Table 2.

Radioisotopes used for in vivo T-cell imaging/tracking and their physical characteristics

	Positron emitter	Half-life	Main β+/γ energy (Mev)	β+ decay (%)	Intrinsic spatial resolution loss (mm)	Production method
PET	18F	109.77 min	0.634	97	0.7	Cyclotron
	68Ga	67.71 min	1.899	88	2.4	Generator
	89Zr	78.41 h	0.900	23	1.0	Cyclotron
SPECT	99mTc	6.01 h	γ:0.141	IT	4.0	Generator

The most used radioisotopes for T-cell tracking in clinical application are reported. β⁺, positron decay; IT, isomeric transition