Advances in technology now allow IVUS to characterize the morphology and composition of plaques. Specifically, the analysis of the IVUS wave frequency - beyond the interpretation of wave lengths used in grayscale IVUS- enables in vivo analysis of atherosclerotic plaque composition with high sensitivity and specificity. Although previous studies have reported data using IVUS radiofrequency analysis, the use of a new modality (iMapTM, Boston Scientific, Santa Clara, CA, USA) for characterization of atherosclerotic plaque is poorly known.