Possibilities of Using Tc99m in Place of Radioiodine in Thyroid Function Studies

Abstract

SummaryWith Tc99m thyroid scintigrammes with excellent resolution may be obtained which are comparable to those obtained with I131 and I125 with “standard” equipment of current use.Thyroid uptake measurements of Tc99m may be used as a rapid test of the capacity of the thyroid gland to concentrate iodide. It is not organified by the thyroid gland and for this reason cannot be used for the study of subsequent phases of glandular function.Total body dose resulting from the diagnostic use of Tc99m is 1000 times less than that from comparable amounts of I131, so that Tc99m might be particularly useful for application in children and pregnant women.