V. Mathieu, K. Fukui, Mami Mastukawa, M. Kawabe, F. Anagnostou, E. Soffer, G. Haiat
{"title":"Assessment of the biomechanical properties of newly formed bone tissue using micro-Brillouin scattering","authors":"V. Mathieu, K. Fukui, Mami Mastukawa, M. Kawabe, F. Anagnostou, E. Soffer, G. Haiat","doi":"10.1109/ULTSYM.2010.5935895","DOIUrl":"https://doi.org/10.1109/ULTSYM.2010.5935895","url":null,"abstract":"The assessment of implant stability in bone tissue remains difficult because remodelling phenomena in the vicinity of the implant are still poorly understood. The present multimodality study investigates the potentiality of micro-Brillouin scattering technique to differentiate mature and newly formed bone microscopic elastic properties following an approach coupled with histological analysis. Coin-shaped Ti-6Al-4V implants were placed in vivo in rabbit tibia. After seven weeks of implantation, bone samples were removed, embedded in methyl methacrylate and sliced into 190 µm thick sections. A micro-Brillouin scattering technique was used to measure ultrasonic velocities in 10 µm diameter regions located in mature and newly formed bone. The same section was then stained for histological analysis of the mineral content of the bone sample. The mean values of the ultrasonic velocities were equal to 4.98 10−3 m/s in newly formed bone tissue and 5.20 10−3 m/s in mature bone. ANOVA (p=0.029) tests revealed significant differences between the two groups of measurements. Histological observations showed a lower degree of mineralization in newly formed bone than in mature cortical bone. The higher ultrasonic velocity measured in newly formed bone tissue compared to mature bone might be explained by the higher mineral content in mature bone, which was confirmed by histology. The results demonstrate the feasibility of micro-Brillouin scattering measurements to investigate the elastic properties of newly formed bone tissue.","PeriodicalId":6437,"journal":{"name":"2010 IEEE International Ultrasonics Symposium","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2010-10-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"78029845","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}
Man Zhang, M. Fabiilli, P. Carson, F. Padilla, S. Swanson, O. Kripfgans, B. Fowlkes
{"title":"Acoustic droplet vaporization for the enhancement of ultrasound thermal therapy","authors":"Man Zhang, M. Fabiilli, P. Carson, F. Padilla, S. Swanson, O. Kripfgans, B. Fowlkes","doi":"10.1109/ULTSYM.2010.5935861","DOIUrl":"https://doi.org/10.1109/ULTSYM.2010.5935861","url":null,"abstract":"Acoustic droplet vaporization (ADV) is an ultrasound method for converting biocompatible microdroplets into microbubbles. The objective is to demonstrate that ADV bubbles can enhance high intensity focused ultrasound (HIFU) therapy by controlling and increasing energy absorption at the focus. Thermal phantoms were made with or without droplets. Compound lesions were formed in the phantoms by 5-second exposures with 5-second delays. Center to center spacing of individual lesions was 5.5 mm in either a linear pattern or a spiral pattern. Prior to the HIFU, 10 cycle tone bursts with 0.25% duty cycle were used to vaporize the droplets, forming an “acoustic trench” within 30 seconds. The transducer was then focused in the middle of the back bubble wall to form thermal lesions in the trench. All lesions were imaged optically and with 2T MRI. With the use of ADV and the acoustic trench, a uniform thermal ablation volume of 15 cm3 was achieved in 4 minutes; without ADV only less than 15% of this volume was filled. The commonly seen tadpole shape characteristic of bubble-enhanced HIFU lesions was not evident with the acoustic trench. In conclusion, ADV shows promise for the spatial control and dramatic acceleration of thermal lesion production by HIFU.","PeriodicalId":6437,"journal":{"name":"2010 IEEE International Ultrasonics Symposium","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2010-10-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"87901930","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}
S. Ménigot, I. Voicu, A. Novell, M. E. H. Amar, J. Girault
{"title":"Adaptive matched filters for contrast imaging","authors":"S. Ménigot, I. Voicu, A. Novell, M. E. H. Amar, J. Girault","doi":"10.1109/ULTSYM.2010.5935573","DOIUrl":"https://doi.org/10.1109/ULTSYM.2010.5935573","url":null,"abstract":"The ultrasound (US) contrast imaging is a promising technique. Currently the scientific community of this field seeks US excitations which should make possible the optimization of the acoustic contrast. Two matched filters (MF) techniques are used to improve the image contrast. The first technique is an adaptive MF technique and the second is a RLS technique derived from identification theory. The system proposed is a close loop system which optimizes the power backscattered by microbubbles. After having transmit a first signal, the backscattered power is optimized by transmitting the matched filtered signal at each iteration. This process is iterated until convergence. Simulations are carried out for encapsulated microbubbles of 2 microns by considering the modified Rayleigh-Plesset equation for a 2.25MHz transmitted frequency and for various pressure levels (20 kPa up to 420kPa). In vitro, experiments are carried out by using two transducers a transducers which were placed perpendicularly. The signal was transmitted through a 2.25 MHz transducer. Responses of a 1/2000 diluted solution of SonoVue™ were measured by a 3.5 MHz transducer. Each experiment has been realized with three pressure levels (127, 244 and 370 kPa). We show through simulations and through in vitro experiments that our adaptive imaging technique gives in case of simulations a gain which can reach 12 dB compared to the traditional technique and for in vitro experiments, the MF gives a gain which can reach 4.5 dB whereas the MF derived from identification theory can reach 6 dB.","PeriodicalId":6437,"journal":{"name":"2010 IEEE International Ultrasonics Symposium","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2010-10-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"90863523","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 dispersion of solidly mounted resonators with an optimized reflector stack for dual wave reflection","authors":"S. Jose, R. Hueting, A. Jansman","doi":"10.1109/ULTSYM.2010.5935642","DOIUrl":"https://doi.org/10.1109/ULTSYM.2010.5935642","url":null,"abstract":"Spurious resonance suppression in Bulk Acoustic Wave (BAW) resonators is essential for achieving excellent filter characteristics. These spurious resonances are undesired resonances caused by the finite device edges. The type I mode is the preferred dispersion response for \"spurious modes\" suppression, since it allows for the direct use of the frame region as the edge termination of the device. In this work we present a novel analytical approach to adjust the dispersion response in a desired way for various material combinations. By employing the diffraction grating method (DGM), which provides dual wave reflection after tailoring the layer stack thickness analytically, we obtain a type I dispersion curve despite the use of a type II piezoelectric material for the resonator. The dispersion response was verified from analytical impedance curves and FEM simulations. The reason for this type of response can be the inherent thicker top-oxide layer. A transmission of −37dB is maintained for longitudinal waves whereas shear waves reach value below −22 dB for a five layer SiO2/W stack, while for a three layer SiOC/Pt (935/555nm) stack −36dB and −24dB is obtained, respectively.","PeriodicalId":6437,"journal":{"name":"2010 IEEE International Ultrasonics Symposium","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2010-10-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"73769537","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}
P. Carson, Boyun Wang, G. LeCarpentier, M. Goodsitt, Chris Lashbrook, Renee Pinsky, G. Narayanasamy, J. Fowlkes, K. Saitou
{"title":"Local compression in automated breast ultrasound in the mammographic geometry","authors":"P. Carson, Boyun Wang, G. LeCarpentier, M. Goodsitt, Chris Lashbrook, Renee Pinsky, G. Narayanasamy, J. Fowlkes, K. Saitou","doi":"10.1109/ULTSYM.2010.5935830","DOIUrl":"https://doi.org/10.1109/ULTSYM.2010.5935830","url":null,"abstract":"Background, Motivation and Objective: Automated ultrasound scanning (AUS) of the breast has developed more slowly than anticipated. The main limitation, beyond achieving adequate acoustic coupling to the breast, has been excessive shadow artifacts, as reflecting structures at acute angles to the ultrasound beam are not flattened by the transducer as well as in manual scanning. We believe that imaging of the breast in near mammographic compression provides much of the needed flattening. The question under initial study in this effort is, whether in breast AUS under very light mammographic compression, local compression by the transducer might flatten the acutely oriented structures further and reduce the acoustic path length to key structures in the breast. We suspect these improvements will be possible without distorting the breast so dramatically that the lesion registration advantages of scanning the breast in the same system as mammography or digital breast tomosynthesis (DBT) are not realized. Preliminary tests are reported here, as well as design of a system for a more refined human study. Statement of Contribution/Methods: Initial imaging tests were performed in our combined AUS/DBT system. A fiber mesh, loosened slightly in its frame, replaced the standard plastic mammography compression paddle. The transducer, in contact with the mesh and the breast, was translated by motors. The compression force of the linear array transducer on its vertical was manually controlled. Breast phantoms and the breasts of three women were scanned with usual compression by the mesh paddle and then with less global, but added local, compression. Results: Examples of flattened structures were observed more brightly in the locally compressed breasts, and acoustic paths longer than 35 mm were reduced, by ∼10 mm. In many areas image penetration was 3 cm greater. In one case, image volumes w/wo local compression were spatially aligned by nonlinear image registration software. Discussion and Conclusions: Visual indicators of image features expected to provide improved ultrasonic imaging were observed with local compression and lateral movement of tissues appeared acceptable. These results motivated design and construction of an apparatus to make local compression practical and safe. It utilizes joystick control of the vertical compression force during scanning, realized by pneumatic actuators attached to the transducer. The air pressure applied to these actuators is also applied to actuators in the joystick for force feedback to the operator. Two miniature vibrators attached to the joystick provide vibrotactile feedback of the reaction torques computed from the measurements of 6 force sensors on the transducer holder. The fail-safe system design insures no pneumatic compression force application to the breast in case of power loss or emergency shutdown.","PeriodicalId":6437,"journal":{"name":"2010 IEEE International Ultrasonics Symposium","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2010-10-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"86714488","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}
Patrick H. Johnston, C. Wright, Joseph N. Zalameda, Jeffrey P. Seebo
{"title":"Ultrasonic monitoring of ply crack and delamination formation in composite tube under torsion load","authors":"Patrick H. Johnston, C. Wright, Joseph N. Zalameda, Jeffrey P. Seebo","doi":"10.1109/ULTSYM.2010.5935887","DOIUrl":"https://doi.org/10.1109/ULTSYM.2010.5935887","url":null,"abstract":"As a simple model of a rotor spar, a circular graphite-epoxy composite laminate cylinder was subjected to cyclic torsional load. The test section of the cylindrical specimen varied from four to six plies of ±45° fibers, due to intentional ply overlaps and gaps. A layer of 13-μm Teflon film was inserted between plies at three locations to serve as delamination initiators. A commercial X-Y scanner was mounted to the load frame to enable ultrasonic inspection without removing the specimen. A focused immersion probe was mounted in a captive water column with a rugged Nitrile membrane tip, which was coupled to the cylinder using a mist of soapy water. The transducer was aligned normal to the cylinder surface using the X-axis. Scanning was performed along the length of the specimen with the Y-axis and the specimen was incrementally rotated by the torsion head of the load frame. After 350k cycles of torsion, several linear 45° diagonal indications appeared as 5–40% attenuation of the back wall echo, with no apparent echoes from the interior of the composite, suggesting through-ply cracks in the innermost ply. Crack indications grew and new cracks appeared as torsion cycling continued. Internal reflections from delaminations associated with the growing ply cracks appeared after 500k cycles. Three areas of extensive multi-layer delaminations appeared after 1150k cycles. Failure of the specimen occurred at 1600k cycles. The observed progressive damage was not associated with the Teflon inclusions. Concurrent thermographic measurements provided lower-resolution confirmation of the damage observed.","PeriodicalId":6437,"journal":{"name":"2010 IEEE International Ultrasonics Symposium","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2010-10-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"84482710","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}
L. Francalanci, A. Dallai, P. Tortoli, C. Palombo, L. Ghiadoni
{"title":"Simultaneous measurement of wall shear stress and arterial distension in FMD studies","authors":"L. Francalanci, A. Dallai, P. Tortoli, C. Palombo, L. Ghiadoni","doi":"10.1109/ULTSYM.2010.5935468","DOIUrl":"https://doi.org/10.1109/ULTSYM.2010.5935468","url":null,"abstract":"In Flow-mediated dilation (FMD) studies, blood flow in the brachial artery is restricted for about 5 minutes by a cuff. When the restriction is removed, the subsequent increase in wall shear rate (WSR) stimulates the release of nitric oxide, a vasodilator, from the endothelial cells into the smooth muscle. Impaired FMD responses, which are considered independent predictors of possible cardiovascular events, should be reliably detected. While several efforts have been so far dedicated to measure the diameter change, the source of this change, i.e., the WSR increase, has not been measured so far. In this paper, first results of the simultaneous measurement of WSR and diameter performed during FMD studies in the brachial arteries of 15 volunteers are reported. All measurements were obtained through the ULtrasound Advanced Open Platform (ULA-OP).","PeriodicalId":6437,"journal":{"name":"2010 IEEE International Ultrasonics Symposium","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2010-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"73494474","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":"Visualization in propagation of electric excitation in human heart","authors":"H. Kanai","doi":"10.1109/ULTSYM.2010.5935547","DOIUrl":"https://doi.org/10.1109/ULTSYM.2010.5935547","url":null,"abstract":"Conventional echocardiography visualizes cross-sectional images, motion, and torsional deformation during contraction of the heart. However, it is restricted to static configurations or large and slow motion. We have previously found that minute pulsive vibration occurs just after electrical stimulation of the extracted papillary muscle of a rat [Acoust Sci & Tech 2003;24:17]. By applying a novel ultrasound-based method [IEEE UFFC 1997;44:752] to human hearts, we were able to successfully measure the spontaneous response of the myocardium to electrical excitation [UMB 2009;35:936]. In the present study, we visualize the propagation of the myocardial response of the electric excitation in human hearts during systole. In the parasternal short-axis view of the left ventricle (LV), the RF reflective wave along each ultrasonic beam was acquired. The number of directions of the ultrasonic transmission was restricted to 16 to maintain a high frame rate (500 Hz), and then at all of about 25,000 points set in the heart wall, the velocity components toward the ultrasonic probe were simultaneously obtained as waveforms, and their instantaneous phases of 40-Hz components were color-coded (red: come close to). The instantaneous distribution of the phase was rearranged along the circumferential direction and set in an array consecutively at every 2 ms from the time of P-wave of the ECG, precisely revealing the propagation of the velocity components in the LV circumferential direction. This novel method was applied to healthy subjects. A velocity component corresponding to the contraction was generated at the septum at a time of R-wave of ECG, and propagated slowly (0.4 m/s) in clockwise direction along the LV circumferential direction. On the other hand, just from each radiation time of the first and second heart sounds, mechanical shear was generated at the septum and propagated in counterclockwise direction. These phenomena were observed for other subjects. The propagation of the contraction will correspond to one of the layers consisting of the LV. The subtle dynamic response of the myocardium to the arrival of the electrical stimulation accurately measured in the present study will show a potential for noninvasive assessment of myocardial damage due to heart failure.","PeriodicalId":6437,"journal":{"name":"2010 IEEE International Ultrasonics Symposium","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2010-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"73840596","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":"Cytoplasmic signaling involved in sonoporation-induced apoptosis and mitosis repression of myeloid leukemia cells","authors":"W. Zhong, W. Sit, J. Wan, A. Yu","doi":"10.1109/ULTSYM.2010.5935545","DOIUrl":"https://doi.org/10.1109/ULTSYM.2010.5935545","url":null,"abstract":"Sonoporation is known to be a transient phenomenon that may disrupt the homeostasis of living cells. In this work, we showed that sonoporation may bear time-lapse impact on cellular viability through up-regulation of cytoplasmic signaling proteins related to apoptosis and cell-cycle arrest. Our experiments were done on HL-60 leukemia cells (106 cells/ml), and sonoporation was induced via the use of 1% v/v microbubbles and 1-min. pulsed ultrasound exposure (0.5MPa peak negative pressure, 1MHz center frequency, 10% duty cycle, 1 kHz pulse repetition frequency). The transient nature of sonoporation in these cells was confirmed by performing scanning electron microscopy on selected cell samples that were fixed respectively after a few seconds into the ultrasound exposure and one minute after the end of exposure. Cytoplasmic signaling changes of these cells were studied at four post-sonoporation time points (4h, 8h, 12h, 24h) using western blot analysis. Five signaling proteins related to apoptosis and mitosis were analyzed in this work: 1) PARP (for DNA repair); 2) cleaved-PARP (fragments due to cleavage by pro-apoptotic caspase proteins); 3) Bcl-2 (inhibitor for mitochrondrial release of pro-apoptotic molecules); 4) Bax (complement of Bcl-2); 5) Cdc-2 (regulator for cell mitosis). Three key results were found from the cytoplasmic signaling analysis. First, PARP levels were reduced over the monitoring period whilst cleaved-PARP had increased in expression, and in turn they indicate that the cells' anti-apoptotic responses were dampened following sonoporation and pro-apoptotic caspase proteins were likely activated. Second, drop in Bcl-2 and rise in Bax were observed, and these suggest that the mitochondrion was involved in apoptotic signal transduction inside sonoporated cells. Third, Cdc-2 was seen to decrease, implying that mitosis was repressed in sonoporated cells.","PeriodicalId":6437,"journal":{"name":"2010 IEEE International Ultrasonics Symposium","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2010-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"74072057","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":"Ultrasound generated mechanical induction of mesenchymal stem cells","authors":"Jia‐Ling Ruan, Yak-Nam Wang, L. Crum, S. Mitchell","doi":"10.1109/ULTSYM.2010.5935957","DOIUrl":"https://doi.org/10.1109/ULTSYM.2010.5935957","url":null,"abstract":"The hypothesis of this research is that ultrasound (US) can induce stem cell activity. Specifically, the aim for this study is to optimize the mechanical effect generated by US for the stimulation of mesenchymal stem cells (MSCs). MSCs were cultured on flexible membrane culture plates and stimulated by US for 10 min daily with acoustic intensity of 0, 6, 13.5, and 22.5 W/cm2 (control, P1, P2, and P3 respectively). Cell proliferation and viability were evaluated by direct cell count and Alamar Blue assay. Morphological evaluation was also performed. Cell-matrix interaction was analyzed by immunochemical staining of focal adhesion proteins. Our preliminary results showed that P2 and P3 groups had a better performance in cell proliferation compared to the results of P1 and control, and there was also an increase in cell viability from the Alamar Blue test after 4 consecutive days of US treatment (P2 vs. control). Although no morphological change was observed, expression of focal adhesion protein, vinculin, was enhanced after three consecutive days of US treatment (P3 vs. control). The conclusion is application of higher acoustic pressure on cell growth environment can stimulate MSC proliferation and focal adhesion. However, further studies are required to optimize the acoustic parameters.","PeriodicalId":6437,"journal":{"name":"2010 IEEE International Ultrasonics Symposium","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2010-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"72778356","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}