. 2023 Aug 8;3(5):389–417. doi: 10.1021/acsbiomedchemau.3c00021

Table 3. General Overview and a Very Basic Comparison of PET and SPECT Modalities from Their Clinical Availability Perspective^a.

	SPECT	PET
Type of radioisotope used	Photon emitter	Positron emitter
Average half-lives of commonly used radioisotopes	Hours to days	Seconds to minutes^a
Examples of isotopes	^99mTc, ²⁰¹Tl, ¹³¹I, ¹¹¹In, ¹²³I, ¹³³Xe	¹⁸F, ¹¹C, ¹³N, ¹⁵O, ⁶⁸Ga
Spatial resolution	x	3x
Contrast resolution	x	2x
Signal noise:ratio	x	2x
Variety of ligands	Under development	Higher diversity
Availability	Widely available	Highly restricted
Sensitivity	High	Very high

Note that in preclinical application, long-lived radioisotopes such as ⁶⁴Cu (t_1/2 = 12.7 h), ⁸⁹Zr (t_1/2 = 3.27 days), and ⁵² Mn (t_1/2 = 5.59 days) are becoming more widely available.

Table 3. General Overview and a Very Basic Comparison of PET and SPECT Modalities from Their Clinical Availability Perspectivea.

Table 3. General Overview and a Very Basic Comparison of PET and SPECT Modalities from Their Clinical Availability Perspective^a.