Introduction of Thyroid Scan
Table of Contents
A thyroid scan or thyroid scintigraphy is a diagnostic nuclear medicine assay that provides information regarding the structure and function of the thyroid gland and this technique makes it able to see the size, shape, function, and position of the gland. A capsule or liquid containing a radiopharmaceutical called
Iodine-123 (a radioactive isotope of iodine) has a tiny amount of radioactive molecules in it. A gamma camera is applied to take photos of the thyroid after the radiopharmaceutical has been ingested.
Procedure of Thyroid Scintigraphy
A thyroid scan completes in three steps-
- Ingestion of the radiopharmaceutical: A nuclear medicine technologist will explain what will happen during the study and he/she will provide to swallow a capsule or liquid containing the radiopharmaceutical.
- A waiting period: After completion of the administration of the radiopharmaceutical, the patient is free to leave the department. The radio technologist will give an exact time to return for the actual imaging and normally, imaging takes place between four and 24 hours after radiopharmaceutical administration.
- Thyroid scan: Prior to imaging, the patient will be asked to void (use the bathroom) and then the camera comes very close to the neck. Three images of the thyroid gland are taken, each approximately 12 to 20 minutes in length. It is very important that the patient remains as still as possible during imaging to obtain the best quality images.
Uses of Thyroid Scan or Thyroid Scintigraphy
Thyroid scintigraphy can help assess-
- Neck masses
- Ectopic thyroid
- Thyroglossal duct cyst
- Thyroid malignancy
- Benign diffuse goiter
- Radiation therapy planning
Keynotes on Thyroid Scan or Thyroid Scintigraphy
- Anything to eat or drink an hour prior to administration of the radiopharmaceutical and for 30 minutes afterward is strictly prohibited.
- Even though the camera may appear large and intimidating, it does not touch the patient.
- This type of scanning loads the smallest radiation dose needed to obtain the desired result.
- The nuclear medicine physician is responsible to provide a report.