Doppler ultrasound is an advanced imaging test that allows your physician to visualize blood flow within the arteries and veins of your arms and legs. It is one of several tests that can be employed to help diagnose and evaluate peripheral artery disease. Similar to other ultrasound exams, this is a painless, non-invasive procedure in which a technician moves a hand-held transducer device over the skin surface of the affected area. The transducer emits sound waves that bounce off of internal structures and create an image on a computer screen. This test can help reveal conditions such as blood clots, venous occlusion (a closed vein), a narrowed artery, atherosclerosis, venous reflux and others. It can also help in the evaluation of deep vein thrombosis, superficial thrombophlebitis and arteriosclerosis.