Scintigraphy

Scintigraphy is a modern method of radionuclide imaging of internal organs, which is distinguished by its informativeness and reliability of the results obtained. The scintigraphic examination is non-invasive and atraumatic. The essence of the study: a radiopharmaceutical (RP) is introduced into the human body, then tissues and organs are visualized in images that allow determining the state of organs, identifying pathological changes and anatomical and topographic features.

Historical background

Gyorgy de Hevesy is the founder of scintigraphy, he received the Nobel Prize for this his greatest discovery. In the mid-90s, radionuclides began to be used in medicine. Various methods have appeared to determine the presence of a radiotracer in the organs, and it has become real to monitor its movement and distribution. Scanning, radiographic control and radiometry began to be widely used.

A completely new stage in medicine was the development of a scintillation gamma camera; decades later, this examination method began to be called scintigraphy. In many medical textbooks, there are other names for the technique, for example, gamma scintigraphy.

Features of the scintigraphic study

Scintigraphic diagnostics is carried out to find hidden pathologies in the body with the help of radioactive substances. A drug that is injected into the human body is called a radiotracer or radiopharmaceutical. It consists of 2 main parts: a marker (isotope) and a vector molecule. The organ or tissue under study “absorbs” the vector (special particle). The label performs an important function – it produces gamma rays, which are recorded by the gamma camera.

Gamma cameras are stationary and mobile. Each of the chambers consists of: a detector, replaceable lead collimators, photomultipliers and a computer, on the monitor of which images of the distribution of a special drug in the study area appear. Pictures obtained during the examination are called scintigrams.

Increased or decreased accumulation of the radiopharmaceutical in a particular organ or tissue can be seen in the image. An increased amount of the drug will be indicated by “hot” foci on the scintigram, and “cold foci” indicate a reduced accumulation of the drug. The radiopharmaceutical does not have a negative toxic effect on the patient’s well-being, since a small dose of the drug is administered.

The popularity of scintigraphy

Scintigraphic studies are widespread in America and European countries. More than 2007 million radionuclide studies were conducted in the United States in 17. More than 15 million patients have successfully undergone scintigraphic diagnostics and have been able to recover from serious diseases. In European countries for the same period (2007), experts conducted more than 12 million studies.

Today in America more than 13 thousand gamma cameras are working properly. In the Russian Federation, scintigraphy is not as popular as in other countries. Only 200 gamma cameras were installed. In one year, about 1 million patients are sent for diagnosis.

Indications for the procedure

Radionuclide examination is prescribed for patients who have congenital or acquired pathologies, chronic diseases. It is also advisable to carry out the procedure to clarify the degree of damage to internal organs, the activity of pathological foci. Often, scintigraphy is performed to evaluate the effectiveness of the therapy.

With the help of gamma scintigraphy, the following are examined:

• lungs;
• lymphatic system;
• spinal cord and brain;
• digestive system;
• organs of excretory system;
• a heart;
• vessels;
• skeletal system..

With the help of the procedure, diseases can be detected: myocardial contractions, pulmonary embolism, inflammatory and infectious processes, tumors, Alzheimer’s and Parkinson’s diseases. On a scintigram, a specialist will be able to see hidden diseases and changes in the thyroid gland, kidneys, liver and other vital organs.

How to prepare for a diagnosis?

Features of the preparation depend on what kind of scintigraphy will be performed. To study the thyroid gland, skeleton, heart and lungs, you need to carefully prepare. The doctor often cancels medications that can adversely affect the final results of the diagnosis. It is necessary to temporarily cancel medications that accumulate and remain in tissues and organs.

When examining the thyroid gland, it is not recommended to drink medicines containing iodine a month before the manipulation. You can eat any food during the examination of the heart, lungs, skeleton and thyroid gland. During scintigraphy, the patient should not feel hungry or thirsty, so it is advisable to eat something before starting the procedure. For the results of the heart study to be reliable, you need to empty the gallbladder (the patient must eat a few cubes of chocolate before starting the procedure). But the organs of the gastrointestinal tract are examined exclusively on an empty stomach. You can not eat food 8-12 hours before the manipulation.

Stages of scintigraphy

A radiotracer is introduced into the patient’s body, with the blood flow it enters the organs. When the substance is completely distributed throughout the organs, pictures will be taken that are recorded and processed by the computer. Images can be: dynamic, static, synchronized and tomographic. Based on the pictures, the specialist studies the anatomical location, parameters, shape and other features of the area under study.

The dosage of the drug directly depends on the examined internal organ or system. For a detailed and informative diagnosis of the heart, skeleton and brain, a large dosage of radiopharmaceuticals is required. Even a large amount of a radioactive substance does not adversely affect the health of the patient, because the radiopharmaceutical constantly decomposes and is quickly excreted from the body.

The duration of the procedure can vary from 15-20 minutes to 2,5-3 hours. The examination of the skeleton takes the greatest amount of time – 2,5-3 hours. You can examine the heart for 50-60 minutes. It will take at least half an hour to diagnose the kidneys, liver and biliary tract. The thyroid gland can be examined in 20-40 minutes. The duration of the manipulation depends on how quickly the radiopharmaceutical accumulates in the examined organ or system.

The main advantage of the technique is its information content and a small dose of radiation. During manipulation, the patient receives less radiation than with x-rays. Allergy to drugs is very rare. To make sure that the patient does not have an allergic reaction to the radiopharmaceutical, an allergy test is done.

Deciphering the results takes from 15 to 30 minutes. The specialist describes the condition of the organs, the pathologies found and writes his conclusion. Next, the patient is sent to the attending physician, who will make an accurate diagnosis and prescribe a course of treatment.

Contraindications and adverse reactions

Scintigraphy is contraindicated in patients with allergies to radioactive substances and pregnant women. If a woman is breastfeeding a baby, it is necessary to stop feeding for at least 24 hours so that the medication is excreted from the body.

Side effects after the procedure include: allergies, increased or decreased blood pressure, frequent urination. At the first occurrence of symptoms, you should inform your doctor about this and undergo a course of symptomatic treatment.