THE VALUE OF the measurement of uptake of radioactive iodine by the thyroid gland has been established beyond doubt in the diagnosis of thyrotoxicosis. However, scanning of the thyroid gland has not been considered equally important. When there is a bilateral symmetrical enlargement of the thyroid gland, as is usual in Grave's disease, the scan helps only by providing an objective assessment of the size of the gland. In this disease, there is an autonomous excessive production of thyroid hormone. As this alteration in the function involves the entire gland, a test like thyroid uptake, which studies the overall function of the gland, is likely to be useful.
In the case of a toxic nodule, the pathophysiology is somewhat different. The autonomous process is restricted to a single or multiple small areas inside the gland.1 Although the thyroid uptake measurements provide valuable data about the overall function of the
Shahani SN, Ganatra RD, Sharma SM, Ramanath P, Bagwe BA, Desai KB, Antia FP. Thyroid Scanning in Diagnosis of Toxic Nodular Goiter. Arch Surg. 1968;96(5):798-803. doi:10.1001/archsurg.1968.01330230106014