Figure 3: Histological features of normal and atherosclerotic lesions in rabbits and the corresponding OCT images. (A1)–(A4): OCT and histology images of a normal vessel; (B1)–(B4): type-III plaque; (C1)–(C4): type-IV plaque. D1–D4: type-V plaque; (E1)–(E4): type-VI plaque; (F): lesion showing chronic total occlusion (CTO). The lumen is full of foam cells and lipid components; (G): medial neovessels in lesions with CTO. The neovessels (arrow) run longitudinally and contain red blood cells (RBCs). (H): A cholesterol crystal in a type-Va plaque. The cholesterol crystal looks like a spindle and accumulates into one part of the necrotic core; (I): intraplaque hemorrhage. RBCs have accumulated in the lipid pool. Staining is by Massonʼs trichrome (A2, B2, B4, C2, C3, D2–D4, E2–E4, and F–I), smooth muscle cell α-actin immunohistochemisty (A3 and B3), macrophage immunohistochemical identification (A4), and Picrosirius Red viewed under polarized light (C4). Original magnification of B2, C2, D2, and E2 is ×40; (A2)–(A4), (D3), (E3), and (F) is ×100. (B3), (B4), (C3), (C4), (D4), (E4), and (G)–(I) is ×400. M denotes the media; A, adventitia; FC, fibrous cap; LP, lipid pool; T, thrombus.