Modern Imaging Techniques for Percutaneous Coronary Intervention Guidance: A Focus on Intravascular Ultrasound and Optical Coherence Tomography

: The use of imaging during percutaneous coronary intervention (PCI) can improve the outcomes by giving key information in every phase of the procedure. It can improve the knowledge of plaque composition thus helping the subsequent technical strategy; it can precisely define the measure of the stent to implant; it can assess in detail the correct positioning of the stent (apposition, expansion, and full coverage of the atherosclerotic plaque); it helps in recognizing the complications that may occur after stenting (e.g., edge dissection or tissue/thrombus protrusion in the stent area). Further, it could help evaluation for both diagnostic and therapeutic purposes of angiographic unknown or questionable findings [e.g., spontaneous coronary artery dissection (SCAD), characterization of mycotic aneurysm and pseudoaneurysm]. In the follow up phase, the use of intracoronary imaging may significantly improve the understanding of the mechanisms leading to the procedural failure. What this review adds is to describe the similarities and differences between intravascular ultrasound (IVUS) and optical coherence tomography (OCT) technologies, to highlight the evidence supporting their utility to improve PCI outcomes, to give practical advice and tools on daily interventional routine, to show a point of view on future perspectives and integration with artificial intelligence (AI).