|Tracer||Pathological Process||Biological Target||Research Application and Limitations|
|18F-FDG||Inflammation||Glucose analogue||Increased uptake seen in carotid disease (46), but myocardial uptake limits its use in coronaries.|
|18F-NaF||Microcalcification||Hydroxyapatite||Increased uptake demonstrated in both culprit coronary and carotid plaque (61). Limited myocardial uptake, but overspill from bones can affect interpretation.|
|Ga68- or Cu64-DOTATATE||Inflammation||Somatostatin receptor subtype-2 (SSTR2)||Localizes to culprit coronary and carotid plaque (53). No physiological uptake in the myocardium. In some cases lack of availability limits its use even in research. Further validation studies are needed.|
|11C-PK11195||Inflammation||Translocator protein (TSPO)||Increased uptake in culprit carotid plaques following stroke, independent of vessel stenosis (55). Limited by high nonspecific binding and short half-life. Further validation studies are needed.|
|USPIO||Inflammation||Surface scavenger receptors||Has been used in magnetic resonance imaging, with uptake demonstrated in culprit carotid plaques and asymptomatic carotid stenoses (39,40). High blood pool signal may affect signal interpretation.|
18F-FDG = 18F-fluorodeoxyglucose; 18F-NaF = 18F-sodium fluoride; USPIO = ultrasmall superparamagnetic iron oxide.