Visualization of Internal Carotid Artery Atherosclerotic Plaques in Symptomatic and Asymptomatic Patients: A Comparison of Optical Coherence Tomography and Intravascular Ultrasound

Representative images of neovascularization and ulceration of symptomatic carotid artery stenosis before CAS. A, OCT demonstrates neovascularization as a no-signal-intensity microchannel structure without connection to the vessel lumen that was present in >3 continuous cross-sections of OCT images (arrow). B, The corresponding image from IVUS does not show these findings. C, OCT demonstrates a small ulceration as a cavity with a lacerated superficial intimal layer (arrow). D, The corresponding image from IVUS does not depict this lesion. Bar = 1 mm.

Representative images of a calcification and lipid-rich component before stent placement. A, OCT demonstrates calcification as a heterogeneous, sharply delineated mixed-signal-intensity region (arrowheads). B, The corresponding image from IVUS shows calcification (arrowheads) as an echo-bright area with acoustic shadowing, but unclear borders. C, Corresponding VH-IVUS reveals white calcifications (arrows). D, OCT demonstrates a large lipid pool (arrow) as a homogeneous diffusely bordered signal-intensity-poor region with an overlying signal-intensity-rich band corresponding to a fibrous cap. However, OCT does not demonstrate the entire arterial wall due to the limited penetration depth. E, Corresponding IVUS shows the plaque as heterogeneous with an echolucent core (arrow). F, Corresponding VH-IVUS reveals a large light-green lipid core (arrow). Bar = 1 mm.