title: Thyroid uptake of radioactive iodine in hyperthyroidism.
abstract: We compared the 24-hour uptake of radioactive iodine (RAIU) in hyperthyroid patients diagnosed from 1970 to 1972 (Group A) and from 1975 to 1976 (Group B). Mean RAIU values in Group B decreased from those in Group A. In 1969 we lowered the normal range for the RAIU test to 0% to 24%, and used the new range for the diagnosis of hyperthyroidism in both groups of patients. The RAIU in Group B is within normal limits in 14% of the patients with Graves' disease and 80% of the patients with toxic nodular goiter (TNG). This study demonstrates that in our geographic area, the 24-hour RAIU has become a poor test for the diagnosis of hyperthyroidism, particularly TNG. However, the test should be performed before radioactive iodine therapy because it is necessary in calculating the therapeutic dose.
mesh_terms: D000328:Adult; D000368:Aged; D005260:Female; D006044:Goiter, Nodular / Q000378:metabolism; D006111:Graves Disease / Q000378:metabolism; D006801:Humans; D006980:Hyperthyroidism / Q000175:diagnosis / Q000378:metabolism*; D007455:Iodine / Q000378:metabolism*; D007457:Iodine Radioisotopes; D008297:Male; D008875:Middle Aged; D013960:Thyroid Function Tests
chemical_list: D007457:Iodine Radioisotopes; D007455:Iodine