procedure, and the fact that it is considered an interventional procedure, and should only be performed by angiographers that are trained in interventional cardiology techniques. In addition, there may be additional risk imposed by the use of the IVUS catheter. The computerized IVUS echocardiographic imaging systems list for $120,000, US, 2007 for a cart based system and ~$70,000 for an installed or integrated solution. The disposable catheters used to do each examination typically cost ~$600, US, 2007. In many hospitals, the IVUS system is placed as part of a bundle deal based on minimum disposable sales volumes. In other words, the cost of the console is paid for by rebates from other purchased products including IVUS catheters. Because no standard exists, IVUS catheters cannot be interchanged between different manufacturers. Additionally, IVUS adds significant additional examination time and some increased risk to the patient beyond performing a standard diagnostic angiographic examination. This increase is significantly less when IVUS is part of a percutaneous coronary intervention, since much of the setup is the same for the intervention as for the IVUS imaging. IVUS continues to improve and some manufacturers have proposed building IVUS technology into angioplasty and stent balloon catheters, a potential major advance, but limited by complexity, cost and increased bulk of the catheters. Comparison versus intravascular optical coherence tomography Compared to IVUS, intravascular OCT offers an order of magnitude improved resolution for a better visualization of vessel lumen, tissue microstructure and devices (e.g., intracoronary stents). IVUS offers an improved imaging depth for the assessment of lipid or necrotic plaques, while intravascular OCT offers better penetration and enhanced imaging of calcific tissue. Intravascular OCT requires a short injection of contrast (e.g., 2 to 3 seconds) in a similar way to obtain an angiographic image. IVUS does not require a contrast injection as ultrasounds can penetrate through blood. Method To visualize an artery or vein, angiographic techniques are used and the physician positions the tip of a guidewire, usually 0.36 mm (0.014") diameter with a very soft and pliable tip and about 200 cm long. The physician steers the guidewire from outside the body, through angiography catheters and into the blood vessel branch to be imaged. The ultrasound catheter tip is slid in over the guidewire and positioned, using angiography techniques so that the tip is at the farthest away position to be imaged. The sound waves are emitted from the catheter