The significance of thyroid iodine 131 examination

There are many medical tests that people don’t understand their specific functions, just like the significance of thyroid iodine 121 test is unknown to many people. Thyroid iodine 131 is mainly used to check the changes in radioactive counts in the human thyroid area to understand the thyroid function. This is a basis for determining whether the thyroid function is hypothyroid or hyperthyroid. Let’s learn more about it together~

1. Thyroid 131 Iodine Uptake Test

The principle of the 131I thyroid uptake test is as follows: iodine is one of the raw materials for the thyroid gland to synthesize thyroid hormones. Radioactive 131I can also be taken up and participate in the synthesis of thyroid hormones. The amount and speed of its uptake are closely related to thyroid function. By introducing 131I into the subject's body and using an in vitro detection instrument to measure the changes in the radioactive count in the thyroid area, we can understand the uptake of 131I by the thyroid gland and thus determine the function of the thyroid gland.

2. Normal value

Each hospital has its own normal reference value. Generally, the 2-hour I rate is 10%-30%, 4-hour 15%-40%, and 24-hour 25%-60%. Women have higher rates than men, and children and adolescents have higher rates than adults. Although the normal range may vary, the overall change pattern of the 24-hour thyroid uptake rate can be used to diagnose thyroid disease. In normal people, the thyroid uptake rate gradually increases over time and reaches a peak in 24 hours.

3. Clinical significance

Abnormal results: (1) Hyperthyroidism, also known as toxic diffuse goiter and Graves' disease, is an autoimmune disease. Symptoms may include intolerance to heat, excessive sweating, excitement, increased appetite, accompanied by weight loss, tachycardia, special eye signs (exophthalmos), thyroid enlargement, thyroid vascular murmurs, tremor, etc. Basal metabolic rate (BMR) measurement and thyroid radionuclide computed tomography (ECT) are of diagnostic value. (2) Hypothyroidism. It is caused by insufficient synthesis or secretion of thyroid hormone. It is divided into three types according to the age of onset, namely cretinism, juvenile and adult hypothyroidism (called myxedema when severe), and the clinical manifestations may be different.

People who need to be examined: patients with abnormal thyroid function.

IV. Precautions

Unsuitable groups: pregnant and lactating women. Note before the examination: pay attention to a normal diet, a normal work and rest schedule, and prevent endocrine disorders. Requirements during examination: Actively cooperate with the doctor's requirements.