OCT features of high-risk atherosclerotic plaque associated with ¹⁸F-NaF PET uptake. The region of increased ¹⁸F-NaF activity in the left anterior descending artery (left), green arrow, is imaged with OCT (right). This region has multiple high-risk plaque features on OCT. Adapted with permission from Bellinge et al.¹⁰³ White arrow indicates cholesterol crystals; red arrow indicates microcalcifications; blue arrow indicates lipid-rich plaque.