Читать книгу Interventional Cardiology - Группа авторов - Страница 236

With the exception of the left main stem, coronary arteries are muscular arteries and are histologically organized into three layers. The intima consists of a lining layer of endothelial cells supported by a subendothelial layer [13], which is exceedingly thin at birth and grows progressively with age, eventually reaching OCT resolution limits [14]. In OCT, the intima can be visualized as a signal‐rich luminal layer. The intimal thickens with age, and nearly all adult coronaries display an extent of intimal thickening [15]. There is no established cut‐off for the identification of pathologic intimal thickening; however, some authors use, rather arbitrarily, a cut‐off of 300 μm to identify intimal thickening, and above 600 μm for pathologic intimal thickening in the absence of a lipid pool or calcified region >1 quadrant [16]. The medial layer is a signal‐poor region isolated from the intimal layer and the adventitia by the brighter lines of the internal and the external elastic membrane, respectively [17]. The adventitia is recognized as a heterogeneous high signal outer layer.