What are normal thyroid scan and iodine uptake results?
Thyroid images are obtained 24 hours after the administration of 123 I or approximately 30 minutes after 99m Tc pertechnetate. The gland should appear uniform throughout with smooth contours. The isthmus and pyramidal lobes can be observed, although they are more commonly seen in patients with Graves’ disease. Iodine uptake values are usually obtained at 2 and 24 hours after administration of the 123 I pill. The 2-hour uptake typically should be 2% to 10%, and the 24-hour uptake is usually 10% to 30%. These values may differ slightly, depending on the radiotracer that is used, so it is always important to know what a particular institution considers as the normal range of uptake.