What is a Intra-Vascular Ultrasound?

In the last several years, intra-vascular ultrasound (IVUS) has become the gold standard for detection of plaque in the coronary arteries and more precise quantification of blockages as well as plaque characterization. An IVUS, or sometimes called a intra-vascular echocardiogram is performed as a part of a cardiac catheterization.  IVUS is an ideal technology for studying the progression, stabilization and potential regression of the disease state. Unlike angiography, IVUS is able to image the inside of the vessel wall directly, allowing measurement of atheroma size, distribution and, to some extent, composition. The tomographical orientation of ultrasound enables visualization of the full 360* circumference of the vessel wall, so that lumen dimensions can be directly planimetered on a cross-sectional image. This allows precise assessment of the extent of disease in vessels that are often difficult to assess with angiography. IVUS also allows excellent resolution of structures within the arterial wall. It provides a reproducible, safe and sensitive method for assessing the development and extent of atherosclerosis, particularly in its earlier, pre-symptomatic stages.

How the test is performed:
The procedure takes place in a cath lab and you will be asked to wear a hospital gown. You will be given a mild sedative prior to the test to help you relax. Sometimes, admission the night before the test is required. Otherwise, you will be admitted as an outpatient or an inpatient the morning of the procedure.  A tiny ultrasound transducer is mounted to a guide wire, which is then selectively placed into each coronary artery.

How to prepare for the test:
Food and fluid are restricted 6 to 8 hours before the test. The procedure takes place in a cath lab and you will be asked to wear a hospital gown. Sometimes, admission the night before the test is required. Otherwise, you will be admitted as an outpatient or an inpatient the morning of the procedure.

Tell your doctor if you are allergic to seafood, if you have had a bad reaction to contrast material in the past, if you are taking Viagra, or if you might be pregnant.

How the test will feel:
The study is carried out in a laboratory by a trained cardiologist or radiologist and technicians or nurses.

You will be awake and able to follow instructions during the catheterization. A mild sedative is usually given 30 minutes before the procedure to help you relax. The procedure may last from 1 to several hours.

You may feel some discomfort at the site where the IV is placed. Local anesthesia will be used to numb the site, so the only sensation should be one of pressure at the site. You may experience some discomfort from having to remain still for a long time.

After the test, the catheter is removed. You might feel a firm pressure at the insertion site, used to prevent bleeding. If the IV is placed in your groin, you will usually be asked to lie flat on your back for a few hours after the test to avoid bleeding. This may cause some mild back discomfort.