Table 1.

Summary of major physical characteristics of beta-plus isotopes useful for PET imaging and positron annihilation lifetime spectroscopy (PALS) investigations. For isotopes that decay into excited states the properties of emitted gamma quanta are denoted. Data were adapted from [27]

Isotope	Half-life	${\mathit{\beta }}^{+}$ decay	$E_{\mathit{\gamma }}$ (MeV)	$E_{e^{+}}^{max}$ (MeV)	Excited nuclei lifetime
Isotopes for PALS and PET imaging
${}^{22}$Na	2.6 (years)	${}^{22}\text{Na}{\to }^{22}\text{Ne}+e^{+}+{\mathit{\nu }}_e+\mathit{\gamma }$	1.27	0.546	3.63 (ps)
${}^{68}$Ga	67.8 (min)	${}^{68}\text{Ga}{\to }^{68}\text{Zn}+e^{+}+{\mathit{\nu }}_e+\mathit{\gamma }$	1.08	0.822	1.57 (ps)
${}^{44}$Sc	4.0 (h)	${}^{44}\text{Sc}{\to }^{44}\text{Ca}+e^{+}+{\mathit{\nu }}_e+\mathit{\gamma }$	1.16	1.474	2.61 (ps)
Isotopes for PET imaging
${}^{68}$Ga	67.8 (min)	${}^{68}\text{Ga}{\to }^{68}\text{Zn}+e^{+}+{\mathit{\nu }}_e$	–	1.899	–
${}^{11}$C	20.4 (min)	${}^{11}\text{C}{\to }^{11}\text{B}+e^{+}+{\mathit{\nu }}_e$	–	0.961	–
${}^{13}$N	10.0 (min)	${}^{13}\text{N}{\to }^{13}\text{C}+e^{+}+{\mathit{\nu }}_e$	–	1.198	–
${}^{15}$O	2.0 (min)	${}^{15}\text{O}{\to }^{15}\text{N}+e^{+}+{\mathit{\nu }}_e$	–	1.735	–
${}^{18}$F	1.8 (h)	${}^{18}\text{F}{\to }^{18}\text{O}+e^{+}+{\mathit{\nu }}_e$	–	0.634	–