|View:||Color Right ICA Prox|
|Measurement:||RICA Prox – Peak/end diastolic velocity|
Adjusting the color box will adjust the direction of the Doppler beam.
In this image, by adjusting the color box the direction of the Doppler beam changed. By changing the Doppler beam and correcting, the angle to display parallel to the vessel the Doppler angle changed from 55° to 60°.
Changing the angle correction to remain parallel to the vessel.
In this image, the angle correction was adjusted to run parallel to the vessel wall. The angle changed from 55° to an acceptable 45°.
It is drilled in us from the time we start learning in the classroom that the Doppler cursor should be aligned parallel to the vessel walls and Doppler angles should be maintained between 45°- 60° whenever possible. The Society of Vascular Ultrasound notes that occasionally, due to patient anatomy, Doppler angles that are less than 45° may be encountered and they recommend that we note this on the worksheet. Just how much does angle affect the velocity readings??
Below are examples from SonoWorld.com of the same vessel measured at 30° and 50°. You can see the difference in velocity readings.
Velocity: 81 cm/sec
Velocity: 114 cm/sec