Reevaluation of the Thyroid Scan for the Assessment of Pathophysaologic Status of Thyroid Disease

갑상선 질환의 병태생리를 이해하는 데 있어서 갑상선 스캔의 재평가

To diagnosis and understand the pathophysiologic status of thyroid disease, not only hormonal measurments but also thyroid scan is believed to have a unique role. Especially in the cases of the change of the thyroid function by thyroiditis, it is emphasized that thyroid scan can be helpful in differential diagnosis. Discordant results of thyroid hormone levels and thyroid scan are found in transient hyperthyroidism, or in transient hypothyroidism. We analysed and reevaluated thyroid scan to look at the importance of thyroid scan. The results are summerised as folows: 1) 80% of hyperthyroid patients had hyperthyroidism increased RAIU with even density. they are compatible with Graves' disease. 2) 2.1% of hyperthyroid patients had normal or decreased RAIU, which are classfied as high iodine turn over genuine hyperthyroidism. 3) 8.5% of hyperthyroid patients had markedly decreased RAIU at both 2 hour and 24 hour, whose patholgic processes are suggested to be heterogenous namely subacute thyroiditis, postpartum thyroiditis, Hashimoto's thyroiditis, and painless thyroiditis. 4) 45% of hypothyroid patients had increased 24hr RAIU, 30% of hypothyroid patients were normal, 25%, decreased. In conclusion, thyroid scan should be reevaluated its useful role to asses the pathophysiologic status of thyroid disease. Especially in cases of transient thyrotoxicosis, thyroid scan is essential to diagnose and follow up the disease process.