ABSTRACT
Optical coherence tomography (OCT) is an evolving intracoronary imaging modality that performs high-resolution cross-sectional images of biological structures, including coronary arteries. OCT is a catheter-based invasive imaging system that uses light instead of ultrasound. OCT catheter utilises a single optical fibre that both emits light and records the reflection from the coronary wall structures whilst simultaneously rotating and being pulled back along the artery. OCT is characterised by very high image resolution. The intensity of OCT signal is mapped into a colour scale that is displayed on a monitor. The main colours used are grey scale inverted grey scale, sepia scale, ranging from black through brown, gold, yellow and white and less commonly colour mappings. OCT is capable of defining the tri-laminar structure of the vessel with an accuracy comparable to histology. In OCT, the innermost layer is the intima which appears as high backscattering signal rich layer.
