General | |
---|---|
Symbol | 123I |
Names | iodine-123, 123I, I-123, radioiodine |
Protons (Z) | 53 |
Neutrons (N) | 70 |
Nuclide data | |
Natural abundance | 0 |
Half-life (t1/2) | 13.2232(15) h[1] |
Isotope mass | 122.9055898(40)[2] Da |
Parent isotopes | 123Xe |
Decay products | 123Te |
Decay modes | |
Decay mode | Decay energy (MeV) |
electron capture | 0.159 (159 keV) |
Isotopes of iodine Complete table of nuclides |
Iodine-123 (123I) is a radioactive isotope of iodine used in nuclear medicine imaging, including single-photon emission computed tomography (SPECT) or SPECT/CT exams. The isotope's half-life is 13.2232 hours;[1] the decay by electron capture to tellurium-123 emits gamma radiation with a predominant energy of 159 keV (this is the gamma primarily used for imaging). In medical applications, the radiation is detected by a gamma camera. The isotope is typically applied as iodide-123, the anionic form.