Doppler (carotid arteries. arteries and veins of the arms and legs) is a special ultrasound technique that evaluates blood flow through  blood vessels.

Vessels that can be evaluated are in the neck (carotid arteries), major arteries in the abdomen as well as arteries and veins in the arms and legs.

Doppler studies are performed to rule out clots or thrombus in the veins as well as detect if there are any plaque or narrowing the arteries. Abnormal blood flow can be detected.