Intravascular ultrasound
![Intravascular ultrasound image of a coronary artery (left), with color-coding on the right, delineating the lumen (yellow), external elastic membrane (blue) and the atherosclerotic plaque burden (green). The percentage stenosis is defined as the area of the lumen (yellow) divided by the area of the external elastic membrane (blue) times 100. As the plaque burden increases, the lumen size will decrease and the degree of stenosis will increase.](/Images/godic/202501/20/IVUS_of_CAD5645.png")
![An IVUS image of the ostial left main coronary artery (left). The blue outline delineates the cross-sectional area of the lumen of the artery (A1 in the upper right corner), measuring 6.0 mm2. A two-dimensional mapping of the proximal LAD and left main coronary arteries is shown on the right.](/Images/godic/202501/20/IVUS-Tracing5646.png")
Intravascular ultrasound (IVUS) is a medical imaging methodology using a specially designed catheter with a miniaturized ultrasound probe attached to the distal end of the catheter. The proximal end of the catheter is attached to computerized ultrasound equipment. It allows the application of ultrasound technology, such as piezoelectric transducer or CMUT, to see from inside blood vessels out through the surrounding blood column, visualizing the endothelium (inner wall) of blood vessels in living individuals.