Overview
Although angiography remains the gold standard for diagnosing the presence and severity of a coronary artery lesion, it often does not reveal the full extent of coronary artery disease. In some patients, an additional examination technique is required to accurately examine an area of the coronary tree and obtain an individualized, optimal result.
Two intracoronary imaging techniques are available for clinical use:
- Intravascular ultrasound (IVUS): IVUS facilitates the assessment of blood vessel morphology. Using IVUS, the wall of the coronary vessel is visualized in cross-section. Thus, the structure of a vessel wall can be accurately assessed and the size of the vessel can be measured. IVUS also allows assessment of the vessel during and after stent implantation.
- Optical Coherence Tomography (OCT): With a resolution of 10-20 microns, OCT provides high-resolution cross-sectional images of the vessel wall. These images allow precise analysis of the nature and composition of a plaque and the morphology of the vessel wall. In addition, OCT is used for procedural planning and as a control after stent implantation to ensure an optimal result.
Figure Optical coherence tomography (OCT): A. Visualization of the right coronary vessel with contrast medium before the procedure (coronary angiography). Star: contrast medium in the vessel. Thick arrow: vascular calcification (atherosclerotic plaque). Head of arrow: guiding catheter. B. Cross-section of vessel at the site of vascular calcification in OCT imaging. Star: Blood flow through the vessel. Thick arrows: ruptured plaque (plaque rupture) in the vessel wall. Thin arrows: Vessel wall. Arrowhead: