In vivo imaging using a copolymer phased array.

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：: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：: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：:Two-dimensional echocardiography (2-D echo) imaging is a more attractive clinical tool than other modalities that either involve radiation exposure or are too slow to image heart motion in real-time. Computer-aided analysis of left ventricular(LV) wall motion provides quantitative parameters for diagnosis. This study ...

journal_title：Ultrasonic imaging

authors： Chen T,Chen TP,Tsai LM

更新日期：1997-04-01 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

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：: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：: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：:Attenuation measurements of various tissue mimicking phantoms and three different groups of patients were obtained using a modified commercial sector scanner. Estimates of attenuation were made using the spectral shift method with mean frequencies at different depths of a region of interest being obtained by both zero...

journal_title：Ultrasonic imaging

authors： Garra BS,Shawker TH,Nassi M,Russell MA

更新日期：1984-10-01 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：:Muscle fatigue often occurs over a long period of exercise, and it can increase the risk of muscle injury. Evaluating the state of muscle fatigue can avoid unnecessary overtraining and injury of the muscle. Ultrasound imaging can non-invasively visualize muscle tissue in real-time. Image entropy is commonly used to ch...

journal_title：Ultrasonic imaging

authors： Li P,Yang X,Yin G,Guo J

更新日期：2020-11-01 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：:This study shows that the amplitude information of ultrasound echoes is carried mainly by the envelope peaks (EPs). It is first shown that the EPs in an A-line represent the maximum number of independent amplitude data. It is then demonstrated that the entire envelope could be approximately reconstructed from the EPs....

journal_title：Ultrasonic imaging

authors： He P

更新日期：1988-10-01 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

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：: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 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：:This paper describes a method for overcoming motion artifacts in synthetic aperture imaging. The method is based on a computer simulation study on the influence of target motion on synthetic aperture techniques. A region-based motion compensation approach is used in which only the axial motion is estimated and compens...

journal_title：Ultrasonic imaging

authors： Kim KS,Hwang JS,Jeong JS,Song TK

更新日期：2002-04-01 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：: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：: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：: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：: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 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：: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：: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：:Computer texture analysis methods use texture features that are traditionally chosen from a large set of fixed features known in literature. These fixed features are often not specifically designed to the problem at hand, and as a result they may have low discriminative power, and/or may be correlated. Increasing the ...

journal_title：Ultrasonic imaging

authors： Huisman HJ,Thijssen JM

更新日期：1998-04-01 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：: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：: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