In vivo imaging using a copolymer phased array.

abstract：:It is well-documented in literature that benign breast lesions, such as fibroadenomas, are loosely bonded to their surrounding tissue and tend to slip under a small quasi-static compression, whereas malignant lesions being firmly bonded to their surrounding tissue do not slip. Recent developments in quasi-static ultra...

journal_title：Ultrasonic imaging

authors： B L,Chintada BR,Thittai AK

更新日期：2017-05-01 00:00:00

abstract：:The propagation of pressure pulses of arbitrary time form in inhomogeneous attenuating media with characteristics similar to real biological tissues is considered. A mathematical model using the quasi-optical approximation is developed to solve the wave equation. Such a model proves to be convenient for computer reali...

journal_title：Ultrasonic imaging

authors： Adrov VN,Chernomordik VV

更新日期：1993-01-01 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：:This ex vivo study explores the relationship of ultrasonic attenuation and backscatter to dermal microarchitecture by comparing ultrasonic measurements of these parameters (11-27 MHz) to a microscopic analysis of three parameters describing the collagen distribution (mean thickness and spacing of collagen bundles alon...

journal_title：Ultrasonic imaging

authors： Bridal SL,Fournier C,Coron A,Leguerney I,Laugier P

更新日期：2006-01-01 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：:Time reversal of ultrasonic field allows a very efficient approach to focusing pulsed ultrasonic waves through lossless inhomogeneous media. Time reversal mirrors (TRM) are made of large transducer arrays, allowing the incident acoustic field to be sampled, time reversed and re-emitted. Time reversal processing permit...

journal_title：Ultrasonic imaging

authors： Thomas JL,Wu F,Fink M

更新日期：1996-04-01 00:00:00

abstract：:Transesophageal echocardiography (TEE) is an essential diagnostic tool in patients with poor transthoracic echocardiographic windows or when detailed imaging of structures distant from the chest wall is necessary. A real-time 3D TEE probe has been fabricated in our laboratory in order to increase the amount of informa...

journal_title：Ultrasonic imaging

authors： Pua EC,Idriss SF,Wolf PD,Smith SW

更新日期：2004-10-01 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：:When modeling or simulating an ultrasonic pulse-echo system it is necessary to know the transducer waveforms that are the input to the system. In general, accurate transducer modeling is complex and waveform calculation is computationally intensive. Because of this, investigators often assume these waveforms to be sim...

journal_title：Ultrasonic imaging

authors： Barber FE,Goodsitt MM

更新日期：1987-10-01 00:00:00

abstract：:Ultrasonic waveform data from a tissue-mimicking phantom containing low contrast targets was digitized, stored and processed prior to creating and displaying ultrasonic images. Speckle reduction was performed by digital filtering of the waveform data with appropriately spaced and weighted digital filters, prior to bot...

journal_title：Ultrasonic imaging

authors： Gehlbach SM,Sommer FG

更新日期：1987-04-01 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：:Mean frequency estimators as used in pulsed Doppler ultrasound equipment should provide an accurate (quality) and consistent (robustness) estimate over a wide range of signal conditions. In a simplified signal model, the main parameters to consider are the noise level, mean frequency, bandwidth and power of both the D...

journal_title：Ultrasonic imaging

authors： Brands PJ,Hoeks AP

更新日期：1992-10-01 00:00:00

abstract：:Acoustic radiation force impulse (ARFI) Surveillance of Subcutaneous Hemorrhage (ASSH) has been previously demonstrated to differentiate bleeding phenotype and responses to therapy in dogs and humans, but to date, the method has lacked experimental validation. This work explores experimental validation of ASSH in a po...

journal_title：Ultrasonic imaging

authors： Geist RE,DuBois CH,Nichols TC,Caughey MC,Merricks EP,Raymer R,Gallippi CM

更新日期：2016-09-01 00:00:00

abstract：:The potential of using the phase derivative (PD) for echographic imaging was investigated. The PD data were calculated by four methods: zero crossing (ZCS) with squelch addition, analytic signal either with squelch addition (ASS) or with employment of a Wiener kernel (ASW), and unwrapped phase (UWP). The large peaks w...

journal_title：Ultrasonic imaging

authors： Romijn RL,Oosterveld BJ,Thijssen JM

更新日期：1987-07-01 00:00:00

abstract：:The amplitude and frequency contents of a received ultrasound pulse depends on the spatial pressure amplitude distribution of the sound field, as produced by the transducer in the medium, and on the position and orientation of the reflecting surface in this field. Often, the geometry of the reflecting surface and the ...

journal_title：Ultrasonic imaging

authors： Linssen FM,Hoeks AP

更新日期：1990-10-01 00:00:00

abstract：:Most methods for in vivo quantitation of ultrasound attenuation and backscatter are not available clinically because they rely upon acquiring and analyzing radio frequency (rf) echo signals. This paper describes a technique to estimate ultrasound attenuation and backscatter from B-mode image data. The video signal ana...

journal_title：Ultrasonic imaging

authors： Knipp BS,Zagzebski JA,Wilson TA,Dong F,Madsen EL

更新日期：1997-07-01 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：: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：:This paper addresses significant sources of electromagnetic noise in Hall effect imaging. Hall effect imaging employs large electrical pulses for signal generation and high sensitivity ultrasonic probes for signal reception. Coherent noise arises through various coupling mechanisms between the excitation pulse and the...

journal_title：Ultrasonic imaging

authors： Wen H,Bennett E,Wiesler DG

更新日期：1998-07-01 00:00:00

abstract：:Accurate tracking of tissue motion is critically important for several ultrasound elastography methods. In this study, we investigate the feasibility of using three published convolution neural network (CNN) models built for optical flow (hereafter referred to as CNN-based tracking) by the computer vision community fo...

journal_title：Ultrasonic imaging

authors： Peng B,Xian Y,Zhang Q,Jiang J

更新日期：2020-03-01 00:00:00

abstract：:Tracking large deformations in tissue using ultrasound can enable the reconstruction of nonlinear elastic parameters, but poses a challenge to displacement estimation algorithms. Such large deformations have to be broken up into steps, each of which contributes an estimation error to the final accumulated displacement...

journal_title：Ultrasonic imaging

authors： Bayer M,Hall TJ

更新日期：2013-04-01 00:00:00

abstract：:Ultrasonic coda wave analysis techniques localize defects in fields such as seismography and nondestructive testing. In medical ultrasound, these techniques might provide novel mapping of tissue properties in diseases characterized by local fibrosis. In this work, we present an approach for localizing variation in sca...

journal_title：Ultrasonic imaging

authors： Lindsey BD,Collins GC

更新日期：2020-01-01 00:00:00

abstract：:The microbubble contrast agent destruction/replenishment technique has been widely applied to ultrasound-based blood flow estimation. The rate of increase of the time-intensity curve (TIC) due to microbubbles flowing into the region of interest as measured from B-mode images closely reflects the flow velocity. In this...

journal_title：Ultrasonic imaging

authors： Tsui PH,Yeh CK,Chang CC

更新日期：2008-07-01 00:00:00

abstract：:Mathematical techniques are described for analyzing tongue shapes obtained with ultrasound images. The surface of the mid-sagittal section of the tongue was approximated by discrete points. In turn, these points were used to approximate position, slope and curvature of the tongue surface at a fixed time during speech....

journal_title：Ultrasonic imaging

authors： Morrish KA,Stone M,Sonies BC,Kurtz D,Shawker T

更新日期：1984-01-01 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：:Generation of the second harmonic signal was studied for finite amplitude distortion based harmonic imaging. Acoustic field amplitudes along the range axis of a fixed focus transducer were measured using a PVDF needle hydrophone. Results indicated that on-axis amplitudes strongly depended on the f-number at both the f...

journal_title：Ultrasonic imaging

authors： Li PC,Shen CC

更新日期：1999-10-01 00:00:00

abstract：:This paper presents a new beamforming technique, in which ultrasound waves are focused at the display pixels on the Cartesian coordinates, rather than sampling points located on the uniformly-separated scanlines on either the polar or Cartesian coordinates. Consequently, this method does not require a digital scan con...

journal_title：Ultrasonic imaging

authors： Hwang JS,Song TK

更新日期：2001-01-01 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：:An ultrasonic imaging and signal analysis system, combining a 3.5 MHz linear array B-scanner and an array processor, has been realized for a clinical liver tissue classification study. Based on the complete unprocessed rf data set of a real time B-image, local envelope power spectra averaged over interactively defined...

journal_title：Ultrasonic imaging

authors： Lang M,Ermert H,Heuser L

更新日期：1994-04-01 00:00:00

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