Disparate thyroid imaging. Combined studies with sodium pertechnetate Tc 99m and radioactive iodine

A dissociation between thyroid concentrating and organification, measured respectively by sodium pertechnetate Tc 99m imaging and the 24-hour radioactive iodine scan, was found in seven of 204 patients examined by combined isotope studies. Histologic diagnoses of adenomatous goiter, follicular adenoma, or thyroid carcinoma (mixed papillary and follicular) indicated that no unique morphologic correlates could be predicted in patients with discordant images. The combined use of sodium pertechnetate Tc 99m and radioactive iodine studies were found to be a useful tool for obtaining serial characterization of functional change following thyroid injury in a patient with de Quervain thyroiditis. (JAMA228:866-869, 1974)