For decades the only way of directly viewing the coronary arteries was through angiography. As discussed in the section on Cardiac Catheterization, a coronary angiogram is a shadow view of the coronary arteries that serves a dual purpose: diagnosis and treatment -- the continuous fluoroscopic TV image allows the interventional cardiologist to monitor the various wires, balloons and stents, as they are advanced towards the blockages.

But what if a tiny camera could be mounted on the front of the catheter as it is snaked up the aorta and into the left or right coronary artery? We could see a cross-sectional view of the blockage. Enter IVUS, or intravascular ultrasound. With the invention and refinement of IVUS, it is now possible to thread a miniaturized ultrasound transducer or "camera" into the coronary arteries to give a valuable cross-sectional view from the inside-out, showing the physician where the normal artery wall ends and the plaque begins.

Who Does the Procedure: Intravascular Ultrasound is done during an angioplasty by an interventional cardiologist in the catheterization laboratory with the cath lab team.

Patient Preparation: Since IVUS is seldom performed as a stand-alone imaging procedure, but as part of the angioplasty/stent procedure, no additional preparation is needed: the preparation is the same as for a Cardiac Catheterization.