Intrinsic spectral broadening (ISB) in ultrasound Doppler as a combination of transit time and local geometrical broadening

Guidi, Gabriele; Licciardello, Cinzia; Falteri, S.

doi:10.1016/s0301-5629(00)00218-0

Cited by 44 publications

(24 citation statements)

References 21 publications

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“…Similarly to other Doppler-based flow measurements, 17 the PAD spectrum around f 0 + f PAD is broadened due to several mechanisms. These mechanisms include the finite dimensions and spatial inhomogeneities of the excitation beam which, respectively, truncates and modulates the response of each particle, the finite size of the ultrasound detector, which leads to a distribution of angles θ [and hence, according to Eq.…”

Section: Methods and Experimental Setupmentioning

confidence: 78%

Simultaneous spatial and spectral mapping of flow using photoacoustic Doppler measurement

2010

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Abstract. We demonstrate the use of tone-burst excitation and timegated spectral analysis for photoacoustic Doppler mapping of flow in an unperturbed vessel phantom and in a vessel with a spatially varying lumen. The method, which mimics pulsed Doppler ultrasound, enables simultaneous measurement of axial position and flow as well as complete characterization of the Doppler spectrum over a wide range of mean velocities (3.5 to 200 mm/s). To generate the required optical excitation, a continuous cw laser source followed by an external electro-optic modulator is used. Stenoses at various levels are emulated in a C-flex tube with a flowing suspension of micrometerscale carbon particles. Two-dimensional maps of spectral content versus axial position at different points along the vessel and for various levels of perturbations demonstrate the potential use of the method for characterization of flow irregularities. C 2010 Society of Photo-Optical Instrumentation Engineers.

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Section: Methods and Experimental Setupmentioning

confidence: 78%

Simultaneous spatial and spectral mapping of flow using photoacoustic Doppler measurement

2010

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“…Such assumption is valid near the focal region of the ultrasound beam, and thus our simulations simply examined flow lines near the beam focus. For flow lines away from the beam focus, Ata and Fish [26] and Guidi et al [27] have shown that frequency modulation also may arise in the Doppler signal owing to the extended effective beam width, which in turn gives rise to deviations in the beam-flow angle as the scatterer traverses through the sample volume. Under such circumstances, the generalized amplitude modulation signal model would need further modifications.…”

Section: Discussionmentioning

confidence: 99%

Transit-time broadening in pulsed Doppler ultrasound: a generalized amplitude modulation model

Steinman

Cobbold

2006

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

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In Doppler ultrasound, transit-time broadening arises from the finite scatterer transit time through the sample volume. As a unifying description of this broadening mechanism, a generalized amplitude modulation signal model was developed to collectively account for the transittime effects of the ultrasound beam geometry and the range gate characteristics. Simulations based on a pulsed lineararray system also were performed to study the broadening extent for different scatterer flow lines. With our signal model and simulation results, some generalized insights were obtained on the characteristics of transit-time broadening. First, as consistent with previous findings, we found that, for scatterers passing though the center of the sample volume, the broadening extent mainly depends on beamforming characteristics at higher beam-flow angles, but it is more dependent on range gate parameters at smaller angles. Second, for the central flow line, a transition angle exists in which a significant change occurs in the governing parameters of transit-time broadening. Third, for the general case in which scatterers undertake an off-central path through the sample volume, the broadening extent depends on both the beam geometry and the range gate. Bandwidth skewing and further spectral broadening also can be seen for these off-central flow lines.

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“…The error increase can be explained by noting that the amplitude modulation resulting from the finite scatterer transit time through the SV concomitantly decreases as the beam-flow angle increases and, thus, the extent of intrinsic spectral broadening is more prominent at larger beam-flow angles (Newhouse et al 1987). Spectral broadening may also arise in the form of frequency modulation caused by deviations in the beam-flow angle as scatterers move through the SV (Ata and Fish 1991;Guidi et al 2000). Hoskins et al (1999) showed that these changes in the subtended angle can be significant for a phased linear array and can, therefore, contribute to the velocity estimation error.…”

Section: Beam-flow Angle-dependencementioning

confidence: 99%

Effects of beam steering in pulsed-wave ultrasound velocity estimation

Steinman

Johnston

et al. 2005

Ultrasound in Medicine & Biology

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Intrinsic spectral broadening (ISB) in ultrasound Doppler as a combination of transit time and local geometrical broadening

Cited by 44 publications

References 21 publications

Simultaneous spatial and spectral mapping of flow using photoacoustic Doppler measurement

Simultaneous spatial and spectral mapping of flow using photoacoustic Doppler measurement

Transit-time broadening in pulsed Doppler ultrasound: a generalized amplitude modulation model

Effects of beam steering in pulsed-wave ultrasound velocity estimation

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