A new system for in vivo assessment of the degree of nonlinear generation using the second harmonic component in echo signals

Fujii, Yasutomo; Taniguchi, Nobuyuki; Akiyama, Iwaki; Tsao, Jing-Wen; Itoh, Kouichi

doi:10.1016/j.ultrasmedbio.2004.08.016

Cited by 11 publications

(10 citation statements)

References 15 publications

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“…Both the glass beads and graphite powder were used as acoustic scatterers in the scattering medium, and the materials of the lipid emulsions were used to produce an acoustic attenuation effect in the phantoms62. Three types of phantoms were constructed, namely Type-A, Type-B, and Type-C. A tissue-mimicking breast phantom (Model BPB170, Blue Phantom, Redmond, WA, USA) was used as a Type-D phantom to provide a simulated mass.…”

Section: Methodsmentioning

confidence: 99%

Small-window parametric imaging based on information entropy for ultrasound tissue characterization

Tsui

Chen

Kuo

et al. 2017

Sci Rep

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Constructing ultrasound statistical parametric images by using a sliding window is a widely adopted strategy for characterizing tissues. Deficiency in spatial resolution, the appearance of boundary artifacts, and the prerequisite data distribution limit the practicability of statistical parametric imaging. In this study, small-window entropy parametric imaging was proposed to overcome the above problems. Simulations and measurements of phantoms were executed to acquire backscattered radiofrequency (RF) signals, which were processed to explore the feasibility of small-window entropy imaging in detecting scatterer properties. To validate the ability of entropy imaging in tissue characterization, measurements of benign and malignant breast tumors were conducted (n = 63) to compare performances of conventional statistical parametric (based on Nakagami distribution) and entropy imaging by the receiver operating characteristic (ROC) curve analysis. The simulation and phantom results revealed that entropy images constructed using a small sliding window (side length = 1 pulse length) adequately describe changes in scatterer properties. The area under the ROC for using small-window entropy imaging to classify tumors was 0.89, which was higher than 0.79 obtained using statistical parametric imaging. In particular, boundary artifacts were largely suppressed in the proposed imaging technique. Entropy enables using a small window for implementing ultrasound parametric imaging.

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Section: Methodsmentioning

confidence: 99%

Small-window parametric imaging based on information entropy for ultrasound tissue characterization

Tsui

Chen

Kuo

et al. 2017

Sci Rep

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“…As indicated in Figure7, the C1 and C2 intensities decreased as the lipid concentrations were increased. This is because when the lipid emulsion concentration increases, the phantom increases the attenuation effects to reduce the echo intensity [15]. It should be noted that the IER also decreased as the lipid concentrations were …”

Section: Discussionmentioning

confidence: 94%

“…The lipid concentrations ranged from 0% to 30%, corresponding to the range of attenuation coefficient from 0.684 to 1.108 dB/cm·MHz (the attenuation coefficient of each phantom was calculated using the standard substitution method). A previous study reported that when the lipid concentrations are increased, the brightness of the B-scan decreases accordingly [15]. In total, six independent phantoms were prepared for each lipid concentration (n = 36).…”

Section: Experiments On Lipid Phantomsmentioning

confidence: 99%

Empirical Mode Decomposition of Ultrasound Imagingfor Gain-Independent Measurement on Tissue Echogenicity: A Feasibility Study

Zhou

et al. 2017

Applied Sciences

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Empirical mode decomposition (EMD) is an adaptive method for decomposing a signal into intrinsic mode functions (IMFs).This study explored using EMD of ultrasound imaging for gain-independent measurements on tissue echogenicity. The IMF-based echogenicity ratio (IER) was proposed using the first (C 1 ) and second IMFs (C 2 ) of ultrasound radiofrequency data. Experiments on lipid phantoms were conducted to investigate the practical performance of IER. Phantoms with lipid concentrations 0%-30% (n = 36) were scanned using a clinical ultrasound scanner to acquire the radiofrequency data under different gains (12-33 dB) for EMD and IER calculations. Experiments on a tissue-mimicking phantom were further performed using the same ultrasound system and data acquisition procedure to investigate the effect of ultrasound frequency on the IER at5-8 MHz.Experimental results showed that the IER measured under 33-dB gain decreased from 6.65 ± 0.23 to 3.97 ± 0.10 when the lipid concentrations were increased from 0% to 30%. When 12-dB gain was used, the IER decreased from 6.21 ± 0.29 to 3.39 ± 0.07. However, whenincreasing the frequency, the IER had a mean decreasing rate of −8.67% per MHz, which was lower than those of the C 1 and C 2 intensities.The proposed IER may allow gain-independent measurement on tissue echogenicity.

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“…The physics describing the propagation of a finite amplitude ultrasonic wave also underpins the improvements in image quality associated with the development of harmonic imaging in clinical echocardiography. Therefore, this work contributes to developments that, in the long term, may contribute to future improvements in diagnostic ultrasound, including potential determination of the nonlinear properties of tissue in vivo (Fujii et al, 2004). Results of simulations showing the values for the left side of eqn 3, for isopropanol (0.804 gm/ cm3 mass density, 1220 m/s speed of sound, 11.8 nonlinear B/A parameter, and frequency dependence of attenuation proportional to square of the frequency), with the specified values of attenuation at a fundamental frequency of 7.0 MHz.…”

Section: Discussionmentioning

confidence: 96%

Finite Amplitude Measurements of the Nonlinear Parameter B/A for Liquid Mixtures Spanning a Range Relevant to Tissue Harmonic Mode

Wallace

Lloyd

Holland

et al. 2007

Ultrasound in Medicine & Biology

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The objective of this investigation was to measure the nonlinear parameter B/A using an enhanced finite amplitude distortion technique, based on nonlinear propagation effects analogous to those associated with tissue harmonic imaging. These measurements validate an improved method for measuring the nonlinear parameter B/A, the small-signal speed of sound, and the attenuation coefficient from a single set of ultrasonic measurements. To test the method, measurements were performed on 11 different mixtures of isopropyl alcohol (isopropanol) and water that span the range of concentrations from 0% to 100% isopropanol. Results for B/A ranging from approximately five to 11 were found to be reproducible and in good agreement with previously published values obtained using a thermodynamic method.

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A new system for in vivo assessment of the degree of nonlinear generation using the second harmonic component in echo signals

Cited by 11 publications

References 15 publications

Small-window parametric imaging based on information entropy for ultrasound tissue characterization

Small-window parametric imaging based on information entropy for ultrasound tissue characterization

Empirical Mode Decomposition of Ultrasound Imagingfor Gain-Independent Measurement on Tissue Echogenicity: A Feasibility Study

Finite Amplitude Measurements of the Nonlinear Parameter B/A for Liquid Mixtures Spanning a Range Relevant to Tissue Harmonic Mode

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