AJR. American journal of roentgenology
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AJR Am J Roentgenol · Sep 1988
ReviewThe Doppler signal: where does it come from and what does it mean?
Doppler sonographic measurement of blood velocity and associated physiologic parameters is a powerful diagnostic technique. State-of-the-art instrumentation incorporates velocity measurement with two-dimensional imaging capability; it uses intensity and color coding to display complex physiologic and anatomic data to the observer in an easily understood format. Although the concepts underlying Doppler sonography are not complex, mastery of the technique requires extra training and commitment. ⋯ Doppler sonographic measurements may be used to determine the presence of flow, determine the direction of flow, identify time-varying velocity characteristics, and detect velocity disturbances. Because flow and velocity are related, it is possible to estimate flow from velocity measurements with careful calibration and proper precautions. Velocity is related to flow, which, in turn, is related to both pressure and vascular resistance.(ABSTRACT TRUNCATED AT 400 WORDS)