2009 IEEE International Ultrasonics Symposium最新文献_第4页

Tracking the endocardial border in artifact-prone 3D images 在容易产生伪影的3D图像中跟踪心内膜边界

2009 IEEE International Ultrasonics Symposium Pub Date : 2009-09-20 DOI: 10.1109/ULTSYM.2009.5442017

K. Leung, M. Danilouchkine, M. van Stralen, N. de Jong, A. V. D. van der Steen, J. Bosch

{"title":"Tracking the endocardial border in artifact-prone 3D images","authors":"K. Leung, M. Danilouchkine, M. van Stralen, N. de Jong, A. V. D. van der Steen, J. Bosch","doi":"10.1109/ULTSYM.2009.5442017","DOIUrl":"https://doi.org/10.1109/ULTSYM.2009.5442017","url":null,"abstract":"Echocardiography is a commonly-used, safe, and noninvasive method for assessing cardiac dysfunction and related coronary artery disease. The analysis of echocardiograms, whether visual or automated, has traditionally been hampered by the presence of ultrasound artifacts, which obscure the moving myocardial wall. In this study, a novel method is proposed for tracking the endocardial surface in 3D ultrasound images. Artifacts which obscure the myocardium are detected in order to improve the quality of cardiac boundary segmentation. The expectation-maximization algorithm is applied in a stationary and dynamic, cardiac-motion frame-of-reference, and weights are derived accordingly. The weights are integrated with an optical-flow based contour tracking method, which incorporates prior knowledge via a statistical model of cardiac motion. Evaluation on 35 three-dimensional echocardiographic sequences shows that this weighed tracking method significantly improves the tracking results. In conclusion, the proposed weights are able to reduce the influence of artifacts, resulting in a more accurate quantitative analysis.","PeriodicalId":368182,"journal":{"name":"2009 IEEE International Ultrasonics Symposium","volume":"35 5 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":"132352038","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}

引用次数: 0

Design of a micro-beamformer for a 2D piezoelectric ultrasound transducer 二维压电超声换能器微波束形成器的设计

2009 IEEE International Ultrasonics Symposium Pub Date : 2009-09-20 DOI: 10.1109/ULTSYM.2009.5441534

S. Blaak, Z. Yu, G. Meijer, C. Prins, C. Lancée, J. Bosch, N. de Jong

引用次数: 51

Automatic detection of microemboli by means of a synchronous linear prediction technique 用同步线性预测技术自动检测微栓子

2009 IEEE International Ultrasonics Symposium Pub Date : 2009-09-20 DOI: 10.1109/ULTSYM.2009.5441701

S. Ménigot, Latifa Dreibine, Nawal Meziati, J. Girault

{"title":"Automatic detection of microemboli by means of a synchronous linear prediction technique","authors":"S. Ménigot, Latifa Dreibine, Nawal Meziati, J. Girault","doi":"10.1109/ULTSYM.2009.5441701","DOIUrl":"https://doi.org/10.1109/ULTSYM.2009.5441701","url":null,"abstract":"Detection of microemboli is of great clinical importance to prevent cerebro-vascular events and to identify the causes of such events. As standard detection techniques implemented in the most commonly used systems cannot detect all of microemboli events whose energy is lower than the systolic energy, new techniques are proposed. By assuming that the Doppler signal is cyclostationary, we hypothesize that energy is statistically periodic. Furthermore, we hypothesis that embolic signals are unpredictable. Hence, the joint use of synchronous and linear prediction techniques could detect very small microemboli. If we periodically take and compare the values of the energy of the prediction error (or autoregressive parameters) at different time points in the cardiac cycle, we can therefore detect the presence of non-periodic events such as microemboli. In our study, we tested and compared our new technique to the standard technique (Fourier) using simulated and in vivo signals from patients with stenosis of high degrees of severity. From simulations, the standard automatic technique detected 60% of microemboli detected by our gold standard technique (audible detection and sonogram visualization) whereas the synchronous linear prediction technique detects 97% (the false alarm rate being set at 0%). From clinic examinations, the standard automatic technique only detects 67% of microemboli detected by our gold standard technique whereas the synchronous linear prediction technique detected 100%. This study demonstrates that our new technique detects microemboli up to now not identified by classical methods. Large microemboli are all detected, but small microemboli are only detected with our new technique. This latter technique opens up new prospects to detect small emboli, despite the need for further studies to incorporate \"on line\" technique.","PeriodicalId":368182,"journal":{"name":"2009 IEEE International Ultrasonics Symposium","volume":"39 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":"115164380","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}

引用次数: 9

Beamspace transformation for data reduction using genetic algorithms 用遗传算法进行数据约简的波束空间变换

2009 IEEE International Ultrasonics Symposium Pub Date : 2009-09-20 DOI: 10.1109/ULTSYM.2009.5442004

Minghui Li, K. S. Ho, G. Hayward

引用次数: 10

An acoustic waveguide using doubly-bonded silicon/thinned PPT/silicon structures for RF applications 一种用于射频应用的双键硅/薄PPT/硅结构声波导

2009 IEEE International Ultrasonics Symposium Pub Date : 2009-09-20 DOI: 10.1109/ULTSYM.2009.5441895

F. Bassignot, E. Courjon, G. Ulliac, T. Laroche, J. Garcia, S. Queste, J. Romand, S. Ballandras, R. Petit

引用次数: 2

Improvement of the power response in contrast imaging with transmit frequency optimization 利用发射频率优化提高对比成像功率响应

2009 IEEE International Ultrasonics Symposium Pub Date : 2009-09-20 DOI: 10.1109/ULTSYM.2009.5441554

S. Ménigot, A. Novell, A. Bouakaz, J. Girault

{"title":"Improvement of the power response in contrast imaging with transmit frequency optimization","authors":"S. Ménigot, A. Novell, A. Bouakaz, J. Girault","doi":"10.1109/ULTSYM.2009.5441554","DOIUrl":"https://doi.org/10.1109/ULTSYM.2009.5441554","url":null,"abstract":"Conventionnal ultrasound contrast imaging systems use a fixed transmit frequency. However it is known that the insonified medium (microbubbles) is time-varying and therefore an adapted time-varying excitation is expected. We suggest an adaptive imaging technique which selects the optimal transmit frequency that maximizes the contrast tissue ratio (CTR). Two algorithms have been proposed to find an US excitation for which the frequency has been optimal with microbubbles. Simulations were carried out for encapsulated microbubbles of 2 ¿m-radius by considering the modified Rayleigh-Plesset equation for a 2.25 MHz transmitted frequency and for various pressure levels (20 kPa up to 420 kPa). In vitro experiments have been carried out using a 2.25 MHz transducer and using a programmable waveform generator. Responses of a 1/2000 blood mimicking fluid-diluted solution of Sonovue¿ were measured by a 3.5 MHz transducer. We show through simulations that our adaptive imaging technique allows to reduce the transmit maximal pressure. As for in vitro experiments the CTR can reach 10 dB. By proposing a close loop system whose frequency adapts itself with the perfused media, throughout the examination, the optimization system adapt itself to the remaining bubbles population thus allowing an increase of the 30% examination duration.","PeriodicalId":368182,"journal":{"name":"2009 IEEE International Ultrasonics Symposium","volume":"53 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":"116214541","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}

引用次数: 6

Nonlinear and von neumann reflection of elastic shock waves in soft solids 弹性激波在软固体中的非线性和冯诺依曼反射

2009 IEEE International Ultrasonics Symposium Pub Date : 2009-09-01 DOI: 10.1109/ULTSYM.2009.5441623

G. Pinton, F. Coulouvrat, J. Gennisson, M. Tanter

引用次数: 1

Characterization of mamterial properties in solid oxide fuel cells using a laser ultrasound technique 用激光超声技术表征固体氧化物燃料电池的材料特性

2009 IEEE International Ultrasonics Symposium Pub Date : 2009-09-01 DOI: 10.1109/ULTSYM.2009.5441527

Che-Hua Yang, Sheng‐wei Tang

引用次数: 0

A 2D Ultrasonic array design incorporating hexagonal-shaped elements and triangular-cut piezocomposite substructure for NDE applications 基于六边形单元和三角切割的压电复合材料子结构的二维超声阵列设计

2009 IEEE International Ultrasonics Symposium Pub Date : 2009-09-01 DOI: 10.1109/ULTSYM.2009.5441447

J. Dziewierz, S. Ramadas, A. Gachagan, R. O’Leary, G. Hayward

引用次数: 4

Ultrasound Current Source Density Imaging of a time-varying current field in a multielectrode nerve chamber 多电极神经腔内时变电流场的超声电流源密度成像

2009 IEEE International Ultrasonics Symposium Pub Date : 2009-09-01 DOI: 10.1109/ULTSYM.2009.5441400

R. Olafsson, Qian Li, Zhaohui Wang, P. Ingram, R. Witte

引用次数: 7