Iodine Uptake Scan

Iodine Uptake Scan is an examination of the thyroid function in which one is given a moderate amount of radioactive iodine to determine how much of it is absorbed by the thyroid gland in a given period of time.

How is the test conducted?

The person to be tested is given a capsule which contains radioactive iodine or radioiodine. After a little while period of time (generally which is 6 to 24 hours later), the patient than returns to the clinic for the measurement of radioactivity of the thyroid gland. It is completed using a certain device which is known as gamma probe.

This device is placed on the thyroid gland throughout the external part of the neck. After that, the patient normally lies down and then the scanner runs over the neck and scans the entire area. This process takes around 30 minutes.

Preparation for this test

The patient should not eat anything for 8 hours before the test is conducted. The doctor or the physician might advice the patient not to take certain drugs or medications that might interfere with this particular test.

Drugs that can increase result:

  • Barbiturates
  • Lithium
  • Estrogens
  • Thyroid stimulating hormones
  • Phenothiazines

Drugs that might decrease the result:

  • Corticotropina
  • Antihistamine
  • Antitiroideos drugs
  • Corticosteroids
  • Solution of Lugol
  • Nitrates
  • Potassium iodide saturated solution
  • Drugs for the thyroid
  • Tolbutamida

Thus, the patient must stay away from the above mentioned drugs unless the doctor advises otherwise.

The doctor must be informed if the patient has encountered any such situation:

  • Diarrhea (the absorbed radioactive iodine could fall off the body).
  • Recent radiological procedures in which means of resistance with iodine have been used (in the previous two weeks).
  • Very little or too much iodine in the diet.