Doppler Ultrasound (Arteries vs Veins)

[@jxij99]

love your video. Great content

[@黃紹閔]

may I ask why artery on CW usually has a positive doppler shift? when we open the transducer, is it set purposely by manufacture? The anatomy of artery/vein doesn't always have a positive/negative vector from our probe.

[@SonographyMinutes]

I’m not an echo tech, so I have limited knowledge of CW spectral Doppler (it’s primarily used in Echo). I use PW spectral Doppler for General and Vascular Ultrasound. But my understanding is that CW spectral Doppler is not measuring the Doppler signal within a fixed point like PW does. CW captures the Doppler signals across a wide region (all along the ultrasound beam, from the top of the ultrasound image to the bottom of the ultrasound image). Since it is measuring signals from such a wide area, and direction of flow can vary within the wide region, the machine determines direction of flow by determining which direction of flow is represented the most within the ultrasound beam. If most of the signals along the ultrasound beam are positive Doppler shifts and only a small portion of the beam are negative Doppler shifts, the machine will display the CW signal as a positive Doppler shift. So it may be that flow towards the transducer is more prevalent within the wide regions that you are sampling, resulting in flow information displaying as a positive Doppler shift.

[@黃紹閔]

Thanks for detailed reply. So can I rely on "positive CW is usually artery" or always check conpressibility or PW waveform

[@SonographyMinutes]

@@黃紹閔 I don’t know the answer to that actually. I never use CW spectral Doppler.

[@kavikavi-fb6je]

Mam in my venous Doppler report enlarged superficial inguinal nodes with preserved fatty hilium is it normal or not.

[@maysamalih88]

Greatly explained... thans

[@SonographyMinutes]

Thanks so much!

[@nausheenasif2467]

Great👍👍

[@SonographyMinutes]

Thanks for the visit!