The ultrasound machine includes a computer, a video screen, and a transducer, which is a hand-held device that sends and receives ultrasound waves into and from the body.
You will lie down on your back on an exam table for the test. Your technician or doctor will put a gel on your neck where your carotid arteries are located. This gel helps the ultrasound waves reach the arteries better. Your technician or doctor will put the transducer against different spots on your neck and move it back and forth.
The transducer gives off ultrasound waves and detects their echoes after they bounce off the artery walls and blood cells. Ultrasound waves can’t be heard by the human ear.
A computer uses the echoes of the ultrasound waves bouncing off the carotid arteries to create and record images of the insides of the arteries (usually in black and white) and your blood flowing through them (usually in color; this is the Dopper ultrasound). A video screen displays these live images for your doctor to review.