Nuclear medicine examinations must not be performed during pregnancy. If you are breastfeeding, it may be necessary to interrupt breastfeeding for a short period.

Nuclear medicine examinations and therapies use X-rays. In contrast to radiological techniques, however, the radiation is not applied to the patient from outside (as is the case with X-rays, for example), but rather the patient is administered a radioactive substance, which can then be measured. In diagnostics, we mainly use the artificially produced radionuclide technetium-99m (Tc-99m), which has a very short half-life of around 6 hours and is generally injected intravenously. What is special about nuclear medicine is that only very small amounts of these radionuclides are required (often in the nanomolar range) to detect metabolic processes or even individual molecules in the body. In this context, the term molecular imaging is sometimes used. Due to these small quantities and the short half-life of the radionuclides, the radiation dose is usually low. Typical contrast agent side effects do not actually occur in nuclear medicine due to the very low doses used.

No contrast agents are administered in nuclear medicine. Instead, minute amounts of a radioactive substance (tracer) are used, which accumulates in certain organs and thus provides information about the function of an organ. Due to the very small amount of radionuclide required, there are no typical contrast agent side effects, as are known to occur in rare cases with CT or, even more rarely, with MRI.

The person to contact for all questions relating to the thyroid gland, who also has all the necessary technology at their disposal, is a nuclear medicine specialist. If necessary, treatment can also be carried out or initiated by the nuclear medicine specialist and then continued by the referring physician.
The healthy thyroid gland is a small, butterfly-shaped organ that lies like a shield in front of the windpipe below the larynx. Normally, it is not visible or palpable. The function of the thyroid gland is to produce and store thyroid hormones from iodine and other substances (including the amino acid tyrosine) and to release them into the bloodstream in quantities required by the body. The release of thyroid hormones into the blood is normally strictly controlled by certain areas of the brain (the pituitary gland and hypothalamus). An overactive or underactive thyroid gland can have serious effects on the body's metabolism.

Ultrasound
An ultrasound examination is used to assess and measure the appearance and size of the thyroid gland. Nodules or cysts (fluid-filled cavities) can be detected, assessed, and measured.

Thyroid scintigraphy is used to produce functional images of the thyroid gland. This technique exploits the principle that cells with high metabolic activity (e.g., hot nodules) absorb larger amounts of a radioactive substance than cells with lower activity (e.g., cold nodules). These highly active areas then release relatively more radiation than other areas. Cold nodules have a disproportionately high risk of tumor disease, while hot nodules often manifest themselves through metabolic changes.

In addition to these two imaging examination methods, the so-called thyroid values (including FT3, FT4, and TSH) are determined in the blood, and, if necessary, important antibodies such as TPO or TRAK are also determined. This procedure allows thyroid enlargement and thyroid dysfunction (hyperthyroidism and hypothyroidism) to be reliably detected and their causes identified.

After checking the size and function of your thyroid gland, the nuclear medicine specialist will, if necessary, develop an individual treatment plan for you, discuss it with you, and send it to your family doctor.