technical points
Last reviewed 01/2018
Pulsed doppler enables the determination of blood velocity at any point along the path of the beam and so is useful in locating a defect.
Continuous wave doppler is better for high velocity jets as seen in aortic stenosis.
Real-time colour doppler displays a colour representation of doppler shifts over a moving ultrasound image. Trained observers can quickly distinguish the patterns of normal and abnormal blood flow.
Practically, pressure gradients can be estimated from the determination of jet velocity:
Pressure gradient = 4 x peak velocity^2
(Pressure in mmHg and velocity in m/s)