What is Doppler ultrasound?

Doppler ultrasound is a non-invasive imaging technique that uses sound waves to measure the velocity of blood flow within blood vessels. It works by detecting the change in frequency of the ultrasound waves reflected from moving blood cells, known as the Doppler effect. It is commonly used to diagnose conditions such as deep vein thrombosis, arterial stenosis, and fetal health monitoring by assessing blood flow in the umbilical cord.