The major indications for thyroidimaging with sodium iodide (123I) are for evaluation of thyroidfunction (uptake) and/or morphology (imaging). Thepatient fasts before receiving the oral dose of 0.1 to 0.4 mCi(3.7–14.8 MBq) of sodium iodide (123I) typically in an encapsulateddosage form. Images are obtained of the thyroidand surrounding area 4 to 6 hours after ingestion.
