What is a Thyroid Scan?

Frequently Asked Questions:

What is Thyroid Scan used for?

The thyroid scan is a useful diagnostic tool for doctors in detecting issues with the thyroid gland. It helps ascertain if the gland is working properly or is overactive (hyperthyroidism). Doctors also use the scan to diagnose:

• carcinoma (including its spread beyond the gland itself), 
• other abnormalities like lumps (nodules), and 
• changes in the gland due to medication, surgery, chemotherapy or radiotherapy.

Understanding the test results of Thyroid Scan Test

A radiologist or other doctor specially trained in nuclear medicine provides a report. 

A normal thyroid sans abnormality in shape, size, and location of the thyroid gland has an evenly green colour on the image. An enlarged or out of position thyroid may indicate a tumour. Red spots on the image refer to abnormal growths in the thyroid.  

Why do I need a Thyroid Scan?

The thyroid is a gland located in the neck, extending from the front to the middle. 

It produces chemicals known as hormones and releases them into our bloodstream. Thyroid hormones affect the metabolic rate and levels of certain minerals in our blood. 

A thyroid scan is needed when physical examination and laboratory tests show abnormalities in the thyroid.

What happens during a Thyroid Scan?

The radiologist/technician administers a radionuclide that concentrates in the thyroid gland. An imaging camera in close proximity but without touching the head of the patient takes several images, each consuming about 5 minutes, with a slight camera shift for each image. During the test, the patient lies in bed, absolutely still, without even any swallowing to prevent any blurring of images.

What can I expect from a Thyroid Scan?

Apart from information about size, shape, and location, a thyroid scan reveals which parts of the gland are functioning properly. It indicates the thyroid gland's over-activeness (hyperthyroidism) or under-activeness (hypothyroidism). 

The scan also helps distinguish between benign and malignant thyroid nodules. This information allows doctors as the thyroid hormones impact many different body functions.

How do I prepare for a Thyroid Scan?

Do not consume food and drinks 4 hours before and 2 hours after the Thyroid Scan. The doctor may advise you to stop medications and supplements containing iodine, vitamin, kelp, minerals, tincture of iodine, and Betadine before the scan. You may seek medical advice on thyroid medication. 

You must inform the physician/radiologist about X-rays, CT scans, surgeries, etc., that you may have undergone in the past. It is advisable to avoid a Thyroid Scan if you are pregnant.

How long does a Thyroid Uptake Scan take?

After administering the radionuclide, thyroid uptake begins several hours to 24 hours later. Usually, the radiologist obtains two separate uptake measurements at different times — at four to six hours and 24 hours. 

Sometimes the technician may require a patient to wait a while if they need additional images for better visualisation or assessment of structures.  

Is thyroid scan painful?

Thyroid scan and thyroid uptake procedures are painless. It is, however, uncomfortable to keep lying down, head extended backwards, and remain still without even swallowing while the process is ongoing. 

You may feel a pin-prick upon intravenous needle injection and cold sensation up the arm as the radiotracer passes. The procedure is otherwise free of side effects and pain.

Book an appointment here for any queries regarding thyroid scan and Get a free second opinion from our experts at Yashoda Hospitals today.