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Showing papers in "IEEE Transactions on Sonics and Ultrasonics in 1984"


Journal ArticleDOI
TL;DR: The objective of this paper is to summarize the data on tumor blood flow rate during normothermia and hyperthermia, and to discuss the use of pharmacological agents in modifying the tumorBlood flow rate for therapeutic benefits.
Abstract: Abstruct-The differential blood flow rateof normaland tumor tissues plays a critical role in determining the effectiveness of hyperthermia alone or in combination with radiation and chemotherapy. The objective of this paper is to summarize the data on tumor blood flow rate during normothermia and hyperthermia, and to discuss the use of pharmacological agents in modifying the tumor blood flow rate for therapeutic benefits. After a brief review of various physical, physiological, biochemical, and biological factors that determine the effectiveness of hyperthermia in cancer treatment, various methods of blood flow measurements will be outlined. The following section will be devoted to the tumor blood flow rate during normothermia. Next will be discussion of changes in tumor blood flow rate at elevated temperatures. Finally, the possibility of modifying tumor blood flow rate by the use of vasoactive agents will be discussed. Throughout this paper, outstanding problems in the measurements and alterations of blood flow will be identified and some directions for future research will be suggested.

240 citations


Journal ArticleDOI
TL;DR: Results obtained from analysis of digitized ultrasonic wave- forms backscattered from the livers of normal volunteers and patients with diffuse liver disease and from the spleens of normal Volunteers and Patients with Hodgkin's disease indicate that the "mean scatterer spacing" gives useful information about the state of disease or health of tissue interrogated by an ultrasound beam.
Abstract: Tissue characterization attempts to provide quantitative information about the state of disease or health of tissue interrogated by an ultrasound beam. A notable feature of diffuse disease processes of the liver and spleen is disuption of the normal tissue architecture. Infiitration by collagenous tissue changes both the histologic features and acoustic properties of the tissue. A model is presented for these changes as a change in the distribution of scattering elements and a technique for estimating this distribution from analysis of the fre- quency spectrum of the ultrasonic echoes returned from tissue is de- scribed. Results obtained from analysis of digitized ultrasonic wave- forms backscattered from the livers of normal volunteers and patients with diffuse liver disease and from the spleens of normal volunteers and patients with Hodgkin's disease indicate that the "mean scatterer spacing," determined from this analysis, gives useful information re- lated to histological features that is not available from the ultrasonic image and, in some cases, can provide a valuable discrimination be- tween normal and abnormal tissue.

174 citations


Journal ArticleDOI
TL;DR: In this article, les effets de la diffraction accentuent les limitations dans les mesures utilisant la methode par echo-impulsion and comment ces limitations peuvent etre surmontees for des transducteurs avec ou sans focalisation.
Abstract: On etudie comment les effets de la diffraction accentuent les limitations dans les mesures utilisant la methode par echo-impulsion et comment ces limitations peuvent etre surmontees pour des transducteurs avec ou sans focalisation

143 citations


Journal ArticleDOI
TL;DR: In this article, the authors utilise l'optique des rayons for developper des expressions analytiques simples donnant la variation V(z) de la tension de sortie en fonction du deplacement z de la surface de l'objet par rapport au plan focal.
Abstract: On utilise l'optique des rayons pour developper des expressions analytiques simples donnant la variation V(z) de la tension de sortie en fonction du deplacement z de la surface de l'objet par rapport au plan focal

133 citations


Journal ArticleDOI
TL;DR: Clinical results involving the application of ultrasonic hyperthermia alone, and in conjuction with chemotherapy and radiation in 215 patients are reported, with particular encouragement was the treatment of advanced primary breast cancer with ultrasound combined with chemotherapy, where the first seven patients exhibited a 100 percent overall response rate to therapy.
Abstract: Absmct-Despite the interest in hyperthermia and the rather significant advantages that ultrasound possesses over other methods for localized heating, there remain only a few reports of human studies with welldocumented thermal dosimetry that permit the evaluation of the antitumor efficacy of ultrasound treatment. In this paper, these reports are discussed, and the biological basis for the application of ultrasound hyperthermia as an antitumor modality is presented. Further, clinical results involving the application of ultrasonic hyperthermia alone, and in conjuction with chemotherapy and radiation in 215 patients are reported. Overall objective response rates for ultrasoundalone,ultrasound with chemotherapy, and ultrasound with radiation therapy were 45 percent, 60 percent, and 66 percent, respectively. Of particular encouragement was the treatment of advanced primary breast cancer with ultrasoundcombined withchemotherapy, wherethe first seven wesexhibited a 100 percent overall response rate to therapy.

124 citations



Journal ArticleDOI
TL;DR: In this paper, a method for the solution of the fundamental symmetric Lamb wave in an elastic plate waveguide is described, which is a combination of the finite element and the analytical method.
Abstract: Absfrucf-A method ol the solution of scattering of the fundamental symmetric Lamb wave in an elastic plate waveguide is described. The approach is a combination of the finite-element and the analytical method. The numerical examples on the scattering by a wedge-shaped internal crack and a wedge-shaped surface crack in a plate are given. The reflection coefficient of the internal crack is considerably influenced by the wedge apex angle and the resonance phenomena arise in the region of the crack. On the other hand, the reflection coefficient of the surface crack is not very much affected by the wedge apex angle. The validity of the method is confirmed by comparing numerical results for an infinitely thin internal crack normal to the surface of a plate with the results of the variational method.

116 citations


Journal ArticleDOI
TL;DR: On decrit un systeme de formation d'image acoustique numerique en temps reel capable of reconstruire plus de 30 nouvelles images par seconde (appele DAISY).
Abstract: On decrit un systeme de formation d'image acoustique numerique en temps reel (appele DAISY) capable de reconstruire plus de 30 nouvelles images par seconde. Effets des erreurs de quantification dans les systemes de formation d'image numeriques

101 citations


Journal ArticleDOI
TL;DR: On distingue 2 problemes dans le traitement du signal; le premier concerne la reconstruction d'une image a partir de donnees mesurees transformees de facon appropriee qui echantillonnent le plan de frequences spatiale le long d'arcs circulaires; le second problemme est celui de desenroulement de phase des profils mesures as mentioned in this paper.
Abstract: On distingue 2 problemes dans le traitement du signal; le premier concerne la reconstruction d'une image a partir de donnees mesurees transformees de facon appropriee qui echantillonnent le plan de frequences spatiale le long d'arcs circulaires; le second probleme est celui de desenroulement de phase des profils mesures

80 citations


Journal ArticleDOI
TL;DR: In this paper, the authors present three techniques d'imagerie clefs: representation d'intensite, imagerie par une methode d'echo-impulsion and methodes de phase-amplitude comprenant l'holographie and la tomographie.
Abstract: Historique de l'imagerie acoustique. On presente 3 techniques d'imagerie clefs: representation d'intensite, imagerie par une methode d'echo-impulsion et methodes de phase-amplitude comprenant l'holographie et la tomographie. Discussion sur la resolution et le bruit

76 citations


Journal ArticleDOI
TL;DR: In this article, a new tomographic imaging technique is presented that requires only two rotational positions of an object, where the data is collected most efficiently by using arrays on both the transmit and the receive sides.
Abstract: A new tomographic imaging technique is presented that requires only two rotational positions of an object. Although ideally the angle between the two rotational positions should be 90°, theory predicts that valid results should be obtainable, albeit with reduced spatial resolution, even when this condition is not satisfied. For each rotational position of the object, the data is collected most efficiently by using arrays on both the transmit and the receive sides; the elements of the transmit array are fired sequentially, and for each such firing the received field is measured over all the elements of the receive array. It is shown thot this measurement strotegy firrs up the Fourier space, from which the object can be recovered by simple Fourier inversion. This imaging strategy was derived from the equations of propagation in an inhomogeneous medium with Born and Rytov approximations. A digital implementation is also presented of the proposed algorithm that requires no interpolations in either the frequency or the space domain, and can be carried out with only 2N FFT's for reconstructing an N X Nimage. Since no interpolations are carried out whatsoever, no computational errors are introduced by the algorithm itself. The total computational complexity of the procedure is of the order of Ow3) as compared to O(Ar4) for a filtered-backpropagation algorithm and O(NZ log N) for procedures based on interpolation in the frequency domain. Some computer simulation results have been included to demonstrate the numerical accuracy of the algorithm.

Journal ArticleDOI
TL;DR: A theoretical model developed to compute the spatiotemporal features of temperature rises induced in ocular tissue during exposure to high-intensity focused ultrasound indicates that tumor regression can be achieved at levels that are consistent with damage integral predictions.
Abstract: Absfrucct-A theoretical model was developed to compute the spatiotemporal features of temperature rises induced in ocular tissue during exposure to high-intensity focused ultrasound The model incorporates damage integral evaluation to predict the Occurrence and dimensions of thermally induced lesions Experimental data confirmed the accuracy of computed lesion dimensions for scleral and chorioretinal lesions Computed results also are in agreement with measured threshold exposure levels needed to produce minimal chorioretinal lesions The model is being improved to account for blood-flow cooling effects during longterm hyperthermia Data were collected using this long-term mode on Greene’s melanoma implanted in the rabbit choroid, and these data indicate that tumor regression can be achieved at levels that are consistent with damage integral predictions

Journal ArticleDOI
TL;DR: Des images d'echographie B obtenues a partir de different positions angulaires du plan de section transversale sont retenues for la reconstruction d'image en mode de reflexion as discussed by the authors.
Abstract: Des images d'echographie B obtenues a partir de differentes positions angulaires du plan de section transversale sont retenues pour la reconstruction d'image en mode de reflexion

Journal ArticleDOI
TL;DR: In this paper, the propagation characteristics of the layered structure consisting of anSiO2 film on 128"rotated Y-cut X-propagating LiNb03 structure are investigated for surface acoustic waves (SAWS).
Abstract: The propagation characteristics of the layered structure consistingof anSiO2 film on 128"rotated Y-cut X-propagating LiNb03 structure are investigated for surface acoustic waves (SAWS). The SiOz fiis are fabricated by radio-frequency (RF) magnetron sputtering techniques. Rayleigh-type waves are excited and detected by conven- tional inter digital transducers (IDT's) fabricated on the LiNbO3 crystal plates. Excellent results have been obtained not only for the tempera- ture characteristics with a temperature coefficient of delay (TCD, of about 0 ppm/"C but also for the frequency characteristics with a very small spurious response. Also, the attenuation constant is found to be very small and the layered structure exhibits a high value of electro- mechanical coupling coefficient (K') of about 0.08. The spurious re- sponse characteristics of the layered structure have been investigated theoretically by analyzing the generation of acoustic waves using IDT's and the spurious response is found to be small.

Journal ArticleDOI
K. Kawashima1
TL;DR: In this paper, the authors calculate quantitatif and mesure des impulsions ultrasonores a la fois longitudinales and transversales dans un echantillon d'aluminium produits par une force verticale superficielle.
Abstract: Calcul quantitatif et mesure des impulsions ultrasonores a la fois longitudinales et transversales dans un echantillon d'aluminium produits par une force verticale superficielle. La force electromagnetique superficielle produite sur la surface metallique par un courant impulsionnel s'ecoulant dans une bobine plate a ete utilisee comme source sonore etalon quantitative et cette force a ete calculee en utilisant le courant impulsionnel observe et les dimensions de la bobine

Journal ArticleDOI
TL;DR: An ultrasonic phased array applicator for hyperthermia provides electronic steering of the sound beam rather than mechanical movement of the transducer assembly as mentioned in this paper, and the effects of various design parameters, including individual array height and length, are discussed.
Abstract: An ultrasonic phased array applicator for hyperthermia provides electronic steering of the sound beam rather than mechanical movement of the transducer assembly. An applicator consisting of a stack of linear phased arrays is examined. The effects of various design parameters, including individual array height and length, are discussed. work was supported in part by URI Therm-X, Inc., and in part by the National Institute of Health under NIH Training Gr-ant CA 09067. and Computer Engineering Department, University of Illinois, 1406 West Green St., Urbana, IL 61801. Manuscript received December 20,1983; revised July 17,1984. This The authors are with the Bioacoustics Research Laboratory, Electrical

Journal ArticleDOI
TL;DR: Les systemes d'imagerie ultrasonore dependent des transducteurs de l'electronique de controle pour la generation des impulsions d'irradiation pour the detection des echos reflechis and the conversion des donnees en forme numerique.
Abstract: Les systemes d'imagerie ultrasonore dependent des transducteurs de l'electronique de controle pour la generation des impulsions d'irradiation pour la detection des echos reflechis et la conversion des donnees en forme numerique

Journal ArticleDOI
TL;DR: In this paper, a real-time tomographic system for imaging the nonlinear parameter B/A of biological objects is proposed, where an impulsive, relatively high-power pumping wave is applied from a direction perpendiculax to the continuous low-intensity high-frequency probing wave so that the phase of the probing wave is modulated instantly by the product of the parameters of the object and pressure of the pumping wave.
Abstract: Absrruci-In this paper a novel real-time tomographic system for imaging the nonlinear parameter B/A of biological objects is proposed. This parameter is related closely to the detailed structure and property of tissues, and may well provide a new dimensional and powerful tool for ultrasonic tissue characterization. In this system an impulsive, relatively high-power pumping wave is applied from a direction perpendiculax to the continuous low-intensity high-frequency probing wave so that the phase of the probing wave is modulated instantly by the product of the parameter B/A of the object and pressure of the pumping wave. Then the resulting spatially-modulated probing wave is detected and demodulated to derive the distribution of B/A along the probing beam. An inverse-filtering operation is employed to compensate for the spread of the pumping wave. The processes are repeated by shifting the position of the probing beam and a two-dimensional image is obtained. A prototype of the imaging system is constructed and images related to the nonlinear parameter of phantoms and human tissues are obtained. The usefulness of this method is shown in these experimental results.

Journal ArticleDOI
TL;DR: In this paper, the authors simulated the temperature distributions produced in deep-seated tumors by focused, scanned ultrasound and compared different power depositions using the Rayleigh-Sommerfeld diffraction integral and then used as inputs to calculate tissue temperatures.
Abstract: Ahstmcr-The temperature distributions produced in deep-seated tumors by focused, scanned ultrasound are simulated. Power depositions are calculated using the Rayleigh-Sommerfeld diffraction integral and are then used as inputs to the two-dimensional bio-heat transfer equation to calculate tissue temperatures. The effects of normal tissue and tumor blood perfusions, tumor location and size, transducer scanning pattern, and transducer characteristics (frequency and f-number) are studied parametrically. The results are presented in terns of the range of applied powers that give acceptable heatings for each situation studied. Low frequency (0.5 MHz), small f-number (0.8) transducers are shown to produce acceptable heatings for a range of scanning patterns and blood perfusions.

Journal ArticleDOI
TL;DR: Absrruct-High-intensity ultrasonic irradiation of the subdermally implanted Yoshida sarcoma was performed to demonstrate that a dramatic reduction in tumor growth can be affected by such therapy.
Abstract: Absrruct-High-intensity ultrasonic irradiation of the subdermally implanted Yoshida sarcoma was performed. Tumor placement was such that the lesion could be pulled away from the trunk section for complete and convenient irradiation. A focused ultrasonic irradiating system, consisting of a 5.5cm diameter 4-MHz quartz transducer driven at resonance, was employed to provide a sound beam small enough in extent to effectively irradiate the tumor without seriously affecting overlying tissues. The therapeutic treatment involved movement of an intense continuous wave (1600 W/cm2 spatial peak, 4-second duration) sound beam over the extent of the tumor volume in a matrix fashion, since the beam cross section was smaller than the tumor to be irradiated. Of 37 animals treated, about 35 percent presented nonpalpable tumors up to 120 days postirradiation. Among the remaining animals, tumor volume was reduced by about 85 percent over those of shams (significance at p < 0.001). The results demonstrate that a dramatic reduction in tumor growth can be affected by such therapy.

Journal ArticleDOI
TL;DR: In this article, the authors used r-transform techniques to model piezoelectric thickness mode transducer behavior and evaluated the response to a variety of arbitrary input functions in the time domain.
Abstract: The validity of using r-transform techniques to model piezoelectric thickness mode transducer behavior is demonstrated. By modeling the transducer as a recursive digital fiiter, the response to a variety of arbitrary input functions may be evaluated directly in the time domain. This eliminates the need for more conventional trans- formation techniques which are limited in extent or distort the time domain response under some conditions. The technique has been successfully employed to model transducer behavior over a wide range of practical operating conditions and this is verified by the experimen- tal results.

Journal ArticleDOI
TL;DR: In this article, the authors provide a perspective of the estimation of attenuation from pulse-echo signals, and overview the various attenuation estimation techniques proposed to date, as well as an overview of the most popular methods.
Abstract: Invited Paper Abstruct-Attenuation is an important parameter in the description prehensions of the physical and computational foundations of the propagation of an ultrasonic pulse in tissue. Since attenuation of the technioues. has been shown to be influenced by tissue state and pathology it also an important factor in the development of quantitative techniques for the measurement of ultrasonic tissue parameters and/or the display of ultrasonic tissue signatures (ultrasonic tissue characterization). Although attenuation is intrinsically defined in terms of a transmission measurement, it can be estimated from an analysis of the backscattered echo waveform. The development of such estimates is fundamentally a problem for digital signal processing. Recent advances in ultrasound instrumentation and computing technology have made the development of attenuation estimation from backscattering practical, thereby suggesting the feasibility of in vivo measurement of attenuation, and creating a popular and important area for research and development. Here we provide a perspective of the estimation of attenuation from pulse-echo signals, and overview the various attenuation estimation techniques proposed to date.

Journal ArticleDOI
TL;DR: In this article, an ultrasonic corrosion monitor is provided which produces an in situ measurement of the amount of corrosion of a monitoring zone or zones of an elongate probe placed in the corrosive environment.
Abstract: An ultrasonic corrosion monitor is provided which produces an in situ measurement of the amount of corrosion of a monitoring zone or zones of an elongate probe placed in the corrosive environment. A monitoring zone is preferably formed between the end of the probe and the junction of the zone with a lead-in portion of the probe. Ultrasonic pulses are applied to the probe and a determination made of the time interval between pulses reflected from the end of the probe and the junction referred to, both when the probe is uncorroded and while it is corroding. Corresponding electrical signals are produced and a value for the normalized transit time delay derived from these time interval measurements is used to calculate the amount of corrosion.

Journal ArticleDOI
TL;DR: In this paper, the authors describe the application of this algorithm to scanning tomographic acoustic microscopy (STAM) and demonstrate the capability of the algorithm's capability in the field of STAM.
Abstract: been applied. The similarities in the two approaches are discussed. The application of this algorithm to scanning tomographic acoustic microscopy (STAM) is described. Simulation results for the application of this algorithm to STAM are presented to demonstrate the algorithm’s capability.

Journal ArticleDOI
TL;DR: In this paper, a set of engineering coefficients were obtained from least-squares fits of simple functions using as input data the involved computations of the edge-and planar-stress effects in quartz thickness mode plates.
Abstract: Absrrocr-Sets of engineering coefficients have been obtained from least-squares fits of simple functions using as input data the involved computations of the edge- and planar-stress effects in quartz thickness mode plates. The fitting coefficients contain the biasing strain and nonlinear elasticity information, yet are suited for engineering applications. AU three thickness modes with orientations on the upper c-mode zero temperature coefficient locus are treated. New values for the thennoelastic coefficients of quartz are also obtained.

Journal ArticleDOI
TL;DR: In this paper, the generalized backward-projection (GPR) method is proposed for acoustic image reconstruction. But the formulation of the GPR is different from ours in terms of objectives and structures, and it is not applicable to all linear imaging systems.
Abstract: Absmct-Reconstruction algorithms have become a major component in acoustical imaging. Special-purpose methods have been developed and successfully applied to various systems. They are similar in terms of concepts and approaches, but they differ in terms of objectives and structures. This paper introduces the formulation of the generalized backward-projection method which is applicable to all linear imaging systems. Both the analog and discrete forms of the algorithm are pre sented for theoretical analysis and practical computation considerations. The main purpose of the paper is to provide a fundamental structure and to serve as a reference for future development of algorithms in acoustic image reconstruction.

Journal ArticleDOI
TL;DR: The seismic data processing technique known as migration represents a method of first reconstructing this wavefield, and then extracting from this wave field an image of the subsurface structure as mentioned in this paper.
Abstract: Geophysical inversion seeks to determine the structure of the interior of the earth from data obtained at the surface. The entire seismic experiment can be described as a propagating wavefield, and the observed seismic data represent the values of this wavefield measured at the surface of the earth. The seismic data processing technique known as migration represents a method of first reconstructing this wavefield, and then extracting from this wavefield an image of the subsurface structure. More specifically, migration may be described as the process of the depropagation of the surface seismic data backward in time, and the required image is obtained when time is reduced to zero. Because the depropagation process itself requires knowledge of the unknown structure, various types of migration processes have evolved to overcome this difficulty. In the popular methods of constant-velocity migration and stratified-velocity migration, statistical arguments are used as justification, whereas in the method known as depth migration, an iterative improvement approach can be used.

Journal ArticleDOI
TL;DR: In this article, the performance of a conventional pair of surface acoustic wave interdigital transducers (IDT) used to generate bulk acoustic waves is analyzed and closed-form expressions are derived for the important electrical and acoustical delay line characteristics and comparison is made with experimental measurements.
Abstract: Absrruct-The performance of a conventional pair of surface acoustic wave interdigital transducers (IDT’s) used to generate bulk acoustic waves is analyzed. An IDT located on the upper surface of a thick, rotated Ycut quartz crystal acts as the acoustic equivalent of an array antenna, launchingacollimated beam into the crystal bulk. The beam is reflected off the crystal bottom and redirected towards the upper crystal surface where it is intercepted by a second receiving IDT. Closed-form expressions are derived for the important electrical and acoustical delay line characteristics and comparison is made with experimental measurements. The analyzed characteristics of the reflected bulk wave (RBW) delay line are significantly different from either the SAW or SSBWand include a) a frequency bandwidth directly proportional to transducer length, b) a center frequency determined not by finger-to-finger spacing but rather by the ratio of transducer separation to crystal thickness, c) a nonresonant radiation resistance, d) the capability to synthesize filter designs in which the frequency response is proportional to the correlation of the individual transducer finger weightings, and e) the capability to modify temperature stability by change of transducer separation and crystal thickness. ULK ACOUSTIC wave radiation generated by interdigital B transducers has historically been considered as spurious, often degrading or interfering with the performance of devices based upon surface acoustic wave (SAW) excitation. Within the last several years, however, there has been increased interest in utilizing the bulk waves generated by IDT’s for practical microwave applications. Such surface-generated bulk waves make use of the IDT as an acoustic equivalent of a phasedarray antenna, with the electrode fingers constituting the array elements. The phasing between these elements is controlled by the applied signal frequency thereby allowing the direction of the acoustic beam radiated into the bulk to be scanned.

Journal ArticleDOI
TL;DR: In this paper, the effects of acoustic waves on the terminal characteristics of electron devices on piezoelectric semiconductors are considered. And the authors propose a new model for the acousto-electric interaction in electron devices such as diodes or FET's located in the acoustic beam path.
Abstract: The effects of acoustic waves on the terminal characteristics of electron devices on piezoelectric semiconductors are considered. The piezoelectric displacement charge is regarded as a time- and space-vary ing perturbation of the doping density of the semiconductor. Incorpora- tion of this doping perturbation into the usual acoustically quiescent device model yields the acoustically perturbed characteristics. In par- tieular, the interaction of a surface acoustic wave with a fieldeffect transistor on GaAs is considered. Good agreement with experimental data is demonstrated. etal. (7) attempted to demonstrate a memory correlator using diodes in the SAW beam path on GaAs. Melloch and Wagers (SI circumvented the cause of failure of these devices by sit- uating the diodes outside the beam path, coupling the diodes to the SAW with fingersover the beam path, and have achieved encouraging results. This author has proposed a memory cor- relator structure, recently discussed by colleagues (7) as the design most appropriate for wide-band applications, in which reference waveform storage and subsequent correlation with the input signal are performed by FET's in a SAW beam path. In the present contribution, a new model for the acousto- electric interaction in electron devices such as diodes or FET's located in the acoustic beam path is developed. In this model, the primary effect of the acoustic wave is to create a piezo- electric displacement charge which is viewed as a change in effective doping density in the semiconductor. In addition, piezoresistive effects produce changes in doping density and in carrier mobility. The former piezoresistive effect is readily added to the piezoelectric displacement charge but is shown to

Journal ArticleDOI
TL;DR: In this article, filtres a ondes acoustiques de surface utilisant des transducteurs interdigitaux avec des doigts incurves have been interviewed.
Abstract: Reponse de filtres a ondes acoustiques de surface utilisant des transducteurs interdigitaux avec des doigts incurves