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 regions are computed. These spectra are partially corrected for several tissue type independent effects that affect comparability. A library containing the in vivo data of 65 patients with known liver tissue states in three groups (normal, cirrhotic, fat) was built up. An algorithm based on numerical optimization of parametrized spectrum characteristics combined with a k-nearest-neighbors classifier, applied to the library, leads to correct classification rates of 85.8 to 87.5 percent in discriminating pathological from normal tissue states. The method can be used for k-weighted color coded tissue type imaging with acceptable spatial resolution.
journal_name
Ultrason Imagingjournal_title
Ultrasonic imagingauthors
Lang M,Ermert H,Heuser Ldoi
10.1177/016173469401600202subject
Has Abstractpub_date
1994-04-01 00:00:00pages
77-86issue
2eissn
0161-7346issn
1096-0910journal_volume
16pub_type
杂志文章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
pub_type: 杂志文章
doi:10.1177/016173460903100303
更新日期:2009-07-01 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
pub_type: 杂志文章
doi:10.1177/016173460502700205
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
pub_type: 杂志文章
doi:10.1177/016173461003200103
更新日期:2010-01-01 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
pub_type: 杂志文章,评审
doi:10.1177/0161734617692018
更新日期:2017-09-01 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
pub_type: 杂志文章
doi:10.1177/016173468500700402
更新日期:1985-10-01 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
pub_type: 杂志文章
doi:10.1177/016173460803000301
更新日期:2008-07-01 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
pub_type: 杂志文章
doi:10.1177/016173460202400202
更新日期:2002-04-01 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
pub_type: 杂志文章
doi:10.1177/016173460102300101
更新日期:2001-01-01 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
pub_type: 杂志文章,评审
doi:10.1177/016173469601800202
更新日期:1996-04-01 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
pub_type: 杂志文章
doi:10.1177/0161734615589287
更新日期:2016-05-01 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
pub_type: 杂志文章
doi:10.1177/016173469701900204
更新日期:1997-04-01 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
pub_type: 杂志文章
doi:10.1177/016173468400600207
更新日期:1984-04-01 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
pub_type: 杂志文章
doi:10.1177/016173460002200303
更新日期:2000-07-01 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
pub_type: 杂志文章
doi:10.1177/016173468600800301
更新日期:1986-07-01 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
pub_type: 杂志文章
doi:10.1177/0161734613479246
更新日期:2013-04-01 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
pub_type: 杂志文章
doi:10.1177/0161734615617940
更新日期:2016-09-01 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
pub_type: 杂志文章
doi:10.1177/016173468901100301
更新日期:1989-07-01 00:00:00
abstract::Speckle noise is known to be signal-dependent in ultrasound imaging. Hence, separating noise from signal becomes a difficult task. This paper describes a wavelet-based method for reducing speckle noise. We derive from the model of the displayed ultrasound image the optimal wavelet-domain filter in the least mean-squar...
journal_title:Ultrasonic imaging
pub_type: 杂志文章
doi:10.1177/016173460002200201
更新日期:2000-04-01 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
pub_type: 杂志文章
doi:10.1177/016173460202400301
更新日期:2002-07-01 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
pub_type: 杂志文章
doi:10.1177/016173461003200405
更新日期:2010-10-01 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
pub_type: 杂志文章
doi:10.1177/016173469301500106
更新日期:1993-01-01 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
pub_type: 杂志文章
doi:10.1177/0161734615580766
更新日期:2016-03-01 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
pub_type: 杂志文章
doi:10.1177/016173469701900101
更新日期:1997-01-01 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
pub_type: 杂志文章
doi:10.1177/016173461103300301
更新日期:2011-07-01 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
pub_type: 杂志文章
doi:10.1177/016173460803000202
更新日期:2008-04-01 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
pub_type: 杂志文章
doi:10.1177/016173469902100401
更新日期:1999-10-01 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
pub_type: 杂志文章
doi:10.1177/016173469001200405
更新日期:1990-10-01 00:00:00
abstract::A scalable architecture for forming real-time synthetic focus images is described and the design of a 256-channel system using currently-available technology is presented as an example implementation of the architecture. The parallelism of the system scales directly with the number of array elements and the image comp...
journal_title:Ultrasonic imaging
pub_type: 杂志文章
doi:10.1177/016173460302500303
更新日期:2003-07-01 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
pub_type: 杂志文章
doi:10.1177/016173468300500107
更新日期:1983-01-01 00:00:00
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
pub_type: 杂志文章
doi:10.1177/0161734619862287
更新日期:2019-09-01 00:00:00