Scintigraphy in endocrinology. Radioisotope study of the thyroid gland

The development and expansion of the diagnostic capabilities of modern medicine has made it possible to leave behind many techniques that do not meet the growing requirements for the quality of imaging, the degree of safety and the amount of information received. Thyroid scintigraphy, being a pioneer among radionuclide diagnostic methods, has managed to retain its position as a highly informative examination with the potential for further development.

Emerging new and promising techniques that can provide a similar or greater amount of information, one way or another, are based on the principles of performing scintigraphy. Radionuclide diagnostics plays a significant role not only in clarifying the nature of the disease, but also in the treatment of malignant neoplasms of the thyroid gland.

The essence of the method

Thyroid scintigraphy is a radionuclide method for assessing the functional activity of the lobes of the thyroid gland (TG), based on the properties of its tissues to absorb iodine and use it to produce hormones. The use of radiopharmaceuticals (RP) in the diagnostic process - chemical compounds perceived by the tissues of the body as a necessary participant in metabolism and containing radioactive isotopes in the structure, allows you to register the intensity and uniformity of absorption, accumulation and distribution of the substance in the thyroid gland.

In the absence of alternative imaging modalities available today in diagnostic medicine, such as ultrasound, MRI or CT, scintigraphy was the only way to get an image of the internal organ. Today, using all of the above methods, you can get the most useful information about the shape, structure and location of the thyroid gland, however, none of them is able to assess its functional state.

The mechanism for obtaining information is the introduction into the body of radiopharmaceuticals (for example, radioactive iodine), which is actively absorbed or not absorbed by the endocrine organ. With the subsequent registration of the radiation intensity, it is possible to obtain a flat or three-dimensional image (in the case of an emission computed tomograph), reflecting the zones of normal, increased or decreased concentration of a radioactive substance.

Areas with increased radiation highlighted in color or hatching indicate tissue hyperactivity, and areas with reduced or absent radiation indicate their partial or complete functional insufficiency. The use of scintigraphy is advisable only to determine the activity of producing hormones of one of the parts of the thyroid gland (node or lobe), the pathological condition of which has already been identified using laboratory or instrumental methods of research.

On color images, inactive thyroid tissues are shown in blue, and active ones in red.

Important! Scintigraphy cannot be considered an independent research method, based on the results of which any diagnostic decision can be made. Its use is justified only if additional information is needed.

Choice of radiopharmaceutical

Since radionuclide diagnostics is based on the possibility of recording the intensity and amount of ionizing radiation emanating from radiopharmaceuticals, there are 3 main requirements, compliance with which makes scintigraphy the most informative and safe diagnostic method:

The behavior of the drug in the human body should be identical to the behavior of natural organic substances.
The drug must contain a radioactive nuclide or a radioactive label that allows its location to be determined using recording equipment.
The radiation dose during diagnostics should be minimal.

An important aspect when choosing radiopharmaceuticals is the half-life, the duration of which should not exceed the permissible levels of exposure, but at the same time, it would allow performing the necessary diagnostic manipulations. The use of iodine isotopes (123Ι and 131Ι) in nuclear medicine can be considered a classic, since the first studies carried out with their help were described as early as 1951.

Thanks to the ability of the thyroid gland to capture iodine, it became possible to fix the rate of its accumulation and distribution in tissues. However, to date, the use of 123Ι and 131Ι isotopes is limited by the need for a subsequent course of therapy for cancer or toxic adenoma of the thyroid gland.

Due to the fact that the half-life of the 123Ι iodine isotope is 13 hours, and the 131Ι isotope is 8 days, the latter, as the most traumatic, is used to destroy malignant cells, and the use of the 123Ι isotope for diagnostic purposes makes it possible to estimate the rate of capture of molecules and calculate optimal therapeutic dose.

Modern radiopharmaceuticals are isotopes that, as a result of decay lasting about 7 days, form a new unstable element called a radionuclide label. A feature of such a label is the ability to create symbiosis with any chemical element involved in the metabolic processes of a particular organ. The most common drug in medical practice is technetium (99mTc).

The advantages of technetium can be considered an extremely short half-life (6 hours) and the absence of the need to introduce iodine into the body, which makes it possible to obtain a “cleaner” picture from a diagnostic point of view. Another advantage of technetium, which allows minimizing the risks of the negative effects of radiation, is the possibility of obtaining it from the parent isotope stored in a container immediately before the diagnostic procedure, as well as the possibility of adjusting its optimal activity.

Container for storage and generation of technetium 99mТс

Indications and results

Radioisotope examination of the thyroid gland is carried out according to strictly defined indications. For example, a thyroid disease such as hyperthyroidism (hyperfunction) may be due to diffuse or nodular changes in the tissues of the gland. The main purpose of the examination, in this case, is to determine the magnitude of hyperfunction, which in case of diffuse goiter can be done using ultrasound and laboratory blood tests.

At the same time, ultrasound shows the size, structure and blood supply of the thyroid gland, and a blood test shows the level of hormones, which is quite enough to make a diagnosis. Scintigraphy is not required even if a small number of nodes up to 3 cm in size are detected, since regardless of the test results, an excess (hyperthyroidism) or lack of hormones (hypothyroidism) cannot be caused by such nodes.

Thus, thyroid scintigraphy should be prescribed for the following indications:

the presence of one or more nodes more than 5 cm in diameter with a simultaneous increase in hormone levels due to hyperfunction of the gland. In this case, using scintigraphy, it is possible to assess the intensity of absorption of radiopharmaceuticals by the tissues of the node and, based on the results obtained, judge the source of increased hormone production. After identifying the node that caused hyperthyroidism, the best way to remove it is selected;
the presence of a large node, occupying at least half of one lobe of the thyroid gland (adenoma). The examination is carried out in order to determine the hormonal activity of adenomatous tissue, which can fully perform the functions of a hormone-producing organ, or can be completely inactive. When determining further treatment tactics, they rely on the results of scintigraphy and the anatomical features of the location of the node (presence of compression of neighboring organs). If the node is actively growing, but does not produce hormones, it is removed;
the likelihood of thyroid tissue formation in uncharacteristic places. An atypical location of the thyroid gland is a rather rare occurrence, much more often the appearance of thyroid tissue in various places is characteristic of the spread of metastases in thyroid cancer. Scintigraphic examination helps with high accuracy to identify the localization of pathological foci in lingual, retrosternal and other locations. In the future, as a rule, therapy with iodine isotopes is carried out.

Important! When evaluating the results of scintigraphy, terms are used that reflect the degree of activity of thyroid tissues. The area or node that actively accumulates isotopes is called "hot", and the passive area is called "cold".

Scintigraphic images of pathological changes in the thyroid gland

Training

It is believed that preparation for scintigraphy includes a list of restrictions, the main purpose of which is to achieve the most reliable results. So, in order to avoid possible distortions, a month before the proposed examination, you should stop using products containing iodine (for example, seaweed), and iodine-containing medicines should be abandoned much earlier - approximately 2-3 months before the procedure.

For 2-3 weeks, it is necessary to stop taking drugs prescribed as part of hormone replacement therapy (L-thyroxine, Thyreodin, Euthyrox), as well as thyreostatics (Tyrozol, Mercazolil, Propicil). However, taking into account the specifics of diagnostic scintigraphy, which is performed to differentiate an existing diagnosis, such a long preparation is usually not necessary.

In practice, the intake of iodine-containing drugs is stopped 1-2 days before the procedure, while the doctor must know exactly the amount and dosage of drugs taken by the patient and take these data into account when reading the results. The use of technetium 99mТс as a radiopharmaceutical allows not to carry out a long preparation for the examination, since this radionuclide does not participate in iodine and hormonal metabolism, but reflects the natural processes occurring in the body.

Holding

Diagnostics includes 2 stages:

receiving radiopharmaceuticals;
scanning.

If iodine isotopes are used during the scintigraphic examination, the patient drinks the drug in the form of a liquid or in the form of a capsule. Depending on the radiopharmaceutical used, the scan may take up to 2-24 hours. When using technetium, the radionuclide is injected directly into a vein, and after a few hours the scan is started.

To perform the scan, the patient lies down on a couch located in a special room in front of the gamma camera. Modern gamma cameras register radiation coming from the patient with the help of a crystal (detector) that reacts to isotopes with flashes, which, in turn, interacting with a cathode ray tube, form an image on photographic paper.

The use of computer technologies makes it possible to carry out not only stationary images, but also serial ones, and, keeping the previous result in memory, determine the nature and speed of isotope movement. Scanning with an emission computed tomography scanner, the detector of which rotates around the couch with the patient, is extremely informative.

This approach allows you to take several frames at different angles, which, with the help of computer processing, take the form of a three-dimensional image. The most modern achievement of nuclear diagnostics can be considered a positron emission tomograph (PET). The sensitivity of this detector is so high that the examination can be done using significantly lower doses of radiopharmaceuticals or radiopharmaceuticals with a very short half-life.

PET scanning is a commonly used diagnostic method

Contraindications

It is also possible to conduct scintigraphy during breastfeeding, however, from the moment the radioactive drug is taken (introduced) until the moment of its final decay, breastfeeding should be replaced with artificial milk, and one's own milk should be expressed and poured out. In some cases, when using "hard" isotopes of iodine, close contact with the child should be minimized.

Among the side effects that occur in patients with the introduction of radiopharmaceuticals, a reaction to iodine-containing drugs is noted:

allergy;
increase in body temperature;
flushing of the face, neck or hands;
dizziness;
nausea;
change in blood pressure.

If the patient has a history of gastrointestinal diseases, antacids can be taken after taking an iodine-containing radiopharmaceutical. An adequate drinking regimen will also help minimize negative feelings after taking the radiopharmaceutical.

Important! When using technetium as a radiopharmaceutical, the likelihood of an allergic reaction is excluded.

Scintigraphy for thyroid cancer

Despite the fact that scintigraphy remains one of the main methods of differential diagnosis of thyroid diseases, in the diagnosis of cancer, the method is considered uninformative. The main reason can be considered the difference in the forms of malignant neoplasms, some of which are able to absorb radiopharmaceuticals, and some remain inactive. However, according to statistical data, the number of malignant neoplasms among the "cold" nodes is significantly greater than among the "hot" nodes.

Scintigraphy for infants is done exclusively using technetium.

Another point of support in the diagnosis of malignant neoplasms of the thyroid gland using scintigraphy can be considered a high rate of metabolic processes in the tumor tissue, and, accordingly, increased glucose consumption. Using the 18FDG radionuclide label, perceived by tissues similarly to glucose, and a positron emission tomograph, thyroid cancer can be detected with 85% accuracy.

The main criterion that determines the choice of a clinic where scintigraphy is performed can be considered the availability of the latest generation equipment, which allows not only to increase the accuracy of diagnosis, but also to significantly reduce the dose of the radiopharmaceutical used.

Thyroid scintigraphy is a diagnostic method that uses radioisotopes. This method is aimed at obtaining a two-dimensional image using radiation emitted by an organ. The study allows you to determine the functional activity of the gland, find the foci of the disease, as well as a change in the pattern created by the interweaving of blood vessels on the surface of the organ.

This method is based on the property of the thyroid gland to absorb, accumulate, and also remove iodine, even radioactive. For scintigraphic study, radioisotopes of iodine 131 and 123, technetium isotopes 99 are used. Other isotopes that are suitable for this diagnosis can be used.

Question: What is thyroid scintigraphy? Should it be carried out? Does it pose another health hazard? There are many questions, the answer to them is short - diagnostics of these on an apparatus using radioisotopes is necessary and safe. To understand this, you should carefully study the principle of operation.

The gland intensively absorbs iodine, and the intensity is much greater than in other organs. Technetium is also very well absorbed by the thyroid gland. But technetium is not used by the body to produce hormones, so it is eliminated from the body naturally rather quickly. The introduced radioisotopes of iodine and technetium are rapidly absorbed by the thyroid gland, then they are distributed among the tissues.

The next step is to scan the organ using a specialized counter in a gamma camera. The information is visible on the monitor screen and recorded on the computer.

On the monitor screen, a mathematical version of the thyroid gland is viewed in a three-dimensional image. Such an image is called a scintigram.

Gamma - the camera assumes the presence of:

detector;
photomultiplier;
replaceable lead collimators;
a device that captures the resulting image.

Using this method, not only the location of the thyroid gland is easily determined, scintigraphy shows its activity. In thyroid cancer, lesions are detected, the nature of their changes, a clear image of metastases is visible. It is possible to visually see both lobes and assess the state of their hormonal activity, defined as "cold" or "warm".

A cold state is considered with low thyroid activity, a warm state when increased activity is observed. Both states of active activity of the organ have deviations from the norm, and only the scintigraphy method makes it possible to detect this effect in just 20 minutes, in addition, to obtain an accurate picture of all areas of the thyroid gland that have warm and cold anomalies.

Organ scintigraphy is carried out mainly after ultrasound, so the purpose of the study is to evaluate the detected pathological changes. The definition of "cold" zones usually indicates the formation of a colloid cyst, but perhaps in about 7% that this is a tumor. "Hot" zones indicate the functional autonomy of the body.

Preparation for thyroid scintigraphy

The technique itself is quite simple and no special preparation is required for it.

The preparatory process will not disturb the patient's usual rhythm of life:

Usually, to obtain reliable information, it is recommended to stop the use of medicinal iodine-containing drugs.
Doctors do not recommend other studies for three months, for example, kidney urography, magnetic resonance scanning.

Before going to the procedure, two conditions must be met:

to keep the bladder empty;
don't eat anything, don't even drink tea.

The preparation procedure is as follows: in the morning, the patient is offered to drink a capsule of the radioisotope of iodine on an empty stomach. During the day, iodine will actively accumulate in the body.

After 24 hours after taking the drug, the patient can undergo a scan.

Since the accumulation of the radiopharmaceutical on the thyroid gland will be sufficient to carry out the diagnostic procedure itself. The duration of the procedure is not more than half an hour

Scintigraphy is performed for those patients who:

an incorrect location of the gland was found;
there is an innate unusual development of it;
nodes, neoplasms;
in the differential diagnosis of thyrotoxicosis;
to study the detected neoplasm of the organ in order to determine the nature of the process.

Thyroid scintigraphy is a simple manipulation, it does not bear negative consequences. It can be carried out even by babies.

The image enables the oncologist to diagnose:

the presence of malignant or benign neoplasms;
determine swelling or inflammation;
organ hyperactivity;
examine goiter;
the presence of cancer.

Thyroid scintigraphy makes it possible to study the visually obtained data immediately after the end of scanning with a gamma camera. This radionuclide study of the thyroid gland allows physicians to compare color picture readings.

These indications facilitate the diagnosis of the disease.

A warm focus is a zone where an overestimated content of a radionuclide preparation occurs. In the picture, any of the shades of color: orange, yellow or red, which indicates this area. Too much accumulation indicates thyrotoxicosis or the formation of malignant nodes from hormone-producing cells.
The cold center indicates an underestimated content of radioactive iodine. The picture shows areas of tissue accumulation. This pattern is observed with cancerous lesions or cystic growths.

This study is used to assess the functional activity of nodular neoplasms. These nodes can contribute to the production of excess hormones or, conversely, contribute to a decrease in hormone synthesis.

This method is indispensable in cases where it is not always possible to diagnose by other methods, so the radionuclide method of diagnosis is used. This method allows you to get a clear image of a cancerous infection or a precancerous condition of an organ.

The introduced iodine-131 spontaneously decomposes quite quickly. Usually the dosage is calculated individually for each patient. For example, in Estonia, studies are carried out using Discovery NM / CT 670 equipment. The patient receives the results of the examination in Russian along with the disk, which makes it possible for doctors at home to carefully study all the indications, to see even the slightest changes in the organ.

Radioiodine therapy is treated with caution, but this method is relatively safe for both adult patients and children. It involves the receipt by the patient of the radioactive isotope of iodine I-131. Since radioactive iodine I-13 is used only for the treatment of various thyroid diseases.

In this case, the ability of the thyroid organ to accumulate iodine, radioactive iodine, is used. It irradiates the cell of the organ from the inside, damaging it. Cancer-infected cells die. The treatment is painless, there are no complications and the risk of developing other pathologies.

This method of treatment does not pose a danger to other organs. Since the beta particles emitted by the I-131 only operate within 2 mm.

Radioiodine therapy is carried out for the treatment and prevention of:

It is used for treatment if it is impossible to completely remove the tumor.
Prevention by radioiodine therapy is performed when the tumor has already been removed, but so that the spread process does not go further.

During the treatment period is not recommended:

Take medicines containing iodine.
Do not apply iodine solution to the skin.
Do not eat foods containing iodine.
Preparation is required to begin a month before the start of the procedures.

In preparation for the procedure, it is imperative to follow a certain diet in order to prepare the thyroid gland. That is, the thyroid gland should experience iodine hunger. This will make it possible to absorb radioiodine actively. Usually, a diet is prescribed 2 weeks before admission, it must be followed for the entire course when diagnostics or treatment is carried out.

How long does iodine I-131 stay in the body?

Most of it is excreted naturally during the first 2 days, the rest decreases sharply, and after the eighth day it does not remain at all.

Content

Radioisotope study of the thyroid gland has long been successfully used in the research practice of medicine. The method reveals inflammatory foci of the organ, evaluates changes and its functioning in general. With significant research efficiency, the method is limited in use by a number of appointments.

What is a thyroid scintigraphy

The endocrine gland, popularly referred to as the "thyroid gland", produces hormones that control metabolism, body growth processes. It is able to absorb, accumulate and gradually remove isotopes, substances used for examination - this is the basis of the principle of scintigraphy. Thyroid scintigraphy or thyroid scintigraphy is a method of diagnosis, determination of the functionality of an organ, its disorders, and abnormalities using radioisotopes.

An isotope study of the thyroid gland involves obtaining radioisotopes by the body through intravenous administration or swallowing a capsule. Substances are distributed throughout the body through the blood, quickly accumulating in the thyroid gland. The area under study is scanned in a gamma camera, data for visualization and analysis are transferred to a computer device, where a scintigram is created - a model of the object under study in mathematical and volumetric terms.

Is thyroid scintigraphy harmful?

For the thyroid gland, the main pathological danger is cancer, which is detected by such a study. Scinting in the early stages diagnoses functional deviations from the norm, so that they can be treated in a timely and successful manner, to maintain health. For the procedure, radioisotope elements are used: technetium, iodine in such an amount that their radiation is easily captured without exerting a toxic effect on the body. Injected substances are quickly excreted with feces and urine.

If a radionuclide study is carried out taking into account contraindications for it, there is no harm to thyroid scintigraphy: the method is harmless and painless. Pregnancy is a contraindication. With lactation, you can start feeding the baby a day after the examination, after decanting milk. The dose of radiation received is so small that scintigraphy is also performed on children. With a total diagnosis of the organ, it is allowed to do the procedure twice a month.

Thyroid scintigraphy - indications

Radioisotope scanning of the thyroid gland or parathyroid glands is done on a need-to-know basis. The method is used to detect hormone-producing adenoma in people with elevated levels of parathyroid hormone or enlarged parathyroid glands. There are specific indications for thyroid scintigraphy (in other cases, a different examination is used):

incorrect location of the gland;
the formation of specific antibodies;
congenital anomalies, pathological development (additional shares);
the presence of nodes, the detection of neoplasms;
hyperfunction, thyrotoxicosis, its differential diagnosis;
with radiation exposure after therapy or accidents.

Thyroid scintigraphy - preparation for the examination

Despite the fact that scintigraphic tomography requires extensive preparation, the procedure itself is simple, the preparation for it does not violate the usual routine and way of life. Strict adherence to the rules contributes to the accurate result of the survey analysis. Preparation for thyroid scintigraphy includes the following:

For three months, other studies using X-ray contrast agents (urography, angiography, MRI) are not recommended.
A month before the event, seafood saturated with iodine is excluded from the diet.
Amiodarone (Kordaron) is canceled in 3-6 months.
For 1-2 months, medications containing iodine are stopped, including thyroid hormones - for 3 weeks.
For a week, it is undesirable to use drugs: Aspirin, Propylthiouracil, Antibiotics, Mercazolil, Nitrates.

Scintigraphy sequence:

In the morning a day before the procedure, the radioisotope of iodine is drunk on an empty stomach or an intravenous injection is given, after 30 minutes you can eat.
The next day, a scan is performed.
Before starting, remove jewelry, dentures, and other metal objects.
The patient is placed on his back, the whole procedure lasts about half an hour.

Thyroid scintigraphy - side effects

From the point of view of the influence of radiation, the examination is safe, and the side effects of thyroid scintigraphy in 99 percent are associated with allergies and personal intolerances. Temporary changes in blood pressure may occur, there may be an urge to urinate, there may be rapidly passing vomiting or a feeling of nausea. In rare cases (according to patients' reviews), there is a fever, a blush. If the patient does not experience weakness, dizziness, itching at the injection site, the attending physician should be informed.

Results of scintigraphy

Thyroid scintigraphy is prescribed in order to detect nodes, evaluate their activity, the ability to independently produce hormones: identify cold and hot nodes. In the "cold" ones, radioisotopes do not accumulate, which indicates the tumor nature of the disease or goiter of the colloid-nodular type. In the "hot" there is an accumulation of radioisotopes, that is, the nodes produce hormones without the control of thyroid-stimulating hormone, which is a sign of toxic conditions of adenoma or multinodular goiter.

The results of thyroid scintigraphy make it possible to recognize an increased or decreased intensity of absorbed radioisotope elements by the entire organ. This indicates such problems of the parathyroid (parathyroid) glands:

overestimated and uniform consumption - diffuse toxic goiter;
low consumption - hypothyroidism.

Thyroid scintigraphy is a study in which the structure and functions of the organ are studied. To do this, a special contrast agent is injected into a vein or the patient swallows a capsule with a radiopharmaceutical preparation for subsequent imaging of the radiation.

What it is

Scintigraphy is an examination based on the fact that the thyroid gland can capture, store and excrete iodine. She consumes this microelement more than other organs, because. it is needed for the production of hormones. So you can examine the health of the thyroid gland.

When scintigraphy is performed, preparations of radioactive iodine 131 or technetium isotope are introduced into the body. Such substances are absorbed and then transported through the tissues of the body. In the thyroid gland, they accumulate much faster.

Then, the anterior neck area is scanned in the gamma camera (a special counter is used for this). The data obtained during scintigraphy are transferred to a computer. Here their analysis takes place, it allows you to create an accurate mathematical and three-dimensional model.

Scintigraphy does not involve vein puncture; iodine preparation is administered orally into the body. In some cases, it is administered intravenously.

Sometimes the study is performed after the removal of the thyroid gland. Isotopes do not take part in the synthesis of thyroid hormones. They are excreted from the body with the kidneys, which minimizes possible side effects.

Scintigraphy helps to determine the exact location of the thyroid gland, and with the help of radioisotopes, the doctor is able to identify areas of their accumulation and intensity. If there are malignant neoplasms in the thyroid gland, then such a diagnostic examination helps to determine the localization of metastases.

Indications and contraindications

Scintigraphy is prescribed in such cases:

anatomically incorrect location of the organ;
anomalies in the development or structure of the gland;
differential diagnosis of thyrotoxicosis;
suspicion of malignancy;
the presence of non-functioning nodes in the body;
disorders of calcium metabolism caused by dysfunctions;
diffuse toxic goiter;
Plummer's syndrome or thyrotoxic adenoma;
pituitary adenoma;
de Quervain's syndrome;
autoimmune thyroiditis;
autoimmune ophthalmopathy;
vegetative dystonia.

Scintigraphy has an absolute contraindication for carrying out - pregnancy at any time. Diagnosis is also not performed if the patient has an intolerance to any radioactive drug.

Relative contraindications include breastfeeding. Women are advised to refrain from feeding the child for the time of complete removal of the drug from the body (no more than 48 hours).

Where is scintigraphy done

The procedure is performed in large diagnostic centers, where specially trained personnel work. Such centers should have a medical nuclear reactor that can synthesize isotopes. The procedure is an expensive and high-tech examination. Scintigraphy is performed only in the direction of the endocrinologist.

All diagnostic centers comply with all safety measures related to the use of radioactive materials. Such objects are protected in accordance with the current legislation.

Training

Before the examination, it is forbidden to take all preparations containing iodine for a month. The exception is drugs prescribed for the treatment of diseases. Within 3 months, it is not recommended to do all studies using radiopaque preparations.

A week before the scintigraphy will be carried out, it is not recommended to take drugs:

propylthiouracil;
streptocide, Biseptol and other sulfa drugs;
Mercazolil;
acetylsalicylic acid;
nitroglycerin and other nitrates.

You can not eat before such an examination. The patient drinks an iodine isotope preparation (or technetium). The next day, a scan is performed. The dosage of such isotopes is safe for health.

A doctor can make a scintigraphy based on the technetium-99 isotope. In this case, specific preparation for the examination is not required. This substance is not involved in the production of thyroid hormones. In some cases, it is recommended to conduct an additional examination based on iodine isotopes.

How the study is done

Scintigraphy involves the use of radiopharmaceuticals. MIBI and Technetrile are labeled with the technetium-99 isotope. Pertechnetate is a solution of pure radioactive technetium. It is administered to the patient intravenously. The preparation of radioactive iodine 123 is used in the form of tablets for oral administration.

After the patient has taken the drug with technetium or iodine, he comes to the diagnostic laboratory for scanning and fixation with special gamma radiation devices. To do this, he needs to lie on the couch on his back. With the help of the device, each node of the thyroid gland is measured, a high-quality image is broadcast on the monitor.

For early detection of oncological pathologies, scintigraphy is performed using a gamma camera. It records the amount of radiation emitted from the surveyed areas. The camera includes:

detector;
photomultiplier;
lead collimators;
a computer with specialized equipment that captures an image based on information about the distribution of a radioisotope preparation.

During the procedure, the patient is in the chamber for no more than 30 minutes. After the scintigraphy is performed, the subject can leave the hospital: no additional procedures are required. Since isotope preparations are excreted from the body within a day after scintigraphy, after radioisotope diagnostics there is no need to take additional medications, limit diet and physical activity.

Deciphering the results

Scintigraphy is performed to detect nodular formations in the thyroid gland and determine the degree of their activity. The doctor determines how actively they form hormones.

In this regard, the nodes are conditionally divided into cold and hot. Cold knots do not accumulate radioactive iodine. This happens with nodular colloid goiter or tumor pathologies of the thyroid gland. In hot nodes, a radioactive isotope accumulates constantly. This happens with toxic goiter or adenoma.

Scintigraphy has the following advantages:

radiation exposure does not cause any harm to the patient, only in rare cases allergic reactions develop;
a small amount of gamma radiation helps to conduct this type of thyroid examination every month;
the procedure makes it possible to evaluate not only the structural features of the gland, but also its functions;
scintigraphy can quantify the degree of thyroid involvement;
does not require complex preparation, the patient needs to limit the use of iodine-based products and stop taking medications that can adversely affect the results of the examination;
such a diagnosis does not cause pain;
after scintigraphy is performed, no additional medications or restorative procedures are required.

The main disadvantage of scintigraphy is its high price.

Among the shortcomings of such a survey can be identified:

less sharp image than with computed tomography or magnetic resonance imaging;
the duration of the procedure itself;
patient contact with radioactive elements;
high cost;
comparative inaccessibility, since scintigraphy can be performed only in a few large cities of the country.

The thyroid gland performs the most important function in the body, since it produces thyroid hormones, without which no organism can exist.

To diagnose thyroid or parathyroid pathologies, deep diagnostics are sometimes required using radiopharmaceuticals, for example,.

What it is?

A scintigraphic study is a functional visualization of the examined tissues, which consists in the introduction of preparations of radioactive isotopes and obtaining images through the radiation emitted by them.

The procedure is carried out on a special apparatus - a gamma tomograph after the introduction of a radiopharmaceutical. As a result, after the diagnosis, images are obtained, called a scintigram.

Before the study, the patient is injected with one of the drugs like technetium or radioactive iodine.

The glands absorb the radiopharmaceutical well, as a result, after its administration, it is possible to assess the activity of individual sections of the thyroid gland or parathyroid glands. These areas on the pictures are hot or cold nodes (depending on the degree of activity).

In cold areas, the drug does not accumulate, which means that they do not produce hormonal substances. On the pictures, they are displayed as blue-blue areas and show colloid cysts or tumor formations.

Hot spots are detected when a radiopharmaceutical accumulates in certain areas of the thyroid or parathyroid glands. The presence of such zones indicates hypothyroidism, toxic adenoma, diffuse or multinodular toxic goiter, functional glandular autonomy, etc.

Scintigraphy is considered the most highly sensitive diagnostic method that helps to identify the presence of pathogenetic processes in their early stages, and the introduced markers do not harm the body and are naturally eliminated from the body.

In this case, the irradiation is recorded much lower than with conventional radiography.

Indications and contraindications

Scintigraphic diagnostics of the thyroid gland and parathyroid structures is prescribed in various clinical situations, such as:

Abnormal arrangement of organs;
thyrotoxicosis;
Nodular tumors;
Elevated levels of parathyroid hormone;
Hyperparathyroidism;
Osteoporosis of unknown origin;
Suspicion of, or hyperplasia.

The use of drugs with radioactivity does not imply high radiation rates, therefore there is no risk from the procedure.

However, scintigraphic examination is contraindicated in pregnancy, allergic intolerance to the contrast agent. In addition, it is not recommended to diagnose those patients whose weight is more than 150 kg.

The procedure is performed for lactating women, children of the first year of life and elderly patients. If scintigraphic diagnostics was carried out for a nursing woman, then breastfeeding is stopped for 2-3 days until the radiopharmaceutical is completely eliminated from the body.

Preparation for scintigraphy of the thyroid and parathyroid glands

Before diagnosis, it is necessary to inform the doctor about the existing drug allergies and other intolerable substances.

In addition, three months before the study, you need to abandon any x-ray contrast procedures, and a month before taking iodine-containing drugs.

How is the research going?

The procedure of radioisotope diagnostics takes approximately 20-30 minutes. This is a non-invasive study, before which the patient is given an injection of a radiocontrast agent. Sometimes the patient is given the drug in the form of a capsule instead of an injection.

For a certain time, this radiopharmaceutical accumulates in the parathyroid glands or thyroid gland, after which the doctor scans the patient in a gamma camera.

As a result of the procedure, the specialist receives a scintigram, which displays pathological areas, if any. Typically, photographs are taken in three stages:

10 minutes after drug administration;
In 2 hours;
After 3 hours.

During the scan, the patient needs to lie still in order for the quality of the images to be high. If there is a need for re-diagnosis, then it is carried out after 2 months, not earlier. Usually, a second study is prescribed when thyroid cancer is detected, against which there is an increase in thyroglobulin hormone.

Complications

The radioisotope diagnostic procedure usually does not cause any complications, but in some cases, adverse reactions are possible, such as:

Frequent urination;
allergies;
Pressure surges, etc.

Some patients develop a blush or feel hot flashes during the procedure, which by no means can be considered a complication.

Sometimes there is an increase in heart rate or an increase in blood pressure, but these are reversible deviations that soon disappear on their own. The radiation level during the study is very low, so there is no need to be afraid of it.

Interpretation of results

The patient can receive the results in half an hour or a few days after the study.

The interpretation of the results describes hot and cold zones.

Cold patches are often indicative of a colloid nodular goiter or tumor and require further biopsy diagnosis.

Hot knots indicate accumulation of the radiopharmaceutical, which indicates the presence of cellular structures that absorb the radiopharmaceutical. A similar picture is observed with toxic goiter or toxic adenoma.

Where to do an examination in Moscow?

In the capital, you can undergo scintigraphy at many medical institutions, such as:

Central Design Bureau of the Russian Academy of Sciences;
CLINICMID;
OAO "Medicine";
FMBC im. Burnazyan;
Volyn hospital;
Central Design Bureau No. 2 Russian Railways;
GKB im. Pirogov;
MEDI etc.

Cost of scintigraphy of the thyroid and parathyroid glands

The procedure is quite affordable and will cost about 1100-9800 rubles.

Scintigraphy helps to identify many pathological processes in the thyroid gland and parathyroid glands even at the initial stages of their development, which favorably affects the therapeutic process, increasing the chances of a complete cure.