Titlebook: Basic Concepts in Doppler Echocardiography; Methods of clinical J. V. Chapman,A. Sgalambro Book 1987 Martinus Nijhoff Publishers, Dordrech

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Intracardiac Flow Dynamics,at the ratio of the pressure gradient (PI - P2) to flow (Q) is a function of the tube dimensions and the viscosity (μ) of the moving fluid:.where r is the radius of the tube and L is the length of the tube. The ratio of pressure gradient (PI - P2) to flow (Q) is also defined as the vascular resistan

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Doppler Ultrasound in Congenital Heart Disease,as the sole means of obtaining the data needed to derive this ratio. The Doppler estimation of the flow ratio involves the systematic interrogation of flow across the semilunar valves until a good quality flow velocity curve is recorded. The flow velocity curve should have a narrow spectral bandwidt

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On the Design of 2D Flow Imaging Systems,ear to stand still, except if you observe them over a periode of time so you can see that they have moved. The same is true if we want to determine a Doppler shift in frequency of an ultrasonic echo: The accuracy of the frequency estimate, Df, is inversely proportional to the time we observe the signal, T.

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https://doi.org/10.1007/978-3-658-30147-7 to the anatomic structures, it is often necessary to interrogate flow from several transducer positions in order to record the true peak flow velocity. When obstruction is present, the value of the peak flow velocity may differ markedly from one imaging window to another.

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https://doi.org/10.1007/978-3-658-30147-7flow is present, an increase in red cell velocity will occur. By accurately recording the peak transvalvular flow velocity, the pressure gradient existing across the valve can be estimated noninvasively.

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