Table 3.

Characteristics of nanotargeted nuclear imaging modalities [20, 21].

Modality	Image probe (Amount of probe)	Type of radiation	Sensitivity	Spatial Resolution	Depth	Nanoparticle design
SPECT	99mTc, 111In etc	γ-ray	10−10-10−11 (pM)	0.5–1 mm	No limit	Surface
						Bio-conjugation
						or after loading
	loaded or labeled
	nanocarriers (ng)
PET	18F, 64Cu etc	Positron	10−11-10−12 (pM)	1-2 mm	No limit	Surface
						Bio-conjugation
						or after loading
	loaded or labeled	High energy
	nanocarriers (ng)	γ-ray

SPECT: single photon emission computed tomography; PET: positron emission tomography.