Table 3. A summary for positron emission tomography tracers used for Alzheimer's disease.

Target	Generation	Tracers	Note
Aβ: amyloid-β protein; 18F: 18fluorine; 11C: 11carbon; PIB: Pittsburgh compound B; FDDNP: 2-(1-{6-[(2-fluoroethyl)(methyl)amino]-2-naphthyl}ethylidene)malononitrile; PBB3: pyridinyl-butadienyl-benzothiazole 3; FDA: Food and Drug Administration.
Aβ
Planar heteroaromatic analogs	1	11C-PIB[119–123]	Classical used tracer
	1	18F-flutemetamol[124–125]	FDA approved
	1	18F-florbetapir[113]	FDA approved
	1	18F-florbetaben[113]	FDA approved
	2	18F-flutafuranol[126,128–131]
Tau
Naphthalene analogs	0	18F-FDDNP[134–135]	Affinity for both Aβ and Tau
Arylquinoline derivatives (THK series)	1	18F-THK-523[137]
	1	18F-THK-5105[138]
	1	18F-THK-5117[138]
	1	18F-THK-5351[140]
Benzimidazole pyrimidines derivatives	1	18F-flortaucipir[141–142,144]	FDA approved
	2	18F-RO948[148]
	2	18F-PI2620[149]
	2	18F-GTP1[147]
PBB	1	11C-PBB3[145]
	2	18F-PM-PBB3[150–151]
Azaindole derivatives	2	18F-MK6240[152–153]
Naphthyridine derivatives	2	18F-JNJ311[154–155]