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Molecular imaging & therapy

Haumanu hangarau rāpoi ngota

Molecular imaging and therapy is a branch of radiology. It uses small amounts of radioactive materials (called radiopharmaceuticals) to diagnose or treat certain diseases or conditions.

Molecular imaging & therapy used to be called nuclear medicine.

Molecular imaging

Molecular imaging provides medical images (pictures) of your body using small amounts of radioactive materials that are injected, swallowed or inhaled.

The radioactive material travels through your body to the area being examined. The radioactive material gives off a type of radiation called gamma rays.

A special camera called a gamma camera picks up the radiation and uses it to produce images of your body.

A scan can take from a few minutes to several hours, depending on the type of scan. The scans are painless.

The radioactive material breaks down and leaves your body quickly so your exposure to radiation is kept as low as possible. Most molecular imaging scans use no more radiation than an X-ray. Allergic reactions to the radioactive material are very rare.

Radionuclide therapy

Radionuclide therapy uses radioactive material to treat certain diseases or conditions. The type and amount of radiation you receive depends on the treatment you are having.

Radioactive iodine therapy is commonly used to treat thyroid cancer and an overactive thyroid (called hyperthyroidism or thyrotoxicosis).

After surgery for thyroid cancer there may be some thyroid tissue left that the surgeon could not remove. Radioactive iodine therapy aims to remove the remaining thyroid tissue. For more information, see Radioiodine for thyroid cancer.

To treat an overactive thyroid, Radionuclide therapy aims to reduce the amount of overactive thyroid cells. For more information, see Radioiodine treatment for thyrotoxicosis (overactive thyroid).

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Written by HealthInfo clinical advisers. Last reviewed November 2022. Last updated November 2023.


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