This test, performed during a cardiac catheterization, is used to evaluate blockages of the coronary arteries. A miniature ultrasound transducer on the tip of a catheter is guided through the coronary arteries, where it sends and receives sound waves (similar to an echocardiogram) to create a detailed images of the inside of the vessel.  

 
The intravascular ultrasound is not a method for diagnosing coronary artery disease. It is used to provide specific information about the coronary artery blockage, including its location, size and shape. This information can help doctors select the best treatment option, determine the size of the stent and balloon, as well as identify the best location for the stent.