Perspectives on the rational integration of intravascular imaging and physiology into the current cath lab environment

It is now more than two decades since Nico Pijls and Bernard DeBruyne introduced fractional flow reserve (FFR) as a way to assess stenosis severity in the catheterization laboratory and since Paul Yock invented grayscale intravascular ultrasound (IVUS) that then spawned many second-generation intravascular imaging techniques such as (1) Virtual histology-IVUS (VH-IVUS) that uses both amplitude and radiofrequency ultrasound information to classify plaque as necrotic core,fibrofatty,fibrotic,or calcific;(2) Optical coherence tomography (OCT) that is the light analogue of IVUS with a 10-fold increase in resolution and better tissue characterization,but at the expense of decreased penetration;(3) Near infrared spectroscopy (NIRS) that detects lipid within the vessel wall within 0.45 mm of the neointimal surface and that has been recently combined with grayscale IVUS in a single catheter.