Which organs can be represented?
Scintigraphy is most commonly used to examine the thyroid, kidneys, heart, lungs and bones. In principle, it can also be used to assess the function of almost all other organs, such as the liver, lymph, brain, parathyroid glands, spleen, stomach or esophagus. It is also used to go in search of inflammatory foci in case of unclear fever.
Scintigraphy of the thyroid gland
The Scintigraphy is very well suited to distinguish functioning and non-functioning thyroid tissue (disorders of thyroid function) and also to examine the shape, size and position of the organ. If the injected pertechneae accumulates more and more, it speaks for benign tumors (adenomas) that produce thyroid hormones without being involved in the control loop (thyroid autonomy). A memory defect indicates (malignant) tumors or cysts.
In addition, if there is a suspicion of autonomy, suppression scintigraphy may be performed, in which thyroid hormones are given in the form of tablets and their effects on the thyroid are checked. The normal response would be a reduction in hormone release and thus decreased accumulation of the radiopharmaceutical.
Scintigraphy of the kidneys
Static kidney scintigraphy (isotope nephrography) is rarely used, usually when there are structural changes such as malformations that can not be determined with other imaging techniques. Renal perfusion scintigraphy is more commonly used: kidney perfusion scintigraphy can be used to determine the blood flow to the kidneys, while kidney excretion scintigraphy can be used to detect urinary and ureteral drainage disorders.
With a special measuring device, the changes in the radiation activity over time and the (side-separated) kidney function can be determined. Radiopharmaceuticals are various technetium-labeled molecules that are specifically filtered out of the blood and excreted exclusively through the kidneys.
Scintigraphy on the heart
Myocardial perfusion scintigraphy is used in cases of suspected circulatory disorder (coronary heart disease). The carrier substance is thallium, which, like potassium, is transported into the myocardium, depending on the blood flow and metabolic activity. Lack of accumulation suggests vasoconstriction or occlusion or dead tissue. The pictures are taken at rest and during exercise (eg on a stationary bike).
Cardiac scintigraphy (radionuclide ventriculography) assesses the functions of the left ventricle, such as contraction force, ejection efficiency, and filling and deflation rates. The carrier for the technetium are red blood cells, whose path is recorded by the bloodstream and the heart. At the same time, the electrical cardiac activities are recorded by ECG. However, today this examination is largely replaced by ultrasound or magnetic resonance tomography.
Scintigraphy of the lungs
Pulmonary scintigraphy is usually the method of choice when there is a suspicion of vascular occlusion within the pulmonary circulation (pulmonary embolism). In lung perfusion scintigraphy, the patient is injected with small, technetium-labeled human albumin (albumin), which spreads to the smallest pulmonary vessels and gets stuck there.
Non-perfused lung sections show up as recesses (perfusion failures). In addition, lung ventilation scintigraphy must be performed to delineate perfusion failures due to embolism of recession gaps due to pulmonary disease with poor lung ventilation (eg collapse of a lung, hyperinflation of the bronchi). The patient must inhale radioactively labeled xenon gas (functional ventilation scintigraphy) or technetium-containing microparticles (static ventilation scintigraphy) for several minutes. Its distribution allows conclusions to be drawn about lung ventilation.
Scintigraphy of the bones
Skeletal scintigraphy is useful in assessing many remodeling and bone diseases. It is often used to detect metastases in cancer and to control its therapy. Most radiolabeled diphosphonate is injected, which is incorporated into the bone. Increased storage as a sign of increased metabolic activities can occur, for example, after a bone fracture, an inflammation, a tumor or a disease of wear. Decreased storage is found in the destruction of bone tissue, for example, in a cancer.