It is believed that most myocardial infarctions result from the rupture of "vulnerable plaques", that share certain common characteristics. These plaques typically consist of a lipid-rich core in the central portion of the thickened intima, covered by a thin friable fibrous cap. Today, one of the important challenges in the field of interventional cardiology is how to identify minor or silent plaques that carry the risk of thrombosis resulting in severe cardiac events. Current imaging technologies lack the resolution to reliably identify these lesions. OCT: Optical Coherence Tomography (OCT) might have the potential to fill this role. OCT is a new non-contact, light-based imaging modality providing in situ images of tissues at near histologic resolution. As shown in various preclinical and clinical reports, OCT allows the identification of mural as well as luminal morphologies including lumen dimensions, plaques, thrombi, dissections, tissue flaps as well as information on stent geometries including apposition and symmetry. Trials comparing intravascular ultrasound (IVUS) and OCT demonstrated that OCT provided additional morphologic information, which could be used to improve plaque characterization. OCT has the potential to provide a new and more detailed look into the vessel wall, which might help to identify plaques that are at risk of rupture, and furthermore, which will influence and guide the appropriate patient-specific therapeutic approach.