2012 IEEE International Ultrasonics Symposium最新文献

{"title":"Surface contact of bound targeted microbubbles","authors":"K. Kooiman, T. Kokhuis, I. Skachkov, J. Bosch, A. V. D. van der Steen, W. V. van Cappellen, N. de Jong","doi":"10.1109/ULTSYM.2012.0539","DOIUrl":"https://doi.org/10.1109/ULTSYM.2012.0539","url":null,"abstract":"For molecular imaging using ultrasound contrast agents, targeted microbubbles are designed with specific ligands linked to the coated shell. Research is ongoing to determine the binding force of targeted microbubbles and to distinguish bound from unbound targeted microbubbles using ultrasound. For this, the actual surface of the targeted microbubbles that binds to a pathology is important. This study focuses on determining the surface contact of bound targeted microbubbles by fluorescence microscopy. Biotinylated lipid-coated microbubbles (3-7 μm in diameter) with either DSPC or DPPC as the main lipid were targeted to a streptavidin-coated surface. The binding area of targeted microbubbles was found to be 6 ± 4% of the total microbubble surface for microbubbles with DSPC as the main lipid (n=22) and 11 ± 4% for microbubbles with DPPC as the main lipid (n=24). The difference can be explained by the heterogeneous distribution of the ligand for DSPC microbubbles whereas the ligand is homogeneously distributed for DPPC microbubbles. These findings can be used to improve the binding of targeted microbubbles and for the ongoing research to distinguish bound from unbound microbubbles.","PeriodicalId":150948,"journal":{"name":"2012 IEEE International Ultrasonics Symposium","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2012-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130786739","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":"Effects of inclined incidence on ultrasonic testing of a closed crack","authors":"T. Okamoto, K. Kurihara, T. Sugiura","doi":"10.1109/ULTSYM.2012.0361","DOIUrl":"https://doi.org/10.1109/ULTSYM.2012.0361","url":null,"abstract":"Detection and sizing of a closed crack are difficult by the conventional ultrasonic testing, because ultrasonic waves propagate through a closed crack. Recently, the nonlinear ultrasonic testing using superharmonics and/or subharmonics is regarded as a remarkable method of detecting a closed crack. However, the mechanism of subharmonics generation by a closed crack is not clear yet. In this study, we investigated propagation of inclined incident ultrasonic waves through a closed crack and introduced a two-dimensional model with reference of a one-dimensional model which we had introduced in our previous study (Kurihara, et al, 2011). In our experiments, after first finding natural frequencies from frequency response curves, we analyzed received signals obtained under the excitation frequencies twice the natural frequencies, using the Wavelet transformation. From the experimental results, subharmonics generation as well as the natural frequencies were influenced by the incident angles and the compression forces. Considering these results, we introduced a two-dimensional model with nonlinear springs. This model gives us numerical results corresponding with the experimental ones. Consequently, this two-dimensional model can be essential to understand the mechanism of subharmonics generation at a closed crack under inclined incidence of ultrasonic waves.","PeriodicalId":150948,"journal":{"name":"2012 IEEE International Ultrasonics Symposium","volume":"14 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2012-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133803132","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 frame rate ultrasound imaging of human carotid artery dynamics","authors":"P. Kruizinga, F. Mastik, N. de Jong, A. V. D. van der Steen, G. van Soest","doi":"10.1109/ULTSYM.2012.0293","DOIUrl":"https://doi.org/10.1109/ULTSYM.2012.0293","url":null,"abstract":"The carotid artery (CA) is one of the main arteries of interest to cardiovascular research, because of the clinical relevance of CA plaques as culprits of stroke and the accessibility of the CA for cardiovascular health screening. Viscoelastic properties of the arterial wall and of possible lesions within are key components for clinical evaluation of the CA. These viscoelastic properties can be assessed by monitoring the interaction of the wall with a passing arterial pulse wave using ultrasound (US) imaging. The local wall motion (position, velocity, and acceleration) may contain high frequency components and hence a full understanding of tissue mechanics in the CA requires very high frame rate imaging. In this paper we present a high density motion analysis of the CA based on an arterial pulse wave imaged with 2.5 up to 35 kHz frame rate US imaging.","PeriodicalId":150948,"journal":{"name":"2012 IEEE International Ultrasonics Symposium","volume":"2016 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2012-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127266783","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":"Plane wave ultrasound imaging with a broadband photoacoustic source","authors":"P. Kruizinga, B. Cox, N. de Jong, P. Beard, A. V. D. van der Steen, G. van Soest","doi":"10.1109/ULTSYM.2012.0353","DOIUrl":"https://doi.org/10.1109/ULTSYM.2012.0353","url":null,"abstract":"Plane wave ultrasound imaging using a single short, broadband planar source pulse generated by photoacoustic excitation, was demonstrated.","PeriodicalId":150948,"journal":{"name":"2012 IEEE International Ultrasonics Symposium","volume":"21 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2012-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"134137747","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":"Measure elasticity and viscosity using the out-of-plane shear wave","authors":"Heng Zhao, B. Qiang, C. Amador, P. Song, M. Urban, R. Kinnick, J. Greenleaf, Shigao Chen","doi":"10.1109/ULTSYM.2012.0053","DOIUrl":"https://doi.org/10.1109/ULTSYM.2012.0053","url":null,"abstract":"Tissue elasticity μ₁ and viscosity μ₂ can be estimated by evaluating dispersion of shear wave propagation velocity over a range of frequencies. Alternatively, μ₁ and μ₂ can be calculated from shear wave attenuation α_s and velocity c_s at a single frequency. For shear waves generated by a focused ultrasound beam, attenuation due to geometric spreading makes it difficult to estimate as correctly. In this study, we use a wide unfocused beam to generate quasi-planar radiation force (minimal diffraction) and monitor the out-of-plane (elevation direction) shear wave propagation using another transducer. Frequency dependent c_s and α_s values are calculated from the 2D Fourier transform (k-space) of the spatiotemporal shear wave data, using peak extraction and a full-width-of-half-maximum (FWHM) method. Simulation and experiment studies show good agreement between the results using the proposed method and the theoretical or independent measurement results. With the two probes placed on one side of the target or integrated into a 2D array probe, the proposed method could be applied to study in vivo tissue viscoelastic properties.","PeriodicalId":150948,"journal":{"name":"2012 IEEE International Ultrasonics Symposium","volume":"14 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2012-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"121232016","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 axial array for three-dimensional intravascular ultrasound","authors":"E. Alles, G. van Dijk, A. V. D. van der Steen, A. Gisolf, K. V. van Dongen","doi":"10.1109/ULTSYM.2012.0287","DOIUrl":"https://doi.org/10.1109/ULTSYM.2012.0287","url":null,"abstract":"With intravascular ultrasound, high resolution cross-sectional images of arterial walls can be obtained. By pulling a catheter through the artery in the axial direction and stacking consecutive cross-sectional images, a three-dimensional image is obtained. However, cardiac and respiratory motion, combined with a high pull-back rate and a narrow axial radiation pattern, result in poor axial resolution and significant image distortion. To avoid these limitations, in this work the design of an axial linear transducer array is presented with which volumetric rather than cross-sectional images are obtained in every pullback position. The prototype consists of eight elements of dimensions 100 μm by 350 μm, with a kerf of 100 μm, operating at a center frequency of 21 MHz with a bandwidth of more than 80 %. For both an ex vivo bovine artery and a stent-emulating phantom, the image quality in the circumferential and radial directions is similar to that of a conventional catheter. However, in the axial direction a significant increase in image quality is achieved. With the array, it is possible to image both the struts of a stent phantom and the underlying structures, whereas with the conventional catheter the struts are not properly localised and the underlying tissue is not distinguishable from the stent.","PeriodicalId":150948,"journal":{"name":"2012 IEEE International Ultrasonics Symposium","volume":"98 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2012-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"132624690","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":"Guided waves in a helical peripheral strand of a wirerope by electromagnetic acoustic transducers","authors":"Kodai Okazaki, I. Oguma, T. Sugiura","doi":"10.1109/ULTSYM.2012.0676","DOIUrl":"https://doi.org/10.1109/ULTSYM.2012.0676","url":null,"abstract":"Guided waves are propagated in rods and pipes for a long distance without energy loss. Therefore, compared with conventional methods requiring long time, guided waves are ideal for non-destructive testing of wireropes. In this research, aiming to evaluate effects of the geometry of wireropes on guided wave propagation and to generate particular oscillation modes, we carried out experiments and finite element analysis. The results of experiments showed selective excitation of oscillation modes by electromagnetic acoustic transducers and propagation of guided waves along peripheral strands. Numerical results showed slight effect of helical structure on received signals.","PeriodicalId":150948,"journal":{"name":"2012 IEEE International Ultrasonics Symposium","volume":"11 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2012-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128460261","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":"Automatic lipid detection in human coronary atherosclerosis using spectroscopic intravascular photoacoustic imaging","authors":"K. Jansen, A. V. D. van der Steen, H. V. van Beusekom, Geert Springeling, Min Wu, F. Mastik, G. van Soest","doi":"10.1109/ULTSYM.2012.0009","DOIUrl":"https://doi.org/10.1109/ULTSYM.2012.0009","url":null,"abstract":"Lipid content is a key factor in vulnerable atherosclerotic plaques that may lead to myocardial infarction. Intravascular photoacoustic (IVPA) imaging is a possible method to identify lipid content in the artery wall. We developed a method to automatically detect lipids in human coronary atherosclerosis using spectroscopic IVPA. In cross-sectional IVPA/intravascular ultrasound (IVUS) scans of fresh ex vivo human coronary arteries, we correlated the photoacoustic spectra to a reference lipid spectrum in the 1200 nm spectral range. Correlation coeffcients above a certain cut-off value indicated similarity between IVPA and reference lipid spectra. Automatically detected lipid areas exhibited good correspondence with the histological lipid stain of the same cross section.","PeriodicalId":150948,"journal":{"name":"2012 IEEE International Ultrasonics Symposium","volume":"30 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2012-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128128029","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":"Analysis of neovascularization of atherosclerotic carotid plaques in contrast enhanced ultrasound","authors":"Z. Akkus, A. Hoogi, J. Bosch, G. Renaud, S. V. D. Van Den Oord, G. T. ten Kate, A. Schinkel, D. Adam, N. de Jong, A. V. D. van der Steen","doi":"10.1109/ULTSYM.2012.0229","DOIUrl":"https://doi.org/10.1109/ULTSYM.2012.0229","url":null,"abstract":"Intraplaque neovascularization (IPN) is linked to progressive atherosclerotic disease and plaque instability. Contrast enhanced ultrasound (CEUS) can detect these microvessels. Quantification of IPN may allow early detection of vulnerable plaques. We developed a semiautomatic quantification of IPN in CEUS, with motion compensation, contrast spot detection, tracking and classification, and vascular tree reconstruction. Side-by-side CEUS and B-mode carotid images were analyzed (Philips iU22, L9-3 linear array). The plaque motion pattern was obtained from B-mode with block matching (BM) and multidimensional dynamic programming (MDP) and applied to CEUS images for motion correction. In BM, a 6×4mm fixed template was scanned over a 6×2mm search region and normalized correlation coefficients were used in MDP to find the optimal 2D displacement path over time. Image sequences were divided into sets of 10 frames with 80% overlap. In frame 1 of each set, artificial bubble templates detect contrast bubbles within plaque. Templates of 1.3×1.3mm around detected objects were tracked over 10 frames using BM and MDP. Tracks were classified as moving bubbles or artifacts based on their motion. From the overlapping sets, tracks were merged and vessel paths quantified. Automated detection/ tracking / grading of IPN were validated against manual tracking and visual grading by two physicians in 28 plaques. Our algorithm detected 101 of 104 visually identified contrast spots. In 90 of 101 objects (89%), mean error between automated and manual tracking was <; 0.5mm. 81 detected objects (78%) were correctly classified into artifacts and microvessels. Two physicians independently scored plaques into 4 grades of IPN. Automated IPN score was identical to visual scoring in 64%, 1 grade difference in 27% and 2 grades in 9%, which is very comparable to the interobserver differences (68%, 25%, 7%). Our algorithm can successfully detect and track contrast bubbles, classify objects into microvessels and artifacts, and reconstruct microvessel trees. The automated IPN score is equivalent to an expert visual score.","PeriodicalId":150948,"journal":{"name":"2012 IEEE International Ultrasonics Symposium","volume":"60 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2012-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116974539","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":"Characterizing ultrasound-controlled drug release by high-speed fluorescence imaging","authors":"Y. Luan, E. Gelderblom, G. Lajoinie, I. Skachkov, H. Dewitte, B. Geers, I. Lentacker, T. van der Steen, M. Versluis, N. de Jong","doi":"10.1109/ULTSYM.2012.0510","DOIUrl":"https://doi.org/10.1109/ULTSYM.2012.0510","url":null,"abstract":"Ultrasound contrast agents (UCAs) microbubbles (MBs) can be preloaded with a therapeutic agents to achieve high efficiency for US-triggered drug delivery. Here we use fluorescence labeling as a substitute for theraputic drug, and use ultra high-speed fluorescence imaging for time-resolved observation of the drug release. Two configurations of drug delivery vehicles were investigated - I) lipid-shelled (unloaded) MBs and II) liposome-loaded (loaded) MBs. Different release phenomena were observed. The dynamics of release was found to be strongly dependent on ultrasonic parameters and on the MB's shell properties. MBs shrinkage following US exposure was analyzed and it indicated close correlation with the fluorescence release. This study provides valuable insights into the drug release mechanisms for ultrasound-controlled drug delivery.","PeriodicalId":150948,"journal":{"name":"2012 IEEE International Ultrasonics Symposium","volume":"48 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2012-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115591599","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}