscosity of the soft tissues within the physiological range do not affect the FAS velocity in any configuration. However, when the viscoelastic bone parameters vary within their physiological range, changes of the value of the FAS velocity (up to 301 m/s) are comparable to what has been obtained for variation of the elastic parameters. The components of the viscoelastic tensor affecting the results are the same as those of the stiffness tensor found. Our results highlight the importance of accounting for absorption phenomena occurring in cortical bone for the analysis of ultrasonic measurements with AT device.","PeriodicalId":368182,"journal":{"name":"2009 IEEE International Ultrasonics Symposium","volume":"17 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2009-09-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125246688","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Measurements under high pressure of ultrasonic wave velocity in glycerol","authors":"H. Khelladi, F. Plantier, J. Daridon, H. Djelouah","doi":"10.1109/ULTSYM.2009.5441708","DOIUrl":"https://doi.org/10.1109/ULTSYM.2009.5441708","url":null,"abstract":"Glycerol has been the subject of significant scientist interest. Indeed, glycerol is a polyalcohol and the presence of three hydroxyl groups per molecule makes glycerol a complex system to explore. The purpose of this investigation is to measure under high pressure the ultrasonic wave velocity in glycerol, from which a number of important thermodynamic properties could be derived and determined as a function of pressure and temperature. Pressure and temperature ranges exploited in this experimental investigation of various glycerol properties, are extended from 0.1 MPa to 100 MPa and from 10°C to 100°C, respectively. A high pressure measurement cell equipped with temperature and pressure monitoring and control instrumentation is used. A time of flight method is exploited to measure, under high pressure, the ultrasonic wave velocity at different temperatures. The resulting experimental data of ultrasonic wave velocity in glycerol combined with measurements at atmospheric pressure, of density, specific heat and the thermal expansion coefficient are used to derive density at elevated pressures. As isentropic compressibility is linked to ultrasonic wave velocity and density by means of the Newton-Laplace equation, this intrinsic physical property is easily deduced. These results led to the behavior of each property as a function of temperature and pressure.","PeriodicalId":368182,"journal":{"name":"2009 IEEE International Ultrasonics Symposium","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2009-09-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129790390","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}