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Scintigraphy is a type of diagnostic imaging test. It allows you to visualize the condition of various internal organs, both their morphology and physiology. It consists in the administration of small doses of substances labeled with radioactive isotopes that emit gamma rays recorded by a scintigraph or gamma camera. Radioisotopes decay in a short time, and the image of an organ is created on the basis of the registration of their distribution and decay. The most frequently used marker substances are various elements that accumulate in specific organs, e.g. iodine in the case of the thyroid gland.
What is heart and blood vessel scintigraphy?
Substances used for heart scintigraphy the most common are thallium chloride or MIBI (2m technetium labeled 99-methoxy-isobutyl isonitrile). Heart scintigraphy is a high sensitivity test. There are different types of test depending on what parameters need to be visualized. Individual types scintigraphy they have their own complicated names, but each of them is based on the imaging of the morphology and work of the heart and blood vessels within it, and they differ mainly in the type of the administered agent and the method of its administration, which allows for the visualization of various anatomical details and physiological functions. Radioizotop makes it possible to visualize e.g. the first pass of blood through the heart muscle. This allows you to assess the ventricular ejection volume and determine the tightness of the heart walls and blood vessels within it. If there are leaks in the walls of the heart and large blood vessels, visualize the flow radioisotope allows you to clearly see where the leak is. The flow of the marker through the heart shows its structure and efficiency, on the basis of which it is possible to calculate various parameters describing the work of the heart. The examination also enables the assessment of tracer accumulation, e.g. in the left ventricle. Amount of accumulated radioisotope it is proportional to blood flow, and in the event of ischemia, areas where the isotope does not accumulate will be observed. In this way, ischemic areas, their location and size can be pinpointed.
The test can be performed at rest, during an exercise test, or after administration of coronary vasodilators. Imaging of the coronary vessels allows you to detect their dangerous narrowing. In the so-called angiosintigraphy the emphasis is precisely on imaging the blood flow and vasoconstriction after intravenous administration of the imaging agent. Another type of scintigraphy contrast may be administered, which accumulates in necrotic tissues and illustrates the focus of a heart attack.
What are the indications for a cardiac scintigraphy?
Heart scintigraphy is a test performed primarily in people with suspected coronary heart disease. It also allows to assess the post-infarction status of this organ. It is also a diagnostic test for suspected pulmonary embolism. Scintigraphy Moreover, it enables the diagnosis of many different diseases of the heart and blood vessels (e.g. cardiomyopathy, thrombophlebitis), it is also often performed to enable the patient’s qualification for procedures (e.g. coronary aortic bypass) and to assess the condition after performing it type of treatments. An indication it is also monitoring the work of the heart with an implanted pacemaker.
How to prepare for the test and what is its course?
Before making an appointment, inform your doctor about any diseases – especially those related to the blood coagulation system – and about any medications you are taking. It may be necessary to have a blood test for creatinine levels in advance to check that the kidneys are working properly, which is important for the proper expulsion of the marker agent from the body.
Heart scintigraphy is a test that is not very troublesome for the patient. On the day of the examination usually fasting is required and no special preparation is required. The study itself it is most often associated with the inconvenience of injection and insertion of a cannula through which a contrast agent is administered intravenously (less often orally). Before the examination remove all objects from the body that may interfere with the formation of the image, such as a watch, jewelry, belt, remove keys, cell phone or coins from the pocket. Patient in progress survey is lying down, unless the test is performed during a stress test.
After the examination drink plenty of water to help your body clear of the radioisotope. The result is obtained in the form of images together with the description.
Possibility of complications and contraindications to the examination
Heart scintigraphy it is a relatively safe test because the administered amount of radioisotope is small and it is quickly broken down and excreted from the body. Therefore, there is even no limit to the frequency of the test or the patient’s age (it can be performed even in young children and the elderly), and complications they happen extremely rarely and result from the individual reaction of the organism.
An absolute contraindication pregnancy and breastfeeding are to be performed.