Doppler Ultrasound is a valuable medical imaging technique that uses sound waves to measure blood flow velocity and direction. It is widely used in obstetrics and the diagnosis and treatment of cardiovascular diseases. Doppler ultrasound is safe, noninvasive, and relatively inexpensive, but it has some limitations and requires a skilled operator to obtain accurate measurements.
Doppler Ultrasound may be used during pregnancy to evaluate blood flow to the mother's uterus or, more frequently, blood flow in the foetus. Blood flowing via veins appears differently from blood flowing through arteries. Unless the foetus is ‘practise' breathing or a harmful clinical scenario, like intrauterine growth restriction, prevails, venous flow is largely constant and unchanging throughout the cardiac cycle. However, arterial blood flow is very different. No matter which artery is being evaluated, the rate at which blood travels through it changes with each cardiac cycle.