Thyroid disorders require precise diagnosis and targeted treatment to achieve effective and lasting results. Nuclear medicine plays a fundamental role in this area through specialized imaging and therapeutic techniques to evaluate thyroid function and deliver focused treatment. Here’s more information on how nuclear imaging is applied in treating thyroid disorders:
Exploring Nuclear Medicine
Nuclear medicine plays a fundamental role in evaluating thyroid function. Unlike other imaging techniques that only show the size or shape of an organ, nuclear imaging techniques reveal the biological processes occurring within the tissue. This functional view enables doctors to identify areas of the thyroid that are overactive, underactive, or nonfunctional.
The process involves introducing a radiotracer into the body, either by swallowing a pill or by injection. The thyroid gland naturally absorbs iodine from the blood to produce hormones, and it readily absorbs radioactive iodine tracers. Once the tracer is absorbed, a special camera takes images that show where the iodine has gone.
Diagnosing Thyroid Disorders
There are specific nuclear medicine tests designed to evaluate thyroid function. The most common procedures are the thyroid uptake scan and the thyroid scan, which are often performed together. These tests provide complementary information that gives a complete picture of thyroid function and structure.
A radioactive iodine uptake (RAIU) test measures how much radioactive iodine the thyroid absorbs over a specific period. The patient will swallow a small dose of radioactive iodine, and a probe will measure the radioactivity in the patient’s neck after several hours. A high uptake usually suggests hyperthyroidism, while a low uptake might indicate thyroiditis or a failing gland.
A thyroid scan uses a similar process but focuses on imaging the gland’s appearance. The camera captures the distribution of the radiotracer, revealing the size, shape, and position of the thyroid. This scan helps determine whether nodules are functioning or non-functioning, which is key to assessing cancer risk.
Treating Thyroid Disorders
Beyond diagnosis, nuclear medicine is also used for treating certain thyroid conditions. Radioactive iodine therapy (RAI) is a treatment for hyperthyroidism and thyroid cancer and works by targeting thyroid cells, which are the primary cells in the body that absorb iodine. In this treatment, a patient swallows a capsule or liquid containing a higher dose of radioactive iodine than that used in scans. The radioactive iodine travels through the bloodstream and is absorbed by the overactive thyroid cells or cancer cells. Radiation destroys these cells, thereby shrinking the gland or eliminating the cancer without harming the rest of the body.
Monitoring Safety
Safety is a key priority when undergoing nuclear medicine procedures. Although the term “radioactive” can sound scary, the amount of radiation used in diagnostic scans is very low and comparable to routine X-rays. After treatment, patients need to follow specific precautions to protect others from radiation exposure. Your medical team will provide a clear list of instructions to follow during this period, which may include the following:
- Hydration: Drinking sufficient water helps flush radioactive material from the body through urine.
- Hygiene: Good hygiene, such as flushing the toilet twice and washing hands frequently, reduces the risk of exposing others.
- Monitoring: Follow-up blood tests help assess hormone levels and confirm that the treatment is working as intended.
- Medication adjustments: You may need to start taking thyroid hormone replacement pills if the treatment successfully reduces thyroid function.
Following these guidelines and maintaining open communication with healthcare providers helps individuals minimize potential risks.
Schedule Your Nuclear Medicine Appointment
Nuclear medicine provides key insights and effective treatments for thyroid disorders. Understanding the function of the thyroid through advanced imaging and targeted therapy helps doctors provide precise care. If you have concerns about your thyroid health, contact a qualified neuroradiologist near you to schedule your appointment and determine if nuclear medicine is right for you.

