FRACTIONAL FLOW RESERVE (FFR)

Fractional flow reserve (FFR) is a technique used in coronary catheterization to measure pressure differences across coronary artery stenosis (narrowing, usually due to atherosclerosis) to determine the likelihood that the stenosis impedes oxygen delivery to the heart muscle (myocardial ischemia). It uses a pressure wire which detects pressure proximal and distal to stenosis and the physiological significance of the stenotic lesion is identified.

IVUS AND OCT

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.

IVUS is of use to determine both plaque volume within the wall of the artery and/or the degree of stenosis of the artery lumen. It can be especially useful in situations in which angiographic imaging is considered unreliable; such as for the lumen of ostial lesions, degree of calcification or where angiographic images do not visualize lumen segments adequately, such as regions with multiple overlapping arterial segments.

Similarly, Optical Coherence Tomography (OCT) uses light waves to see the plaque morphology. It is also useful post-stenting to confirm optimal expansion and deployment.