Pulsed Doppler: determination of blood velocity and volume flow in normal and diseased common carotid arteries in man.

A pulsed Doppler velocimeter with an adjustable range gated time system and a double transducer probe has been used to measure volume blood flow in 50 normal and 50 diseased common carotid arteries. A significant difference in mean volume flow between normal and diseased arteries was found (P less than 0.0001). On-line audio-frequency display of velocity signals were evaluated in each of the arteries together with angiographic description of the diseased arteries. Disturbance of the velocity profile develops before significant changes in volume flow or angiogram occur. Volume flow results and angiogram appearance relate best when the angiogram description is either of minimal disease or severe disease. Determination of dynamic flow conditions from structural appearance of arteries are not consistently dependable.