Intravascular ultrasound (IVUS) is used to help diagnose coronary artery disease. IVUS uses high-frequency sound waves to create a motion picture of the interior of your coronary arteries. In the cardiac cath lab, a device called a transducer is attached to a catheter, and threaded through an artery into your heart. The transducer sends out sound waves that bounce off the artery structures and return as echoes. These echoes are converted into images on a monitor.