Optical coherence tomography: has its time come?
- Cardiovascular Biomedical Research Unit, Royal Brompton Hospital, London, UK
- Correspondence to Carlo Di Mario, Cardiovascular Biomedical Research Unit, Royal Brompton Hospital, Sydney Street, London SW3 6NP, UK;
Cardiologists using intravascular ultrasound (IVUS) towards the end of the past millennium can recall the time when enthusiasm for a method that was initially seen purely as a powerful research tool began to be substituted by the awareness that intravascular imaging had the potential to revolutionise our understanding of the mechanisms of coronary interventions. Such a revolution occurred in Milan when Antonio Colombo and his group applied ultrasound to elucidate the mechanism of stent thrombosis, at that time common despite high levels of anticoagulation.1
Many early adopters of optical coherence tomography (OCT) have a similar perception now. A research tool initially confined to the interest of a few connoisseurs has now achieved more widespread attention, including among some practitioners not previously known to be particularly interested in intravascular imaging. Such is the rapidity of the phenomenon that it has caught most OCT experts by surprise, as well as the few current manufacturers of commercially available systems. This change is mainly attributed to a recent technical development—namely, the increased acquisition rate allowed by frequency domain OCT. A rapid pull-back at a speed of 2 cm/s minimises the amount of contrast required to clear blood during image acquisition, with an average injection of 15–18 ml now required for the maximal imaging length currently available of 5.6 cm.2 3 A further reason, however, is often neglected. The crisp separation between vessel wall and lumen and the definition of stent struts provided by …