ABSTRACT
While traditional catheter-based angiography can provide detailed images of the vasculature not afforded by other modalities, it has fundamental limitations that the advent of intravascular imaging has sought to overcome, namely axial imaging of vascular lesions and information about their composition. This chapter discusses the two primary intravascular imaging modalities in catheter-based interventions: optical coherence tomography (OCT) and intravascular ultrasound (IVUS). The primary goal of this chapter is to convey a basic understanding of the capabilities of each of these devices and to conceptualize them comparatively to see that each modality has its strengths, weaknesses, and areas where it is most applicable and useful for informing interventions. OCT, being lauded for its superior resolution of vascular lesions, but limited by inability to image large vessels, finds a place in coronary and small-vessel peripheral (e.g., tibial) interventions for atherosclerotic occlusive disease. IVUS conveys the ability for interventionalists to image larger vessels (e.g., aorta, iliac) and the deeper layers of those vessels, but it has limitations in resolution and depicting complex lesions accurately.
