Iodine-123
| General | |
|---|---|
| Symbol | 123I |
| Names | iodine-123, radioiodine |
| Protons (Z) | 53 |
| Neutrons (N) | 70 |
| Nuclide data | |
| Natural abundance | 0 |
| Half-life (t1/2) | 13.223 hours |
| Isotope mass | 122.905590 Da |
| Parent isotopes | 123Xe |
| Decay products | 123Te |
| Decay modes | |
| Decay mode | Decay energy (MeV) |
| electron capture | 1.228 MeV |
| 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 13.223 hours; 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.