Mathematical simulation of pressure pulse propagation in biological tissues.

abstract：:An autoregressive (AR) spectral estimation method was considered for the purpose of estimating scatterer size images. The variance and bias of the resulting estimates were compared with those using classical FFT periodograms for a range of input signal-to-noise ratios and echo-signal durations corresponding to various...

journal_title：Ultrasonic imaging

authors： Chaturvedi P,Insana MF

更新日期：1996-01-01 00:00:00

abstract：:To perform computer-aided diagnosis of the thyroid nodules on ultrasound images, the location and boundary of nodules should be clearly defined. However, the identification of thyroid nodule boundary is a difficult issue due to the biological characteristics of the nodules, the physics and quality of ultrasound imagin...

journal_title：Ultrasonic imaging

authors： Chiu LY,Chen A

更新日期：2019-07-01 00:00:00

abstract：:The aim of this study was to identify independent risk factors for thyroid cancer, establish an ultrasonographic multimodality diagnostic model for thyroid nodules, and explore the diagnostic value of the model. From November 2011 to February 2015, 307 patients with a total of 367 thyroid nodules underwent conventiona...

journal_title：Ultrasonic imaging

authors： Zhao RN,Zhang B,Jiang YX,Yang X,Lai XJ,Zhu SL,Zhang XY

更新日期：2019-03-01 00:00:00

abstract：:Coherent speckle is a source of image noise in ultrasonic B-mode imaging. The use of multiple imaging frequencies has been suggested as a technique for speckle contrast reduction. This technique involves the averaging of images whose speckle patterns have been modified by a change in the spectrum of the transmitted or...

journal_title：Ultrasonic imaging

authors： Trahey GE,Allison JW,Smith SW,von Ramm OT

更新日期：1986-07-01 00:00:00

abstract：:The theory of diffraction tomography for two-dimensional objects within the Born approximation is presented for cases where the scattered field is measured over arbitrarily shaped boundaries surrounding the object. Reconstruction algorithms are presented for both plane wave (parallel beam) and cylindrical wave (fan be...

journal_title：Ultrasonic imaging

authors： Devaney AJ,Beylkin G

更新日期：1984-04-01 00:00:00

abstract：:A Fourier transform (FT)-based technique for forming parallel receive beams has been previously employed to increase the imaging frame rate in ultrasonic imaging. However, the image quality in FT-based parallel reconstruction is degraded because differences in range focusing delays are ignored and a wide transmit beam...

journal_title：Ultrasonic imaging

authors： Li ML,Li PC

更新日期：2003-04-01 00:00:00

abstract：:An algorithm for deconvolution of medical ultrasound images is presented. The procedure involves estimation of the basic one-dimensional ultrasound pulse, determining the ratio of the covariance of the noise to the covariance of the reflection signal, and finally deconvolution of the rf signal from the transducer. Usi...

journal_title：Ultrasonic imaging

authors： Jensen JA,Mathorne J,Gravesen T,Stage B

更新日期：1993-04-01 00:00:00

abstract：:Hall effect imaging is an ultrasound-based method of mapping spatial variations in the dielectric constants of an acoustically-uniform sample. This paper presents three-dimensional Hall effect images of phantoms obtained by scanning a single transducer across a two-dimensional grid, effectively simulating two-dimensio...

journal_title：Ultrasonic imaging

authors： Wen H

更新日期：1999-07-01 00:00:00

abstract：:In this paper, quantitative tomographic reconstructions of biological tissue are presented. First, the experimental setup and a hybrid filtered backpropagation (FBP) technique are briefly described. Using this technique, which includes exact backpropagation of data prior to reconstruction by means of the classical FBP...

journal_title：Ultrasonic imaging

authors： Sponheim N,Gelius LJ,Johansen I,Stamnes JJ

更新日期：1994-01-01 00:00:00

abstract：:A method has been developed for mapping density and ultrasonic speed in 1 mm thick slices of soft tissue with a resolution of about 1 mm. Tests using phantom sections have verified the accuracy and resolution of the ultrasonic speed maps. The method has been applied to breast tissues of three patients including tumors...

journal_title：Ultrasonic imaging

authors： Yang JN,Murphy AD,Madsen EL,Zagzebski JA,Gilchrist KW,Frank GR,Macdonald MC,Millard CA,Faraggi A,Jaramillo CA

更新日期：1991-01-01 00:00:00

abstract：:Sidelobe contribution from off-axis targets degrades image quality in a coherent array imaging system. In ultrasound imaging, focusing errors resulting from sound-velocity inhomogeneities in human tissue--also known as phase aberrations reduce the coherence of the received signals and elevate the sidelobe level. This ...

journal_title：Ultrasonic imaging

authors： Li ML,Huang SW,Ustüner K,Li PC

更新日期：2005-04-01 00:00:00

abstract：:Optimal transmit phasing has been proposed to increase contrast-to-tissue ratio (CTR) by relatively phasing the tissue and leakage harmonic components to cancel each other out for tissue-background suppression in harmonic imaging. Since most clinical systems are only equipped with a bipolar square-wave pulser, effecti...

journal_title：Ultrasonic imaging

authors： Shen CC,Yang YC,Chen WS

更新日期：2010-01-01 00:00:00

abstract：:A new online signal processing technique is described to reduce speckle noise in ultrasound images. In the imaging system, a focused piston transducer is divided into thirty-two sectors. In the receive mode, parallel signal processing arranges the sectors into eight maltese crosses. The rf signals of the perpendicular...

journal_title：Ultrasonic imaging

authors： Smith SW,von Ramm OT

更新日期：1988-07-01 00:00:00

abstract：:For a class of scattering objects the mean separation between the scatterers is determined. Over a range of frequencies, ultrasonic back-scattered pressure signals are recorded. It is suggested to derive the mean spacing of an unknown scattering object by employing Fourier analysis and comparing the signal with signal...

journal_title：Ultrasonic imaging

authors： Koch I

更新日期：1983-10-01 00:00:00

abstract：:Portable ultrasound is recently emerging as a new medical imaging modality featuring high portability, easy connectivity, and real-time on-site diagnostic ability. However, it does not yet provide ultrasound elastography function that enables the diagnosis of malignant lesions using elastic properties. This is mainly ...

journal_title：Ultrasonic imaging

authors： Shin B,Jeon S,Ryu J,Kwon HJ

更新日期：2017-11-01 00:00:00

abstract：:In medical ultrasound imaging, two-dimensional (2-D) array transducers are desirable to implement dynamic focusing and phase aberration correction in two dimensions as well as volumetric imaging. Unfortunately, the small size of a 2-D array element results in a small clamped capacitance and a large electrical impedanc...

journal_title：Ultrasonic imaging

authors： Goldberg RL,Smith SW

更新日期：1995-04-01 00:00:00

abstract：:Phased-array images have been obtained in vivo with a steered copolymer array operating at 2.5 MHz. The array was fabricated using 28 microns copolymer film, lambda/4 resonant at 21 MHz, which was bonded to a glass ceramic backing with a thin film bond. The 32 array elements were created by laser ablation of the conti...

journal_title：Ultrasonic imaging

authors： Goldberg RL,Smith SW,Brown LF

更新日期：1992-07-01 00:00:00

abstract：:Volume reconstruction method plays an important role in improving reconstructed volumetric image quality for freehand three-dimensional (3D) ultrasound imaging. By utilizing the capability of programmable graphics processing unit (GPU), we can achieve a real-time incremental volume reconstruction at a speed of 25-50 f...

journal_title：Ultrasonic imaging

authors： Wen T,Li L,Zhu Q,Qin W,Gu J,Yang F,Xie Y

更新日期：2017-07-01 00:00:00

abstract：:In this work, we study linear array beamforming for vibro-acoustography systems. The goal of this research is to assess the feasibility of vibro-acoustography imaging systems based on linear arrays for clinical applications. The vibro-acoustography transducer is designed with two arrays driven by two continuous-wave o...

journal_title：Ultrasonic imaging

authors： Silva GT,Greenleaf JF,Fatemi M

更新日期：2004-01-01 00:00:00

abstract：:The methods of statistical pattern recognition have been applied to the problem of in vivo ultrasonic characterization of breast disease in humans. Backscattered A-mode signals obtained from a commercial pulse imaging system were used to generate a large set of potentially useful features. Using statistical tests, a s...

journal_title：Ultrasonic imaging

authors： Finette S,Bleier AR,Swindell W,Haber K

更新日期：1983-01-01 00:00:00

abstract：:Our group has proposed the concept of subharmonic aided pressure estimation (SHAPE) utilizing microbubble-based ultrasound contrast agent signals for the noninvasive estimation of hydrostatic blood pressures. An experimental system for in vitro SHAPE was constructed based on two single-element transducers assembled co...

journal_title：Ultrasonic imaging

authors： Halldorsdottir VG,Dave JK,Leodore LM,Eisenbrey JR,Park S,Hall AL,Thomenius K,Forsberg F

更新日期：2011-07-01 00:00:00

abstract：:The liver has been hypothesized to have a unique arrangement of microvasculature that presents as an arrangement of quasiperiodic scatterers to an interrogating ultrasound pulse. The mean scatterer spacing (MSS) of these quasiperiodic scatterers has been proposed as a useful quantitative ultrasound biomarker for chara...

journal_title：Ultrasonic imaging

authors： Rubert N,Varghese T

更新日期：2014-04-01 00:00:00

abstract：:Previously reported data on the temperature dependence of propagation speed in tissues generally span only temperature ranges up to 60 degrees C. However, with the emerging use of thermal ablative therapies, information on variation in this parameter over higher temperature ranges is needed. Measurements of the ultras...

journal_title：Ultrasonic imaging

authors： Techavipoo U,Varghese T,Zagzebski JA,Stiles T,Frank G

更新日期：2002-10-01 00:00:00

abstract：:Statistical pattern recognition procedures allow a quantitative description of ultrasound-B-scan image texture. According to well-established animal models, different types of fatty liver disease were induced in female Wistar rats. For the correlation of the computerized ultrasound image with its underlying histology ...

journal_title：Ultrasonic imaging

authors： Layer G,Zuna I,Lorenz A,Zerban H,Haberkorn U,Bannasch P,van Kaick G,Räth U

更新日期：1990-07-01 00:00:00

abstract：:In pulsed Doppler ultrasound systems, the ultrasound radiofrequency (RF) signals received can be employed to estimate noninvasively the time-dependent blood velocity distribution within and artery. The RF signals are composed of signals originating from clutter (e.g., vessel walls) and scatterers (e.g., red blood cell...

journal_title：Ultrasonic imaging

authors： Ledoux LA,Brands PJ,Hoeks AP

更新日期：1997-01-01 00:00:00

abstract：:Acoustic form factors have been used to model the frequency dependence of acoustic scattering in phantoms and tissues. This work demonstrates that a broad range of scatterer sizes, individually well represented by Faran theory or a Gaussian form factor, is not accurately described by a single effective scatterer from ...

journal_title：Ultrasonic imaging

authors： Nordberg EP,Hall TJ

更新日期：2015-01-01 00:00:00

abstract：:The potential of using the phase derivative (PD) of the radio-frequency echograms for producing 2-dimensional grey scale images was further investigated. The PD images were produced by five different algorithms, which according to the results described in the companion paper yield PD images dominated by the amplitude ...

journal_title：Ultrasonic imaging

authors： Oosterveld BJ,Romijn RL,Thijssen JM

更新日期：1989-07-01 00:00:00

abstract：:Tissues exhibiting quasi-periodic structures can be modeled as a collection of diffuse scatterers and coherent scatterers. The mean scatterer spacing (MSS) of coherent and quasi-periodic components is directly related to tissue microstructure and has become an important quantitative ultrasound (QUS) parameter in the c...

journal_title：Ultrasonic imaging

authors： Zhou Z,Wu W,Wu S,Jia K,Tsui PH

更新日期：2017-09-01 00:00:00

abstract：:A narrow-band ultrasonic shear-wave imaging technique for estimating phase speed was applied to fresh and thermally damaged porcine liver in vitro. Two constitutive models were applied to the measurements to represent rheological behavior of the tissue and estimate the complex shear modulus at frequencies between 50 a...

journal_title：Ultrasonic imaging

authors： Orescanin M,Qayyum MA,Toohey KS,Insana MF

更新日期：2010-10-01 00:00:00

abstract：:It may be possible to diagnose and monitor scarring, inflammation and edema in transplant kidney using reconstructive ultrasound elasticity imaging. Kidney elasticity is expected to change dramatically with scar, and to a lesser degree, with acute inflammation and edema. The hypothesis that changes in kidney elasticit...

journal_title：Ultrasonic imaging

authors： Emelianov SY,Lubinski MA,Skovoroda AR,Erkamp RQ,Leavey SF,Wiggins RC,O'Donnell M

更新日期：2000-07-01 00:00:00