[Evaluation of thyroid diseases in nuclear medicine]

The thyroid is one of the larger endocrine glands in the body. The thyroid size is 15-20 gr. The gland produces hormones that regulate all metabolic processes in large number of tissues in the body, and produces hormones that affect the growth and rate of function of many other systems in the body. Studies of the endocrine system are among the original procedures in nuclear medicine. Thyroid scintigraphy and radio-tracer uptake studies remain an important part of the practice of nuclear medicine. Scintigraphy reveals functional and anatomic status of thyroid gland. A systematic and complete interpretation of the thyroid scintigrams requires assessments of thyroid size and configuration and identification and description of focal abnormalities, including hot and cold nodules and extrathyroidal activity in the neck or mediastinum. Early diagnosis and treatment of thyroid disease have made possible the reduction of morbidity and mortality associated with these disorders.