Scintigraphy is a test based on gamma radiation. It is one of the techniques for imaging organs and also evaluating their function. The test uses radioactive isotopes, which are administered to the patient before the examination.
The apparatus used for the test, called a scintigraph, has a radiation detector. The isotopes administered to the patient send out radiation, which is recorded by the detectors and then converted into an image. Scintigraphs are outdated devices, so they are only used when examining small organs.
Newer devices, called gamma cameras, have heads that are able to cover entire organs, even larger ones.
The most commonly used isotope in scintigraphy is technetium-99m. In addition, less commonly used are iodine-131, thallium-201, and gallium-67. These isotopes are associated with corresponding chemical compounds that accumulate in the organs that are being examined.
Scintigraphy allows not only the imaging of a given organ, but above all the assessment of its function, i.e. the blood flow through the organ, bile flow in the liver or urine filtration in the kidneys.
Therefore, this examination is often more useful than X-ray examinations, which only visualize the appearance of an organ.
Preparation for the examination – scintigraphy
- The examination does not require any special preparation.
- In case of biliary, gastric and duodenal reflux the patient should be fasting. 3.
- Young children should be sedated.
- The doctor should be informed about hemorrhagic diathesis, pregnancy and any sudden problems that occur during the examination.
Procedure of the examination – scintigraphy
Before the examination, the patient is given an isotope tracer. It is most often given intravenously through a catheter, or venflon. Sometimes it is also given orally or by inhalation. The administration of the tracer is painless; sometimes there may be a burning sensation at the injection site. If there is pain, it means the vein has broken.
A tracer is given orally for a thyroid test. It is a colorless, tasteless liquid.
The timing of the tracer administration varies depending on the organ being tested. For a liver test the tracer is given 10 minutes earlier, for a bone and kidney test 3-4 hours earlier.
The examination is performed in a lying position (usually), standing or sitting. There is no need to undress. You only need to remove large metal objects from your pockets, such as keys, coins and large pendants. The head of the scintigraph or gamma camera may be stationary, or it may move in a circular motion around the perimeter of the body or in a menagerie motion.
The test takes from 5 to 90 minutes, depending on the type of test. The result is ready immediately after the test. After the test you should drink 0.5-1 liter of neutral fluids, such as water or juices.
Indications for scintigraphy examination
- Cardiovascular system and heart:
- atypical forms of myocardial infarction
- coronary artery disease
- assessment of blood flow and leakage between the ventricles and atria of the heart.
- chronic hepatitis
- drug and alcohol related liver damage. 3.
- bile ducts:
- bile outflow disorder
- gastro-duodenal reflux.
- renal artery stenosis
- kidney and adrenal tumours
- congenital malformations of the kidney
- central nervous system (CNS):
- suspected carotid artery stenosis
- CNS ischaemic attacks
- brain tumours
- herpes encephalitis
- cerebrospinal fluid circulation disorders.
- bones and joints:
- evaluation of healing of bone grafts
- suspicion of neoplastic metastases to bone
- diagnosis of rheumatoid and psoriatic arthritis.
- nodular goiter
- malformations of the thyroid gland
- Castle goitre.
- in addition to the above examinations also perform:
- salivary gland scintigraphy in case of suspicion of salivary gland tumors
- nipple scintigraphy in order to differentiate between benign and malignant lesions
- gastrointestinal scintigraphy in case of bleeding
- scintigraphy of Meckel’s diverticulum in case of bleeding, especially in children.
Scintigraphic examinations are safe. There are no complications. They can be performed at any age. They should not be performed only in pregnant women.