Table 1.

Criteria for plaque characterization in VH and OCT

Lesion type	Brief description in VH [37]	Brief description in OCT [34, 35]
Intimal thickening	Plaque with <10% of NC and <10% of calcified tissue	Homogeneous signal-rich region
Fibroatheroma	Plaque with >10% of confluent NC	Heterogeneous signal poor regions poorly delineated
Fibrocalcific plaque	>10% of confluent DC with <10% of confluent NC	Homogeneous sharply delineated signal poor regions
Complicated lesion	–	Rupture: discontinuous cap over visible cavity Thrombus: irregular mass protruding into lumen

NC necrotic core, DC dense calcium. No criteria exist for complicated lesions seen with VH; of the complicated lesions defined in the AHA classification, rupture and thrombus (but not hemorrhage) are defined for OCT. Fibroatheromas often also contain calcifications; lesions that contained both significant necrotic core and calcification, were categorized as fibroatheroma