Scintigraphy is a diagnostic method that uses radioactive isotopes for imaging and examining the condition of internal organs. Examination by means of scintigraphy belongs to the field of nuclear medicine. In this type of diagnostics, small amounts of isotopes emitting gamma radiation, i.e. so-called radiotracers, are used.
Scintigraphy is a medical procedure that produces images (scans) of structures inside the body, including areas where cancer cells are found. Scintigraphy is used to diagnose, stage and monitor the disease. A small amount of a radioactive chemical (a radioactive nuclide) is injected into a vein or swallowed.
Different radionuclides travel through the blood to different organs. A machine with a special camera moves above the person lying on the table and detects the type of radiation emitted by radionuclides. The computer creates a picture of the areas where the radionuclide is deposited. These areas may contain cancer cells. Also called radionuclide scanning.
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Scintigraphy – indications
The indication for the scintigraphy examination is primarily the suspicion of a neoplastic disease or the occurrence of metastases in the case of an already diagnosed neoplastic disease. Scintigraphy is also used in the case of unexplained gastrointestinal bleeding, regurgitation of food contents into the esophagus, in heart muscle diseases, in chronic hepatitis and pneumonia, in suspected cerebrospinal fluid circulation and in suspected kidney disease. Scintigraphy also allows non-invasive look inside the bones and brain, thus assessing their condition and identifying possible changes in the form of tumors.
Scintigraphy allows you to assess the shape, location and condition of an organ, as well as accurately determine the flow of fluids in the circulatory system, urinary system and digestive system. This method is therefore also used to diagnose problems with the flow of blood, urine and bile. In some cases, the entire body of the patient is examined with this method – especially when cancer has metastasized to various organs and bones.
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Scintigraphy is performed as follows. The patient is given a small dose of a radioactive isotope, either intravenously or through a cannula. The patient is placed on a special table and the doctor starts a diagnostic apparatus called a scintigraphy.
You have to wait for the action of isotopes for a while – the doctor informs about the required time of accumulating the pharmaceutical in the organ – then the doctor starts scintigraphy, i.e. transferring the image of the organs, or rather the image of the radiation distribution of compounds created by combining radioactive isotopes with chemical compounds present in the body. The image is transferred by the gamma camera to the monitor screen.
The scintigraphy examination is painless and non-invasive, it is performed in a lying or sitting position. The result is in the form of the described photos. If there are changes in an organ, they will appear as dark spots (in black and white photos) or bright spots in the scintigraphy image – the affected places absorb isotopes to varying degrees and their image appears as darker or bright points.
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Bone scintigraphy (bone scan) is a specialized radiological procedure used to examine various bones in the skeleton. This is to identify areas of physical and chemical changes in the bone. Bone scintigraphy can also be used to track the treatment progress of certain medical conditions.
Bone scintigraphy is a type of nuclear radiology procedure. This means that a small amount of radioactive material is used during the procedure to aid in examining the bones. A radioactive substance called a radionuclide or tracer builds up in bone tissue where there are abnormal physical and chemical changes.
The radionuclide emits a type of radiation called gamma radiation. Gamma radiation is detected by a scanner which converts the information into an image of the bone.
Areas where radionuclide builds up are called “hot spots” and can indicate the presence of medical conditions such as arthritis, malignant bone tumors, metastatic bone cancer (cancer that has spread from elsewhere such as the lungs), infections bone, bone trauma not visible on regular x-rays, and other bone conditions.
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Bone scintigraphy – indications
Bone scintigraphy is primarily used to detect the spread of metastatic neoplasms. As cancer cells multiply rapidly, the bones will appear on the scintigraphy as previously mentioned as a “hot spot”. This is due to increased bone metabolism and bone repair in the area of cancer cells. Bone scintigraphy can also be used to assess the severity of cancer before and after treatment to assess the effectiveness of treatment.
Other reasons for performing a bone scan procedure may include, but are not limited to:
- assessment of bone trauma in situations where a simple X-ray does not reveal an injury,
- detection of fractures that are difficult to locate,
- determination of the age of fractures,
- detection and / or evaluation of bone infections (osteomyelitis),
- assessment of unexplained bone pain
- to detect conditions such as arthritis, benign bone tumors, Paget’s disease (a bone disorder usually seen in people over the age of 50, where the bones thicken and soften, and long bones become curved) and vascular necrosis of the bone tissue due to loss of blood supply blood to bone)
There may also be other reasons your doctor may recommend a bone examination.
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Kidney scintigraphy is one of the many imaging methods used to assess kidney function. Ultrasound, computed tomography (CT), and magnetic resonance imaging (MRI) can also be used. Your doctor will determine which of these tests will provide the best information about your kidneys.
Four types of kidney imaging can help you determine if your kidneys are working normally or not:
- kidney cortex scintigraphy – detects the amount of functioning renal cortex tissue on the basis of images taken with a gamma camera approximately two hours after injection of the radiopharmaceutical,
- renal perfusion and functional imaging – tests blood flow to the kidneys and identifies potential narrowing of the renal arteries. It can also investigate whether a kidney tumor is a focus of benign tissue or a space-consuming lesion such as a cyst or tumor. With a series of photos taken within 20 to 30 minutes immediately after an injection of the radiopharmaceutical, it also helps determine how well your kidneys are working.
- kidney diuretic scintigraphy – detects kidney obstruction or urinary flow obstruction based on pictures taken before and after the injection of a diuretic, which is used to move urine through the kidneys,
- kidney scintigraphy with an ACE inhibitor – helps to find out if the cause of high blood pressure is due to the kidneys, due to a narrowing of the kidney artery or arteries by comparing pictures of the kidneys before and after taking a blood pressure medicine called an ‘ACE inhibitor’.
These procedures can be valuable in identifying renal failure and / or complications associated with transplantation, as well as in detecting kidney-related injuries.
No special preparation is necessary prior to the scintigraphy examination. The exception is the scintigraphy of the organs of the digestive system, which should be presented on an empty stomach. Usually the scintigraphy takes about an hour, including administering the isotopes and waiting for them to take effect.
In the case of children who are unable to lie still during the scintigraphy examination, sedatives and even sleeping pills are administered before the scintigraphy is performed.
Before the examination, it is not necessary to undress, but all metal objects should be removed, for example, earrings, pendants, bracelets, belts with a metal buckle, a watch.
If the patient’s entire body is examined by scintigraphy (this is so if it is necessary to diagnose and accurately locate inflammatory foci appearing throughout the body), he is placed on a special movable table that allows the whole body to be filmed from different sides using a gamma camera. The images obtained on the monitor are three-dimensional.
After the scintigraphy examination, you should drink plenty of fluids to remove radioactive isotopes from the body as quickly as possible.