Copyright (c) 2018, StatPearls Publishing LLC. Intravascular ultrasound (IVUS) is an intravascular imaging modality primarily used in interventional cardiology to characterize lesion morphology, quantify plaque burden, guide stent sizing, assess stent expansion, and identify procedural complications.[1] Using a dedicated catheter with ultrasound-based technology an image is obtainable from inside an artery producing cross-sectional images with a 360-degree view of the vessel. This technology overcomes many of the limitations of angiography, which utilizes x-ray technology to produce a 2-dimensional lumenogram of a 3-dimensional structure. Rather than assessing the vessel from the outside as with angiography, IVUS provides the assessment from within the vessel.