Intracoronary OCT plaque characterization

(A) Concentric fibrous plaque. Fibrous tissue appears signal rich, bright yellow. The signal-poor, dark media is not discernible anymore. The adventitial border as well as periadvential tissue can be seen.
(B) Eccentric fibrous plaque in 9 to 12 o'clock position with focal calcification appearing as a signal poor, dark structure with sharply delineated borders (dotted line).
(C) Eccentric fibrofatty plaque in 12 to 6 o'clock position showing typical gradual diminishing of the OCT signal towards the adventitia.
(D) Eccentric lipid-rich plaque in 7 to 12 o'clock position. Typically a fibrous cap can be recognized as signal rich, yellow structure towards the lumen with a rapid drop in signal intensity towards the abluminal plaque side (arrows), caused by the high attenuation of lipid-rich tissue.