The aim of this study was to evaluate a panel of endothelium-targeted microbubble (MB) ultrasound contrast agents bearing small peptide ligands as a human-ready approach for molecular imaging of markers of high-risk atherosclerotic plaque. Small peptide ligands with established affinity for human P-selectin, VCAM-1, LOX-1 and von Willebrand factor (VWF) were conjugated to the surface of lipid-stabilized MBs. Contrast-enhanced ultrasound (CEUS) molecular imaging of the thoracic aorta was performed in wild-type and gene-targeted mice with advanced atherosclerosis (DKO).