Table 1.

Commonly used single photon emitting radionuclides.

Radionuclide	Half-life	Energy	Mode of decay
Tc-99m	6.02 h	142 keV	IT (100%)
I-131	8.03 days	364 keV	β − (100%)
I-123	13.22 h	159 keV	EC (100)
In-111	2.80 days	171, 245 keV	EC (100%)

IT: isomeric transition, β ⁻: beta-minus, EC: electron capture.