Source:http://linkedlifedata.com/resource/umls/id/C0203778
NCI: A type of nuclear test of the thyroid that measures how much radioactive iodine is taken up by the thyroid gland in a given time period. This test is performed to evaluate thyroid function, particularly when blood tests of thyroid function (for example, T3 or T4 levels) have abnormal results. (from Medline Plus Medical Encyclopedia)