An ultrasound research interface for a clinical system

Ashfaq, Mohammad; Brunke, Shelby; Dahl, Jeremy J.; Ermert, H.; Hansen, Christian; Insana, Michael F.

doi:10.1109/tuffc.2006.109

Cited by 68 publications

(17 citation statements)

References 22 publications

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“…Data was collected using a Siemens 4C1 abdominal probe over a 40° field of view consisting of 118 A-lines. Channel data acquisition was made possible by employing a custom synthetic aperture sequence and the Axius Direct™ Ultrasound Research Interface 27 .…”

Section: Methodsmentioning

confidence: 99%

In Vivo Application of Short-Lag Spatial Coherence and Harmonic Spatial Coherence Imaging in Fetal Ultrasound

et al. 2014

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Fetal scanning is one of the most common applications of ultrasound imaging and serves as a source of vital information about maternal and fetal health. Visualization of clinically relevant structures, however, can be severely compromised in difficult-to-image patients due to poor resolution and the presence of high levels of acoustical noise or clutter. We have developed novel coherence-based beamforming methods called Short-Lag Spatial Coherence (SLSC) imaging and Harmonic Spatial Coherence imaging (HSCI) and applied them to suppress the effects of clutter in fetal imaging. This method is used to create images of the spatial coherence of the backscattered ultrasound as opposed to images of echo magnitude. We present the results of a patient study to assess the benefits of coherence-based beamforming in the context of first trimester fetal exams. Matched fundamental B-mode, SLSC, harmonic B-mode and HSCI images were generated using raw RF data collected on 11 volunteers in the first trimester of pregnancy. The images were compared for qualitative differences in image texture and target conspicuity as well as using quantitative imaging metrics such as SNR, CNR and contrast. SLSC and HSCI showed statistically significant improvements across all imaging metrics compared to B-mode and harmonic B-mode respectively. These improvements were greatest for poor quality B-mode images where contrast of anechoic targets was improved from 15 dB in fundamental B-mode to 27 dB in SLSC and 17 dB in harmonic B-mode to 30 dB in HSCI. CNR improved from 1.4 to 2.5 in the fundamental images and 1.4 to 3.1 in the harmonic case. These results exhibit the potential of coherence-based beamforming to improve image quality and target detectability, especially in high noise environments.

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Section: Methodsmentioning

confidence: 99%

In Vivo Application of Short-Lag Spatial Coherence and Harmonic Spatial Coherence Imaging in Fetal Ultrasound

et al. 2014

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“…The backscattered signal was recorded with a Siemens VF7-3 transducer on a Siemens Antares Ultrasound scanner. The transmit frequency was 4.2 MHz and the Axius Direct Ultrasound Research Interface (URI) was used to acquire the data [18]. The same signal processing method that was used for the simulated data was used to determine the experimental spatial coherence curves.…”

Section: Examplesmentioning

confidence: 99%

Spatial coherence in human tissue: implications for imaging and measurement

Pinton¹,

Trahey²,

Dahl³

2014

IEEE Trans. Ultrason., Ferroelect., Freq. Contr.

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The spatial coherence properties of the signal backscattered by human tissue and measured by an ultrasound transducer array are investigated. Fourier acoustics are used to describe the propagation of ultrasound through a model of tissue that includes reverberation and random scatterering in the imaging plane. The theoretical development describes how the near-field tissue layer, transducer aperture properties, and reflectivity function at the focus reduce the spatial coherence of the imaging wave measured at the transducer surface. Simulations are used to propagate the acoustic field through a histologically characterized sample of the human abdomen and to validate the theoretical predictions. In vivo measurements performed with a diagnostic ultrasound scanner demonstrate that simulations and theory closely match the measured spatial coherence characteristics in the human body across the transducer array’s entire spatial extent. The theoretical framework and simulations are then used to describe the physics of spatial coherence imaging, a type of ultrasound imaging that measures coherence properties instead of echo brightness. The same echo data from an F/2 transducer was used to generate B-mode and short lag spatial coherence images. For an anechoic lesion at the focus the contrast to noise ratio is 1.21 for conventional B-mode imaging and 1.95 for spatial coherence imaging. It is shown that the contrast in spatial coherence imaging depends on the properties of the near-field tissue layer and the backscattering function in the focal plane.

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“…32 Two linear arrays were used: a 9L4 transducer operated at 4MHz, and a 18L6 transducer operated at 10MHz. Figure 1(b) shows a B-mode image of the phantom’s vertical fiber plane acquired with the 18L6 transducer.…”

Section: Methodsmentioning

confidence: 99%

Analysis of Coherent and Diffuse Scattering Using a Reference Phantom

Rosado‐Mendez

Drehfal

Zagzebski

et al. 2016

IEEE Trans. Ultrason., Ferroelect., Freq. Contr.

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The estimation of many spectral-based, Quantitative Ultrasound parameters assumes that backscattered echo signals are from a stationary, incoherent scattering process. The accuracy of these assumptions in real tissue can limit the diagnostic value of these parameters and the physical insight about tissue microstructure they can convey. This work presents an empirical decision test to determine the presence of significant coherent contributions to echo signals and whether they are caused by low scatterer number densities or the presence of specular reflectors or scatterers with periodic spacing. This is achieved by computing parameters from echo signals that quantify stationary or non-stationary features related to coherent scattering, and then comparing their values to thresholds determined from a reference material providing diffuse scattering. The paper first presents a number of parameters with demonstrated sensitivity to coherent scattering and describes criteria to select those with highest sensitivity using simulated and phantom-based echo data. Results showed that the echo amplitude signal-to-noise ratio and the multitaper generalized spectrum were the parameters with highest sensitivity to coherent scattering with stationary and non-stationary features, respectively. These parameters were incorporated into the reference-based decision test, which successfully identified regions in simulated and tissue-mimicking phantoms with different incoherent and coherent scattering conditions. When scatterers with periodic organization were detected, the combination of stationary and non-stationary analysis permitted the estimation of the mean spacing below and above the resolution limit imposed by the pulse size. Preliminary applications of this algorithm to human cervical tissue ex vivo showed correspondence between regions of B-mode images showing bright reflectors, tissue interfaces, and hypoechoic regions with regions classified as specular reflectors and low scatterer number density. These results encourage further application of the algorithm to more structurally complex phantoms and tissue.

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An ultrasound research interface for a clinical system

Cited by 68 publications

References 22 publications

In Vivo Application of Short-Lag Spatial Coherence and Harmonic Spatial Coherence Imaging in Fetal Ultrasound

In Vivo Application of Short-Lag Spatial Coherence and Harmonic Spatial Coherence Imaging in Fetal Ultrasound

Spatial coherence in human tissue: implications for imaging and measurement

Analysis of Coherent and Diffuse Scattering Using a Reference Phantom

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