Introduction

Over the past decade, several studies and clinical trials highlighted the central role of optical coherence tomography (OCT) in the management of coronary artery disease and percutaneous coronary intervention (PCI), moving OCT from the bench to the bedside during routine coronary procedures [ , ]. However, the OCT benefits such as high spatial resolution, cross-sectional visualization of endothelial, subendothelial, and intraluminal structures, along with 3D reconstruction of the vessel, can only be achieved in a blood-free environment, as blood flow strongly scatters light and attenuates the OCT signal. Hence, a manual or mechanical intracoronary contrast injection is required to properly clear the vessel lumen during OCT pullback acquisition. Usually, the contrast injection rate is set at 4 mL/s for a total volume of 14–16 mL for the left coronary artery and 3 mL/s for a total volume of 12–14 mL for the right coronary artery, interrupting contrast injection immediately when the guide catheter is seen at OCT pullback image. As a result, the blood clearance needed for OCT image acquisition increases the volume of iodine-contrast used during the procedure, especially when repeated OCT images are necessary.