Vascular Doppler studies use ultrasound to evaluate the circulatory system by producing images of blood flow using sound waves transmitted through gel on the skin. There are several types of Doppler that image blood vessels in different ways and colors to show flow speed and direction. Doppler is used to detect blockages, clots, and other vascular abnormalities. It is a noninvasive and safe exam that provides real-time images of blood vessel function and blood flow without radiation. Abnormal results could indicate issues like blockages or abnormalities in blood vessel narrowing, widening, or flow.