Clinical evaluation of a new anti-aliasing technique for ultrasound pulsed Doppler analysis

Tortoli, Piero; Valgimigli, Francesco; Guidi, Gabriele; Pignoli, P

doi:10.1016/0301-5629(89)90115-4

Cited by 19 publications

(6 citation statements)

References 14 publications

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“…Furthermore, although the proposed method uses the repeated transmit sequence, it still suffers from aliasing. Investigations on increasing the detectable velocity [26][27][28][29] would be preferable to expand the applicability of the proposed method.…”

Section: Discussionmentioning

confidence: 99%

Measurement of flow velocity vectors in carotid artery using plane wave imaging with repeated transmit sequence

et al. 2021

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Purpose Doppler-based methods are widely used for blood flow imaging in clinical settings. However, they inherently estimate the velocity component only in the axial direction. Therefore, various studies of angle-independent methods have been conducted. The multi-angle Doppler method is one such angle-independent method, in which the velocity vector is estimated using axial velocities obtained from multiple directions by steering an ultrasonic beam. Recently, plane wave imaging, which realizes a very high frame rate of several thousand frames per second, was applied to the multi-angle Doppler method. However, the maximum detectable velocity, i.e., the aliasing limit, was reduced depending on the number of steering angles. In the present study, the feasibility of a specific transmit sequence, namely, the repeated transmit sequence, was examined using the plane-wave multi-angle Doppler method. Method In the repeated transmit sequence, plane waves were emitted to the same direction twice, after which the steering angle was changed. By repeating the same procedure, a pair of beamformed radio-frequency (RF) signals could be obtained under each beam steering angle. By applying the autocorrelation method to each pair of RF signals, the time interval between the RF signals could be kept as the pulse repetition interval (PRI). The feasibility of such a transmit sequence was examined by numerical simulation and in vivo measurement of a human carotid artery. ResultsThe simulation results showed that the maximum steering angles of over 10 degrees were not feasible with the linear array used in the present study. The feasible maximum steering angle would depend on the element pitch of the probe relative to the ultrasonic wavelength. By limiting the maximum steering angles to 5 and 10 degrees, bias errors were 9.2% and 11.3%, respectively, and root mean squared errors were 21.5% and 16.9%, respectively. Also, flow velocity vectors in a human carotid artery could be visualized with the proposed method. ConclusionThe multi-angle Doppler method was implemented in plane wave imaging with the repeated transmit sequence, and the proposed method was shown to be feasible through numerical simulation and in vivo measurement of a carotid artery.

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Section: Discussionmentioning

confidence: 99%

Measurement of flow velocity vectors in carotid artery using plane wave imaging with repeated transmit sequence

et al. 2021

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“…The diameter of red blood cells on the order of 5–7 μm is suitable for Rayleigh scattering of ultrasonic frequency between 1 and 10 MHz because the scattering of red blood cells is large enough, so the ultrasonic backscattering signal considers a Gaussian random process. [ 32 72 ] Different concentrations of Sephadex particles have been applied in water,[ 68 73 ] also in glycerin mixture. [ 21 ] The size of Sephadex particles is in the range between 20 and 80 μm and its diameter is greater than red blood cells.…”

Section: T Ypes Of S Uspension mentioning

confidence: 99%

A review of suspension-Scattered particles used in blood-mimicking fluid for doppler ultrasound imaging

et al. 2018

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Doppler ultrasound imaging system description and calibration need blood-mimicking fluids (BMFs) for the test target of medical ultrasound diagnostic tools, with known interior features and acoustic and physical properties of this fluid (BMF). Physical and acoustical properties determined in the International Electrotechnical Commission (IEC) standard are specified as constant values, the materials used in the BMF preparation should have values similar to the IEC standard values. However, BMF is ready-made commercially from a field of medical usage, which may not be appropriate in the layout of ultrasound system or for an estimate of novel imaging mechanism. It is often eligible to have the capability to make sound properties and mimic blood arrangement for specific applications. In this review, sufficient BMF materials, liquids, and measures are described which have been generated by utilizing diverse operation mechanism and materials that have sculptured a range of biological systems.

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“…3) which had a real-time fast Fourier transform (FFT) processor board installed. This board was kindly prepared for us by collaborators at the University of Florence, and has been previously described [17]. The transducer assembly was operated in two different modes.…”

Section: Systemmentioning

confidence: 99%

Three-dimensional vector flow estimation using two transducers and spectral width

Newhouse

Dickerson

Cathignol

et al. 1994

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

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Current ultrasonic blood flow measurement systems estimate only that component of Row which is parallel to the incident ultrasound beam. This is done by relating the mean backscattered frequency shift to the axial velocity component through the classical Doppler equation. A number of ultrasonic techniques for estimating the two-dimensional (2-D) blood velocity vector have been published, both Doppler and non-Doppler.Several three-dimensional (3-D) blood velocity vector techniques have also been proposed, all of which require a multiplicity of transducers or lines of sight. Here a technique is described for estimating the total velocity vector, using only two transducers. This is achieved by measuring not only the frequency shifts but also the bandwidths of the back-scattered spectra, making use of the fact that the bandwidth of a Doppler spectrum has been shown to be proportional to the velocity component normal to the sound beam. Partial experimental verification of the proposed vector flow estimation scheme is demonstrated by using a constant velocity thread phantom.

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Clinical evaluation of a new anti-aliasing technique for ultrasound pulsed Doppler analysis

Cited by 19 publications

References 14 publications

Measurement of flow velocity vectors in carotid artery using plane wave imaging with repeated transmit sequence

Measurement of flow velocity vectors in carotid artery using plane wave imaging with repeated transmit sequence

A review of suspension-Scattered particles used in blood-mimicking fluid for doppler ultrasound imaging

Three-dimensional vector flow estimation using two transducers and spectral width

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