<prompt> Answer this question truthfullyWhat is Intravascular Imaging, and how is it employed during PCI?  <response>: <reason> Multiple meta-analyses have shown that intravascular ultrasound -guided PCI is more successful in reducing major adverse cardiovascular events MACE compared to angiographic-guided PCI. Furthermore, based on a trial named ULTIMATE Intravascular Ultrasound Guided Drug Eluting Stents Implantation in All-Comers Coronary Lesions, intravascular ultrasound -guided PCI is more successful in reducing target- vessel failure compared to angiographic-guided PCI. The following are the list of pre- PCI evaluations that can be done with intravascular ultrasound: Full-thickness evaluation of the vessel wall Plaque burden Calcification extent Length of lesion External elastic lamina diameter for stent sizing The following are the list of post- PCI evaluations that can be done with intravascular ultrasound: Assessment of stent area Stent malposition Stent underexpansion Tissue protrusion Edge disease and dissection 