Iodine-123

<p>Iodine-123 (123I) is a <a href="/facts/Radioactive_decay/Ya6FVjt4">radioactive</a> <a href="/facts/Isotope/KD9B1y6o">isotope</a> of <a href="/facts/Iodine/JlfMecMf">iodine</a> used in <a href="/facts/Nuclear_medicine/L9Dzjd90">nuclear medicine</a> imaging, including <a href="/facts/Single-photon_emission_computed_tomography/ag6of05C">single-photon emission computed tomography</a> (SPECT) or SPECT/CT exams.  The isotope's <a href="/facts/Half-life/kGVH8BAB">half-life</a> is 13.2232 hours; the decay by <a href="/facts/Electron_capture/EIccoV1u">electron capture</a> to tellurium-123 emits <a href="/facts/Gamma_radiation/5Drf913J">gamma radiation</a> with a predominant energy of 159 <a href="/facts/KeV/YMT1fqX9">keV</a> (this is the gamma primarily used for imaging). In medical applications, the radiation is detected by a <a href="/facts/Gamma_camera/coGxuajk">gamma camera</a>. The isotope is typically applied as <a href="/facts/Iodide/JyVRGWMX">iodide</a>-123, the <a href="/facts/Anion/wrbwhF3z">anionic</a> form.
</p>

Iodine-123 open-in-new

Iodine-123