Quantitative assessment of in vivo backscatter enhancement from gelatin microspheres.

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：: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：:Breast ultrasound (BUS) imaging has become a crucial modality, especially for providing a complementary view when other modalities (i.e., mammography) are not conclusive in the task of assessing lesions. The specificity in cancer detection using BUS imaging is low. These false-positive findings often lead to an increa...

journal_title：Ultrasonic imaging

authors： Pons G,Martí J,Martí R,Ganau S,Noble JA

更新日期：2016-05-01 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：:Conventional ultrasonic B-mode images qualitatively describe tissue structures but are unsuitable for quantitative analyses of scatterer properties. We have recently developed an ultrasonic parametric imaging technique based on the Nakagami statistical distribution that is able to quantify scatterer concentrations. Th...

journal_title：Ultrasonic imaging

authors： Tsui PH,Yeh CK,Chang CC,Chen WS

更新日期：2008-04-01 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：: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：: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：:Regional anesthesia is preferred over general anesthesia for many surgical procedures; however, challenges associated with poor image guidance limit its widespread acceptance as a viable alternative. In B-mode ultrasound images, the current standard for guidance, nerves can be difficult to visualize due to their simil...

journal_title：Ultrasonic imaging

authors： Palmeri ML,Dahl JJ,MacLeod DB,Grant SA,Nightingale KR

更新日期：2009-07-01 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：: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：: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：: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：: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：:Acoustic radiation force (ARF) has become a common excitation mechanism in elasticity imaging. The high acoustic intensities and subsequent generation of harmonics, however, hamper the effectiveness of using conventional radiofrequency (rf) tracking to investigate the dynamics of tissues and catheter-based transducers...

journal_title：Ultrasonic imaging

authors： Bouchard RR,Van Soest G,Trahey GE,Van Der Steen AF

更新日期：2009-01-01 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：: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：: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 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：: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 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：: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：: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：: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：:Many noninvasive ultrasound techniques have been developed to explore mechanical properties of soft tissues. One of these methods, Localized Harmonic Motion Imaging (LHMI), has been proposed to be used for ultrasound surgery monitoring. In LHMI, dynamic ultrasound radiation-force stimulation induces displacements in a...

journal_title：Ultrasonic imaging

authors： Heikkilä J,Hynynen K

更新日期：2006-04-01 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：: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 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：: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：: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