Diffraction tomography using arbitrary transmitter and receiver surfaces.

abstract：:Peripheral artery disease is often asymptomatic, and various imaging and nonimaging techniques have been used for assessment and monitoring treatments. This study is designed to demonstrate the ability of photoacoustic imaging to noninvasively determine changes in tissue oxygenation that occur in mice's hind limb skel...

journal_title：Ultrasonic imaging

authors： Kirkham BM,Schultz SM,Ashi K,Sehgal CM

更新日期：2019-09-01 00:00:00

abstract：:Experimental work using a quantitative C-scan technique to measure in situ enhancement of hepatic backscatter resulting from the administration of gelatin microspheres to dogs is reported. We have found that reproducible enhancement of hepatic backscatter on the order of 2 dB followed the peripheral administration of ...

journal_title：Ultrasonic imaging

authors： Ophir J,Gobuty A,Maklad N,Tyler T,Jaeger P,McWhirt R

更新日期：1985-10-01 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：: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：:Modern ultrasound Doppler systems are facing the problem of processing increasingly shorter data sets. Spectral analysis of the strongly nonstationary Doppler signal needs to shorten the analysis window while maintaining a low variance and high resolution spectrum. Color flow imaging requires estimation of the Doppler...

journal_title：Ultrasonic imaging

authors： Herment A,Giovannelli JF

更新日期：1995-01-01 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：: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 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：: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：: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：: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 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：: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：: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：:Acoustic Radiation Force Impulse (ARFI) imaging is a method for characterizing local variations in tissue mechanical properties. In this method, a single ultrasonic transducer array is used to both apply temporally short localized radiation forces within tissue and to track the resulting displacements through time. In...

journal_title：Ultrasonic imaging

authors： Nightingale K,Bentley R,Trahey G

更新日期：2002-07-01 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 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 aim of this study was to assess whether acoustic structure quantification (ASQ) can differentiate normal from pathological thyroid parenchyma in patients with diffuse autoimmune thyroid disease (AITD). We evaluated 83 subjects (72 [87%] women and 11 [13%] men) aged 19 to 94 years with a mean age of 53 years. We pe...

journal_title：Ultrasonic imaging

authors： Zandieh S,Bernt R,Zwerina J,Haller J,Knoll P,Seyeddain O,Mirzaei S

更新日期：2016-03-01 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：:An adaptive scan sequence is proposed for real-time ultrasound three-dimensional (3-D) imaging. Generally, the refresh rate of 3-D imaging is limited by the view window, resolution and sound speed in the human body. If the object is transformed or moved during the data set acquisition, the 3-D image will be distorted....

journal_title：Ultrasonic imaging

authors： Hashimoto H,Takeuchi Y

更新日期：2003-10-01 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：: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：: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：:Behavior and limitations of the sinc basis method have been discovered during simulation studies. An iterative row-action method (ART) is compared with a full-matrix, least-squares solution (QR decomposition) and the problem of multiple solutions is discussed. Knowledge of the spatial distribution of scattered field e...

journal_title：Ultrasonic imaging

authors： Cavicchi TJ,O'Brien WD Jr

更新日期：1989-01-01 00:00:00

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：: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：: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：: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：: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：: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