Effect of machine parameters on variance display in Doppler color flow mapping

Utsunomiya, Toshinori; Ogawa, Toshio; King, ST; Sunada, Eric; Moore, Glenis; Henry, Walter L.; Gardin, Julius M.

doi:10.1016/0002-8703(90)90254-u

Cited by 16 publications

(3 citation statements)

References 5 publications

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“…↑NQ will ↓RJA because low velocity flows filtered out; ↓NQ will ↑RJA because lower velocity flows included. 4 Standardize by keeping NQ between 40 and 50 cm/sec. 5 (c) Driving pressures across MV.…”

Section: • Limitations and Optimal Utilizationmentioning

confidence: 99%

Transthoracic and Transesophageal Echocardiographic Assessment of Mitral Regurgitation Severity: Usefulness of Qualitative and Semiquantitative Techniques

et al. 2005

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In this report, we review the advantages, limitations, and optimal utilization of various transthoracic and transesophageal echocardiographic (TTE and TEE) methods used for assessing mitral regurgitation (MR) as published in full-length, peer-reviewed articles since the color Doppler era began in 1984. In addition, comparison is made to other imaging modalities including catheter-based, magnetic resonance and surgical assessment of MR. Although left ventricular (LV) angiography has been traditionally used for validation of various TTE methods and is time-honored, its considerable limitations preclude it from being a real "gold standard." Based on the reviewed literature, no clear "gold standard" for the assessment of MR can be identified at present, but newly emerging TTE and TEE techniques, such as three-dimensional color Doppler, may have the potential to overcome some of the limitations of the two-dimensional methods.

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Section: • Limitations and Optimal Utilizationmentioning

confidence: 99%

Transthoracic and Transesophageal Echocardiographic Assessment of Mitral Regurgitation Severity: Usefulness of Qualitative and Semiquantitative Techniques

et al. 2005

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“…Recognition of an anterior origin of the jet might be missed, if the plane is not eccen tric enough or the imaging delayed in diastole. Three main factors might also lessen Doppler imaging: namely, technological and pathophysiological factors [23,24], also…”

Section: Limitationsmentioning

confidence: 99%

Compared Locations of the Regurgitant Aortic Jets at Their Origin and in the Left Ventricle: A Doppler Approach to the Underlying Type of Aortic Orifices in Adult Patients

Veyrat¹,

Beuve²,

Bas³

et al. 1993

Am J Noninvas Cardiol

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Echocardiography is often at failure to assess a tri- or bicuspid type of orifice in aortic regurgitation on patients over 50 years old. We hypothetized that the sites of the Doppler flow areas at the aortic orifice (AO-O) in connection with the normal, in case of tricuspid, or abnormal commissural closure line, in case of bicuspid orifices, might entail different directions of regurgitant jets in the left ventricular outflow tract (LVOT) leading to this assessment. Doppler onsets and locations of jet origin (JO) at the AO-O in the long and short aortic views and of regurgitant jets in the LVOT in the long-axis view were studied in order to determine their locations - anterior, central or posterior - and if these locations were similar or not at both sites. Data were reviewed and correlated with the number of cusps on 53 patients operated for aortic regurgitation. There were 83% tri- and 16.9% bicuspid valves. In 43 patients with tricuspid AO-O, similar locations were found between JO, having a central onset, with or without an anterior or posterior spreading, and jets in the LVOT: central 38%, anterior 9%, posterior 53%. In 10 patients, there was discrepancy between an eccentric onset of JO and the direction of jets in the LVOT, spreading towards the opposite location. Nine of these patients had bicuspid AO-O. There was 1 false-positive bicuspid AO-O (sensitivity and specificity ranging from 90 to 100%). Thus, coupling both the imaging of the regurgitant jet at the AO-O and the LVOT is a reliable method to rapidly assess the underlying type of AO-O, whatever the age and the calcifications.

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“…Technical factors related either to the instrumentation or to the physics of ultrasound and a variety of physiological factors in addition to the volume of regurgitation and the entrainment of the surrounding fluid in the receiving chamber can influence the quantitation of valvular insufficiency by the color Doppler techniques (10,(12)(13)(14)(15).…”

mentioning

confidence: 99%

A pulsatile flow model for in vitro quantitative evaluation of prosthetic valve regurgitation

Giuliatti

Gallo

Almeida-Filho

et al. 2000

Braz J Med Biol Res

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A pulsatile pressure-flow model was developed for in vitro quantitative color Doppler flow mapping studies of valvular regurgitation. The flow through the system was generated by a piston which was driven by stepper motors controlled by a computer. The piston was connected to acrylic chambers designed to simulate ventricular and atrial heart chambers. Inside the ventricular chamber, a prosthetic heart valve was placed at the inflow connection with the atrial chamber while another prosthetic valve was positioned at the outflow connection with flexible tubes, elastic balloons and a reservoir arranged to mimic the peripheral circulation. The flow model was filled with a 0.25% corn starch/water suspension to improve Doppler imaging. A continuous flow pump transferred the liquid from the peripheral reservoir to another one connected to the atrial chamber. The dimensions of the flow model were designed to permit adequate imaging by Doppler echocardiography. Acoustic windows allowed placement of transducers distal and perpendicular to the valves, so that the ultrasound beam could be positioned parallel to the valvular flow. Strain-gauge and electromagnetic transducers were used for measurements of pressure and flow in different segments of the system. The flow model was also designed to fit different sizes and types of prosthetic valves. This pulsatile flow model was able to generate pressure and flow in the physiological human range, with independent adjustment of pulse duration and rate as well as of stroke volume. This model mimics flow profiles observed in patients with regurgitant prosthetic valves. Key wordsSpectral and especially color Doppler flow mapping techniques have been used extensively in the clinical setting to estimate noninvasively the severity of valvular regurgitation (1-5). A number of different Doppler methods for quantitation of valve regurgitation have been described, including measurement of the spatial distribution of regurgitant jets in the receiving chamber (3,6), quantitation of regurgitant flow rate using flow convergence proximal to the orifice (7,8), momentum flux analysis (9), and dimensions of vena contracta (10,11).An improved understanding of the interrelations between flow mapping and hydrodynamics has brought to light important limi-

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Effect of machine parameters on variance display in Doppler color flow mapping

Cited by 16 publications

References 5 publications

Transthoracic and Transesophageal Echocardiographic Assessment of Mitral Regurgitation Severity: Usefulness of Qualitative and Semiquantitative Techniques

Transthoracic and Transesophageal Echocardiographic Assessment of Mitral Regurgitation Severity: Usefulness of Qualitative and Semiquantitative Techniques

Compared Locations of the Regurgitant Aortic Jets at Their Origin and in the Left Ventricle: A Doppler Approach to the Underlying Type of Aortic Orifices in Adult Patients

A pulsatile flow model for in vitro quantitative evaluation of prosthetic valve regurgitation

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