Thyroid diagnostics

Before any diagnostic tests are carried out, a detailed consultation about the symptoms and a physical examination are essential.

Thyroid hormones (T3/T4), TSH, TRH and antibodies can be measured precisely in the blood. Not all thyroid diseases can be diagnosed on the basis of blood tests, and abnormal values must always be assessed in the overall context of the other blood values measured.

Ultrasound examination is one of the most important methods for detecting thyroid disease. It is harmless for the patient and can be carried out without any strain. Ultrasound can determine the size of the thyroid gland and detect any thyroid nodules present. However, ultrasound cannot provide any information about the thyroid's hormone production, nor can it reliably distinguish between benign and malignant thyroid nodules.

In conventional thyroid scintigraphy, a radioactive substance (technetium) is injected. This substance behaves like iodine in the body and is therefore taken up by the thyroid gland (but not stored there, and excreted again in the urine after a short time). A camera (gamma camera) records the radiation from the substance while it is briefly present in the thyroid. Areas of cells with high hormone production take up more of the substance than normally functioning areas or areas that no longer produce any thyroid hormone. This produces a map of metabolic activity in the thyroid gland.

“Hot nodules” are areas with high uptake of the substance and therefore also areas with high hormone activity.

“Cold nodules” are areas in which no thyroid hormone is produced.

Scintigraphy can only show the metabolic function of the individual sections of the thyroid. It cannot indicate whether a nodule is benign or malignant.

If a malignant thyroid nodule is suspected (especially in the case of nodules that are cold on scintigraphy), an ultrasound-guided fine-needle aspiration can provide further information. However, this method cannot provide 100 % certainty in all cases as to whether the nodule is a benign thyroid nodule or a malignant thyroid tumour.