2009 IEEE International Ultrasonics Symposium最新文献

{"title":"Preserving speckle statistics in minimum-variance beamformed images: the effectiveness of spatial compounding","authors":"F. Vignon, M. Burcher","doi":"10.1109/ULTSYM.2009.5441569","DOIUrl":"https://doi.org/10.1109/ULTSYM.2009.5441569","url":null,"abstract":"Data-dependent apodization techniques such as the minimum-variance beamformer (MVB) can beat the diffraction limit of the conventional Delay-and-Sum (DAS) beamformer, yielding enhanced resolution and contrast. However, the MVB algorithm strongly increases the speckle variance. This needs to be compensated in order for the MVB algorithm to be clinically successful. This paper shows that combining the MVB with spatial compounding yields unprecedented image quality with significantly increased lateral resolution and decreased clutter compared to conventional DAS imaging, without the drawback of increased speckle variance.","PeriodicalId":368182,"journal":{"name":"2009 IEEE International Ultrasonics Symposium","volume":"15 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2009-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"117128164","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":"Performance of the Transverse Oscillation method using beamformed data from a commercial scanner","authors":"M. Pihl, S. Nikolov, Per Haugaard, M. Hemmsen, J. Jensen","doi":"10.1109/ULTSYM.2009.5441954","DOIUrl":"https://doi.org/10.1109/ULTSYM.2009.5441954","url":null,"abstract":"Blood velocity estimates using conventional color flow imaging (CFI) or Doppler techniques are angle dependent. One of the proposed techniques to overcome this limitation is the Transverse Oscillation (TO) method, which also estimates the lateral velocity components. The performance of this is evaluated on a commercial platform. Beamformed data are acquired using a commercial BK Medical scanner as opposed to the previously reported results obtained with the experimental scanner RASMUS. The implementation is evaluated using an in-house circulating flow rig by calculating the relative mean standard deviation and bias of the velocity components. The relative mean standard deviation decreases as the number of shots per estimate increases and a value of 5% is obtained for 64 shots per estimate. For a center frequency of 5 MHz at 60°, 75°, and 90°, the relative mean bias varies from 21% to 27% and is lowest at a transmit focal depth close to the center of the vessel. The present performance is comparable with the results from the experimental scanner and simulations. It is obtained with only few changes to the conventional CFI setup and further optimization can improve the performance. This illustrates the feasibility of implementing the TO method on a commercial platform for real-time estimation.","PeriodicalId":368182,"journal":{"name":"2009 IEEE International Ultrasonics Symposium","volume":"18 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2009-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"121113228","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":"Anti-tumor effects of cavitation induced with phase-change nano droplet and ultrasound","authors":"K. Kawabata, R. Asami, T. Azuma, H. Yoshikawa, S. Umemura","doi":"10.1109/ULTSYM.2009.5441532","DOIUrl":"https://doi.org/10.1109/ULTSYM.2009.5441532","url":null,"abstract":"We performed a study to look into the therapeutic application of a novel diagnostic and therapeutic agent, phase change nano droplet (PCND), in combination with 1-MHz ultrasound. It was found using gel phantoms that PCND works as a cavitation accelerator for a 1-MHz ultrasound only when an ultrasound which changes the phase of PCND from liquid to gas (phase change ultrasound) is exposed in advance. A nano droplet that cannot change its phase to a gas does not work even in the presence of the phase change ultrasound. The cavitation induction with the aid of a PCND was observable by B-mode echography as a brightness change. Such a brightness change was also observed in in vivo experiments on tumor baring mice in the presence of a PCND and a phase change ultrasound. Moreover, tissue damage was observed at the site of the brightness change. The lack of either a PCND or a phase change ultrasound did not induce any brightness change, suggesting the same mechanism as a gel phantom works in living tissues. Our results are promising for use in a noble ultrasound therapy system with high selectivity and safety while improving the throughput of current ultrasound tumor treatment systems.","PeriodicalId":368182,"journal":{"name":"2009 IEEE International Ultrasonics Symposium","volume":"18 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2009-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"124944106","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":"Energy-based adaptive focusing: Optimal ultrasonic focusing using magnetic resonance guidance","authors":"B. Larrat, M. Pernot, G. Montaldo, M. Fink, M. Tanter","doi":"10.1063/1.3367125","DOIUrl":"https://doi.org/10.1063/1.3367125","url":null,"abstract":"Adaptive focusing of ultrasonic waves is performed under the guidance of a Magnetic Resonance (MR) system. The technique is based on the maximization of the ultrasonic wave intensity at a target point. The wave intensity is indirectly estimated from the local tissue motion induced at the chosen focus by the acoustic radiation force of the ultrasonic beam. A motion sensitive MR sequence is used to measure the resulting local tissue displacements. Based on the transmission of a set of spatially coded ultrasonic waves, a non iterative inversion process is used to estimate the phase aberrations induced by the propagation medium and to maximize the acoustical intensity at the target. Both programmable and physical aberrating layers introducing strong distortions (up to 2π radians) are recovered within acceptable errors (≪0.8 rad). This non invasive technique is shown to accurately correct the phase aberrations in a phantom gel with negligible heat deposition and limited acquisition time. These refocusing performances demonstrate a major potential in the field of MR-Guided Ultrasound Therapy in particular for transcranial brain HIFU.","PeriodicalId":368182,"journal":{"name":"2009 IEEE International Ultrasonics Symposium","volume":"34 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2009-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"124982897","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-resolution ultrasonic monitoring of cellular differentiation in an ex vivo produced oral mucosal equivalent (EVPOME)","authors":"F. Winterroth, S. Hollister, K. Hollman, J. Fowlkes, S. Feinberg, S. Kuo, K. Izumi","doi":"10.1109/ULTSYM.2009.5441773","DOIUrl":"https://doi.org/10.1109/ULTSYM.2009.5441773","url":null,"abstract":"Background, Motivation and Objective This study examines the use of high-resolution ultrasound to monitor an ex vivo produced oral mucosal equivalent (EVPOME) as it develops from oral keratinocytes being seeded on a dermal cadaveric scaffold, with surface variations, into a stratified uniform cellular layer. Ultrasonic profilometry should be able to detect filling and smoothing of surface irregularities as seeded cells proliferate. As these tissue-engineered structures develop, seeded cells stratify due to their differentiation in which they produce a keratinized protective upper layer. These cells change in shape and composition, lose water content, and accumulate proteins (keratins) - transformations which could alter ultrasonic backscatter. If non-invasive ultrasonic monitoring could be developed then tissue cultivation could be adjusted in-process to account for variations in the development and manufacture of the stratified cellular layer.","PeriodicalId":368182,"journal":{"name":"2009 IEEE International Ultrasonics Symposium","volume":"30 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2009-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"126002673","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":"Enhancement of muscle fibers in ultrasound images using Gabor filters","authors":"Yongjin Zhou, Y. Zheng","doi":"10.1109/ULTSYM.2009.5441467","DOIUrl":"https://doi.org/10.1109/ULTSYM.2009.5441467","url":null,"abstract":"In this study, the Gabor filter bank technique was applied to the biceps and gastrocnemius ultrasound images to longitudinally enhance the coherently oriented and hyperechoic perimysiums regions. The method involved three steps, orientation field estimation, frequency map computation and Gabor filtering. The method was evaluated using a simulated image distorted with multiplicative speckle noises, where the “muscles” were arranged in a bipennate fashion with a central “aponeurosis”. After the enhancement using the proposed method, most of the original hyperechoic bands in the simulated image could be recovered and the noises in other locations were greatly reduced. The proposed method was also tested on biceps sonograms collected from 4 healthy adult subjects. Based on the filtering results, the hyperechoic regions, especially the fibroadipose septas, could be enhanced in several aspects, such as the completion of broken but coherently oriented regions. It is believed that the proposed method have potentials in assisting the visualization of strongly oriented patterns in ultrasound images and especially the quantitative estimation of muscle thickness, muscle fiber pennation angle and fascicle length.","PeriodicalId":368182,"journal":{"name":"2009 IEEE International Ultrasonics Symposium","volume":"27 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2009-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"126075707","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":"Real-time simulations and experiments on ultrahigh frequency surface waves in micro-structured phononic crystals","authors":"I. Veres, D. Profunser, O. Wright, O. Matsuda, U. Lang","doi":"10.1109/ULTSYM.2009.5441862","DOIUrl":"https://doi.org/10.1109/ULTSYM.2009.5441862","url":null,"abstract":"We investigate experimentally and by numerical simulation the interaction between ultrahigh frequency surface acoustic waves (SAW) and periodic microstructures. We use both one-dimensional (1D) phononic crystals consisting of copper lines embedded in silicon oxide and 2D phononic crystals consisting of air-filled holes etched as a square lattice in a silicon substrate. Experimental results obtained by ultrashort pulsed optical excitation and interferometric detection are compared to time-domain finite element (FEM) simulations of the propagating ultrahigh frequency SAW with frequency components up to ~1 GHz in these phononic crystals, allowing the investigation of SAW scattering and phononic band structure. Good agreement was obtained between simulation and experiment.","PeriodicalId":368182,"journal":{"name":"2009 IEEE International Ultrasonics Symposium","volume":"471 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2009-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123664016","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":"Speckle removal from heterogeneous-tissue signals using independent component analysis","authors":"Tadashi Yamaguchi, Tomoyuki Iwashina, N. Kamiyama, Jonathan Mamou, H. Hachiya","doi":"10.1109/ULTSYM.2009.5441728","DOIUrl":"https://doi.org/10.1109/ULTSYM.2009.5441728","url":null,"abstract":"In order to diagnose fibrosis quantitatively, a technique to extract fiber structure and suppress speckle from the echo data acquired using available clinical ultrasonic diagnostic instruments would be very valuable. To meet this need, we propose to apply independent component analysis (ICA) to separate the signals returning from clinical tissue fiber structures from the speckle signals. To use ICA and to remove speckle, data acquired from a normal tissue-mimicking phantom are acquired to characterize speckle and used to correct for speckle in clinical echo-signal data. Results showed satisfactory separation of speckle signals and fiber-tissue echo signals. However, results indicated that the ability of the ICA algorithm to correctly image fiber tissue structures depended greatly on whether the speckle in the clinical and tissue-mimicking images had same properties.","PeriodicalId":368182,"journal":{"name":"2009 IEEE International Ultrasonics Symposium","volume":"30 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2009-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125514905","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":"A novel technique for measuring ultrasound backscatter from single micron-sized objects","authors":"O. Falou, Min Rui, Ahmed El-Kaffas, J. Kumaradas, Michael C. Kolios","doi":"10.1109/ULTSYM.2009.5441887","DOIUrl":"https://doi.org/10.1109/ULTSYM.2009.5441887","url":null,"abstract":"The measurement of the ultrasound backscatter from individual micron-sized objects is required to gain an understanding of the behavior of both weak (cells) and strong (contrast agents) scatterers for applications ranging from tissue characterization to molecular imaging. However, obtaining such a response remains a challenge. For instance, the presence of air bubbles in a suspension of cells during measurements of cell backscatter may lead to the incorrect interpretation of the backscattered signals. In addition, the size and shape of the single object that produces an ultrasound backscatter signal are critical input parameters to theoretical models, yet hard to be measured experimentally. In this work, a novel technique combining a Xenoworks microinjection system (Sutter, Inc., Los Angeles, CA) with co-registered Olympus IX71 inverted microscope (Olympus America, Inc., Center Valley, PA) and a VEVO770 Ultrasound imaging device (VisualSonics, Inc., Toronto, ON) was developed in which the ultrasound backscatter response from a single object was obtained under optical microscope guidance. This technique provides accurate information about the size and shape of the object. Two transducers of central frequencies of 25 and 55 MHz were used (for a total spectrum of 12–57 MHz). The foci of the optical lens and the transducer were aligned to obtain optical and ultrasonic images of the same region. The object of interest was attached to the micropipette (using negative pressure) and then released from the micropipette (using positive pressure and/or tapping on the micropipette) while imaging it both optically and ultrasonically. In order to calibrate the system, a micropipette was used to grab a 20 µm polystyrene microsphere from a suspension of microspheres in degassed water by applying a pressure of −18.9 kPa. The microsphere was released by applying a pressure of +35.0 kPa. During the release, optical and ultrasonic raw RF lines were obtained. These lines were then used to obtain the power spectral plot of individual microspheres which were compared to analytical solutions. A very good agreement was found (error of 1%) between the measured backscatter response of microspheres and that of a Faran model of an elastic sphere. Extension of this method to prostate carcinoma (PC-3) cells showed a good agreement (error of 5%) when compared to the Anderson fluid sphere model. This technique is capable of providing accurate measurements of the backscatter from individual objects and is currently being used to deduce the backscatter response from other cell lines of different sizes and from ultrasound contrast agents either in isolation or when attached to a cell. The advantages of the technique along with its future applications are discussed.","PeriodicalId":368182,"journal":{"name":"2009 IEEE International Ultrasonics Symposium","volume":"38 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2009-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"126756911","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":"An annular array with fiber composite microstructure for far field NDT imaging applications","authors":"S. Ramadas, J. Dziewierz, R. O’Leary, A. Gachagan, A. Velichko, P. Wilcox","doi":"10.1109/ULTSYM.2009.5441460","DOIUrl":"https://doi.org/10.1109/ULTSYM.2009.5441460","url":null,"abstract":"This paper describes the design and fabrication of a reduced element count annular array for far field NDT imaging applications, built with a random fiber piezoelectric composite microstructure. An annular array design is considered, spatially it offers axi-symmetric layout while reducing number of array elements, which could potentially result in a significant reduction in the cost and complexity of building an ultrasonic volumetric imaging system. Modelling and preliminary experimental results are presented to evaluate the feasibility of this approach.","PeriodicalId":368182,"journal":{"name":"2009 IEEE International Ultrasonics Symposium","volume":"111 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2009-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115195012","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}