Analysis of techniques for the determination of thyroid function with radioiodine.

INTRODUCTION THE advent of radioiodine has increased greatly the quantitative information which may be obtained concerning the physiology of the thyroid gland. In addition to supplanting the techniques for measuring the equilibrium constants of the gland, such as the percentage utilization of the daily intake of iodide, radioiodine allows the dynamic measurement of characteristics such as the rate of accumulation of iodide by the gland and the rate of release of hormone. These measurements would be virtually impossible to obtain by other techniques and they are playing an increasingly important role in the study of thyroid physiology. The dynamic measurements of thyroid function form the major topic of discussion of this paper. In general, a radioiodine test includes the administration of radioiodine (usually in the form of iodide), measurement of radioiodine content of the thyroid by means of external detection, measurement of radioiodine content of serum and urine, and mathematical analysis of the data....