Table 1

PET radiotracers with potential value to track disease processes in AAA

Radiotracer ^(references)	Pathobiological process	Cellular target	Molecular target	Current clinical use	Applications and limitations
¹⁸F-FDG27–33	Inflammation	Macrophage	Glucose analogue	Yes—oncology, neurology and cardiology	Uptake influenced by local hypoxia and other resident cell types, therefore may have limited value. Widely used in cardiovascular research; has been studied in AAA disease
⁶⁸Ga-DOTATATE34–35	Inflammation	Macrophage	Somatostatin receptor (subtype 2)	Experimental	No physiological uptake seen in myocardium, therefore clearly detects macrophage accumulation
¹¹C-PK1119536	Inflammation	Macrophage	TSPO receptor	Experimental	Non-specific binding and low arterial signal density may preclude its use in clinical setting
GE18047	Inflammation	Macrophage	TSPO receptor	Experimental	Binding heterogeneity—10% of the population may lack binding potential due to variant in receptor
¹⁸F-FMCH37–39	Inflammation	Macrophage	Choline receptor	Yes—oncology	High uptake in liver may obscure analysis in suprarenal aorta. Lower tissue-to-background ratios than FDG, however, may identify areas of evolving inflammation distinct from areas of established calcification
¹⁸F-fluciclatide47	Angiogenesis	Endothelium, fibroblasts	Integrin α_vβ₃	Experimental	Has been investigated in autoradiography studies of AAA disease
¹⁸F-FMISO48	Hypoxia	Macrophage	Macromolecules in hypoxic cells	Experimental	Has been used in carotid studies
¹⁸F-HX448	Hypoxia	Macrophage	Macromolecules in hypoxic cells	Experimental	Has been used in carotid studies
¹⁸F-NaF46	Microcalcification	–	Hydroxyapatite	Yes—oncology	Overspill from nearby bone can interfere with uptake interpretation

AAA, abdominal aortic aneurysms; DOTATATE, ⁶⁸Ga-[1,4,7,10-tetraazacyclododecane-N,N′,N″,N′-tetraacetic acid]-d-Phe¹,Tyr³-octreotate; FDG, fluorodeoxyglucose; FMCH, fluoromethylcholine; FMISO, fluoromisonidazole; HX4, (3-[18F]fluoro-2-(4-((2-nitro-1H-imidazol-1-yl)methyl)-1H-1,2,3,-triazol-1-yl)-propan-1-ol); NaF, sodium fluoride; PET, positron-emission tomography; TSPO, translocator protein.