Thyroid isotope scanning is a method of examining the thyroid gland by imaging the distribution of radioactive iodine 131 in the body at different concentrations. Thyroid nuclear scanning is a test that evaluates the absorption of iodine into normal thyroid tissue and abnormal thyroid tissue after oral administration of iodine 131. Radioactive iodine 131 creates a difference in the concentration of radioactivity inside and outside the organ and between the diseased area and normal tissue. The distribution map of radionuclides entering the body is displayed and photographed by a visualization instrument to determine the disease. This test can evaluate structural changes in hyperthyroidism, hypothyroidism, simple goiter, thyroid nodules, thyroid adenomas, thyroid cystic adenomas, and thyroid cancer. However, this test is radioactive and is not recommended during pregnancy or breastfeeding. It is recommended to avoid contact with pregnant women, nursing mothers and infants for a short period of time after the nuclear thyroid scan. The test can be performed under the supervision of a doctor.