Thyroid scintigraphy: what it is, what it is for, preparation for a thyroid examination. What is thyroid scintigraphy, why is it needed? Radioisotope thyroid scan preparation

- this is a check of the structure and functioning of the thyroid gland by introducing a contrast solution into a vein or swallowing a capsule with further monitoring of its radiation. Such an examination is not carried out for everyone, because he has clear indications.
These are the following cases:

Abnormal placement of the gland;

Numerous (over six in both lobes) formations of nodular type;

How is a scintigraphic examination carried out?

As part of the examination, special radioactive components are introduced into the human body, which are combined with special pharmacological drugs. This mixture with the natural blood flow is in the organ under study. Then the received data is processed by a computer. As a result, the doctor receives all the information he needs. Obviously, the implementation of scintigraphic examinations requires a high-quality and fairly wide equipment base. No less necessary will be the work of specialists in the relevant specialization.

Dosages of the introduced isotope are completely harmless, because this component is extremely quickly destroyed and eliminated. In the presented situation, the ratio is much less than with the usual examination using X-rays. In most cases, there are no allergic reactions to the injected solution.

Preparation directly for the thyroid scintigraphy takes no more than half an hour. It is during this period of time that the radiological pharmaceutical preparation will have time to accumulate in the organ in the required ratio. The duration of the examination itself will be no more than 20 minutes.

There are also special medical requirements, which consist in stopping the use of a wide variety of drugs. So, 30 days before the implementation of scintigraphy, you should stop using drugs that contain iodine. For patients with cardiac diseases, the use of blockers is undesirable. Food does not affect the quality of the research being carried out. While drugs can accumulate in the tissues of the thyroid gland. In this regard, the results of the study may be uninformative or implausible.

In any case, it is the endocrinologist who referred the patient for this examination, who must explain in detail where exactly the scintigraphy of the endocrine gland is done. It is his duty to tell about what are the basic standards of preparation for this survey. The endocrinologist should also discuss future treatment tactics and the replacement of main drugs.

Scintigraphy is an expensive examination method that requires high medical qualifications from the staff. Along with this, access to a medical nuclear reactor is necessary, which will make it possible to obtain isotopes if necessary. Given the half-life of the material, which is six hours, it can be quite difficult to deliver the agent in the required ratio and on time to some areas. This explains the fact that scintigraphic equipment is located mainly in large cities of Russia.

It is mandatory to take into account the requirements for compliance with safety regulations and, given their potential danger, the protection of objects with materials of radioactive origin.

Side effects

This method of examination is safe in terms of radiation. Side effects after the endocrine gland examination procedure in 99% of cases are directly related to individual intolerance or allergic reactions.

Side effects include:

Allergic reactions to radioactive components;

Temporary increase or decrease in indicators;

Constant urge to urinate, as well as nausea or vomiting, which quickly pass.

After the procedure with the use of iodine, the patient in rare cases may experience such manifestations as a flush on the face or fever. If the patient experiences constant, weakness or itching on the skin after the injection, then it is necessary to inform your doctor or any of the medical staff as soon as possible.

In general, the radiation exposure received by the patient during the examination is so small that it is acceptable to perform scintigraphy many times. With a total study of the endocrine gland, it is permissible to conduct it twice a month.
Preparing for a Thyroid Scan

A prerequisite for a scintigraphic examination is a thorough preparation for it. So, one month before the procedure, seafood that is saturated with iodine should be excluded from the menu. 3 months or six months before the examination, depending on the nuances in the state of health, the use of the substance amiodarone (Cordarone) is canceled. This is an anti-arrhythmia drug. One to two months before the scintigraphy, it is recommended to avoid prescribing X-ray contrast-type drugs and those that contain iodine.

One week before the scintigraphy, it is undesirable to use such means as:

Propylthiouracil;

Mercazolil;

Sulfanilamide type antibiotics (streptocide, biseptol);

Nitrates (nitroglycerin, monosan, kardiket, nitrosorbide).

Failure to comply with these rules can provoke a distortion of the survey results. This is due to a decrease in the area of capture of the radiological pharmaceutical by the cells.

It should be noted that a scintigraphic examination involving the use of the 99Tcm technetium isotope does not require any specific preparation. This is due to the fact that technetium does not take any part in the production of thyroid hormones. The rate of its accumulation does not depend on the use of certain drugs. However, in some cases, another additional examination using an iodine-based radiological pharmaceutical may be required.

Thus, scintigraphy of the endocrine gland is an examination that will make it possible to put an end to disputes over the diagnosis. This examination is used only in exceptional - problematic - cases, and it requires some preparation, both on the part of the patient and the specialist. Subject to all the above conditions and recommendations, scintigraphy guarantees a 100% accurate result.

Education: Diploma of the Russian State Medical University N. I. Pirogov, specialty "Medicine" (2004). Residency at the Moscow State University of Medicine and Dentistry, diploma in Endocrinology (2006).

The development and expansion of the diagnostic capabilities of modern medicine 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 using 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 makes it possible to minimize 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, such a thyroid disease 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:

reception of radiopharmaceuticals;
scanning.

If iodine isotopes are used during the scintigraphic examination, then 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 a scan is started after a few hours.

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 the radiation coming from the patient with the help of a crystal (detector) that reacts to isotopes with flashes, which, in turn, interacting with the 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" ones.

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.

This is a radiation research method based on the ability of the gland tissue to absorb iodine. Unlike other research methods, thyroid scintigraphy allows you to get double information: both about the structure of the organ and about its function. With the participation of iodine in the follicles of the gland, thyroid hormones T3 and T4 are synthesized, which play an important stimulating role in all body functions. The less the gland tissue absorbs iodine, the less hormones are formed, and vice versa. Accordingly, hypothyroidism or hyperthyroidism develops.

To study the gland, "labeled" iodine atoms - radioisotopes are used, they are obtained by the action of powerful energy, leading to the emission of gamma rays by the atom. These isotopes of iodine include I(123) and I(131), as well as technetium TC(99). When a certain dose of iodine isotope is introduced into the body, it accumulates in the gland, after a while the patient is placed under a recording gamma camera. Its principle of operation is based on crystals, which, when gamma rays from the gland hit them, begin to glow.

These signals are received, converted and analyzed by a computerized recorder, which converts them into an image that is printed on paper. Hence the name of the method: from the Latin scintillo - to sparkle, sparkle, and the Greek grafo - to write, that is, to record the sparkle. The method is not new, it was invented in 1911, entered medical practice in the 50s of the last century, but it is constantly being improved, and modern gamma scanners make it possible to obtain a three-dimensional (3D) color image of an organ.

Important! You should not be afraid of radiation during scintigraphy. The dose of the isotope is minimal, and it is excreted from the body very quickly.

Why is a thyroid scan done?

Research using radioisotopes - scintigraphy, or scintigraphy of the thyroid gland, has its own indications and contraindications, like any study associated with radiation.

Thyroid scintigraphy is done if the patient:

anomaly in the development or location of the gland, detected by ultrasound;
the presence of nodes in the gland;
the presence of a tumor;
to clarify the nature of the pathology detected by ultrasound;
to determine the function of the gland and the formations (nodes) found in it.

The only contraindication for the study is pregnancy. Examination of a woman during breastfeeding is possible provided that she refrains from feeding within a day after the administration of the drug.

Important! In case of iodine intolerance, thyroid scintigraphy is performed with Tc(99) technetium, which does not cause side effects.

How to prepare for the examination?

Preparation for thyroid scintigraphy is quite simple, without disturbing the usual daily routine and diet. You need to fulfill only 2 conditions:

Must have passed at least 3 months after the last study related to radiation: X-ray, computed tomography, angiography, MRI with the introduction of a contrast agent.
1 month before the scintigraphy, stop taking medications containing iodine, as well as following a diet rich in iodine.

About all this, you need to warn the doctor in advance and decide on the timing of the study.

How is a scintigraphy performed?

Those who did thyroid scintigraphy are well aware that this procedure is quite simple, it takes place in 2 stages:

The introduction of the drug.
Scanning in a gamma camera.

On the 1st day in the morning, the patient comes to the clinic, he is injected with a radioactive isotope - intravenously, or given to drink it. After 24 hours, when the radioisotope accumulates in the gland, the patient comes again. It is placed under the gamma scanner, the device scans in several projections, and the image is recorded. On average, the procedure takes 30 minutes.

Important! Where can a thyroid scintigraphy be done? It is carried out in the departments of radioisotope diagnostics of oncology dispensaries, public and private clinics - only in the direction of an endocrinologist.

Can there be side effects?

Quite rarely, side effects are observed with thyroid scintigraphy. They appear in 2 forms: iodine intolerance and vegetative reactions. With iodine intolerance, the patient develops dizziness, general weakness, an itchy rash on the skin, and swelling. Vegetative reactions are manifested by a short-term feeling of heat, a flush to the face, redness of the skin, which disappear on their own during the day.

Important! To avoid side effects, allergies, the procedure can be performed using the radioisotope of technetium Tc(99).

What does scintigraphy reveal, how are its results evaluated?

This method allows you to determine:

The functional activity of the gland - according to the number of radioisotopes of iodine or technetium absorbed by it. The greater the glow of the organ tissue, the higher its activity.
The presence of nodes - "hot" and "cold" areas in the tissue.

Neoplasms in the gland (cysts, goiter, tumors) differ from normal tissue in their ability to accumulate iodine. Normally, on the iron scintigram, it is uniformly dark in color, symmetrical, and has the shape of a butterfly. The darker areas are called "hot" nodes. On a color scintigram, they are colored orange and red, indicating areas of increased activity in toxic goiter, nodular thyroiditis.

"Cold" nodes are lighter areas, and in color images they have a color from blue to purple. Point to zones with reduced function, which happens with cysts and tumors, including cancer.

Why do a scintigraphy of the parathyroid glands?

What are the parathyroid glands and why do they do scintigraphy? The parathyroid glands are located behind and on both sides of the thyroid gland, their number can be from 4 to 12. They secrete 2 types of antagonist hormones: parathyroid hormone, which increases calcium levels, and calcitonin, which, on the contrary, promotes the excretion of calcium from the body.

Thyroid scintigraphy

The essence of the method: thyroid scintigraphy is a method of radioisotope study of the functional activity of thyroid tissue and nodular formations. Scintigraphy allows you to judge the morphology, topography and size of the thyroid gland, identify its focal and diffuse changes, identify and differentiate "hot" (hormonally active) and "cold" (functionally inactive) nodes of the gland.

The advantage of thyroid scintigraphy is the ability to visually assess the level of hormonal activity of normal thyroid tissue and foci of compaction.

Thyroid scintigraphy has a low radiation exposure: the radiation dose is less compared to other methods (in particular, x-rays), and the radioisotopes used are quickly washed out of the body.

Thyroid scintigraphy helps to detect ectopia or possible fragments of thyroid tissue after removal of the gland. Thyroid scintigraphy cannot accurately diagnose the benignity or malignancy of the node, although it suggests the presence of oncological alertness. Thyroid scintigraphy reveals metastatic lesions of regional (submandibular, cervical) lymph nodes.

Disadvantage: thyroid scintigraphy serves as a clarifying diagnostic method and, unlike computed tomography and magnetic resonance imaging, ultrasound, has a lower resolution and provides a less clear image of the organ.

Indications for research:

Adenoma of the parathyroid glands;

Thyroid adenoma;

autoimmune thyroiditis;

Hyperthyroidism;

Hypothyroidism;

Diffuse toxic goiter;

thyroid cancer;

Thyroiditis;

Nodules and cysts of the thyroid gland.

Conducting research: 20–30 minutes before thyroid scintigraphy, a microdose of a radiopharmaceutical (iodine isotope 131I, 123I or technetium 99mTc) is administered intravenously to the patient, which can accumulate in the thyroid tissue and in the nodes, and then its distribution is assessed using a series of scintigrams performed for 15 -20 minutes.

Contraindications, consequences and complications: an absolute contraindication is an allergy to the substances that make up the used radiopharmaceutical. Relative contraindications - pregnancy, breastfeeding, the general serious condition of the patient.

Preparation for the study: before thyroid scintigraphy, it is required to stop taking any iodine-containing drugs: L-thyroxine 3 weeks before the study, mercaptisol and propylthiuracil - 5 days before.

Thyroid scintigraphy should not be performed earlier than three weeks after computed tomography using a contrast agent containing iodine.

Deciphering the results of the study must be carried out by a qualified radiologist, the final conclusion based on all the data on the patient's condition is made by the clinician who sent the patient for examination - an endocrinologist, gastroenterologist, surgeon, oncologist and other specialists.

Next chapter >

Thyroid scintigraphy is a functional method for studying its activity. In addition, thanks to this method, the abnormal location of the gland and the state of the nodular formations present in it are determined, cancer metastases are detected.

For the vital activity of the thyroid gland and the production of the required amount of thyroid hormones, a sufficient amount of iodine must be supplied to the body. This research technique is based on this - the thyroid gland will actively capture any iodine offered to it from the outside.

A radiopharmaceutical (RP) containing isotopes of iodine-123 (123I), iodine-131 (131I) or technetium pertechnetate-99 (99mTc) is injected into the patient's body. The rate of iodine uptake by thyroid tissue is 100 times higher than by other body tissues. The radioactive iodine or technetium accumulated in the thyroid gland begins to decay into isotopes, the signals of which are recorded by a scanner in a gamma camera.

According to the intensity of radiopharmaceutical accumulation, the shape and position of the gland, the presence of a “cold” (weak accumulation) or “hot” (high accumulation) node are determined. The amount of radiopharmaceuticals is such that it is easily fixed by special equipment without harm to the body.

Thyroid scintigraphy is performed at the second stage of diagnosing thyroid diseases, it is considered an additional method that completes routine examinations (ultrasound, hormonal profile, puncture biopsy), therefore it has few indications for:

Absence of the thyroid gland in a typical location;
Retrosternal goiter;
Goiter of the root of the tongue;
Toxic thyroid adenoma;
Thyrotoxicosis;
Metastases of highly differentiated thyroid cancer to other parts of the body, lymph nodes;
Confirmation of complete absence of thyroid tissue after total strumectomy.

Thyroid scintigraphy is an absolutely painless and harmless procedure for the body. Radionuclides for research are selected in such a way that their effect on the body does not differ from the effect of natural background radiation. The drugs will differ only in the ability to emit rays, allowing you to determine the location, quantity and distribution. Each radiopharmaceutical undergoes a long cycle of studies that determine the effect on the body, and is approved by the commission of the Ministry of Health only after testing. The dosage of the radiation received is so small that a second scintigraphic examination can be carried out after 14 days.

It is not recommended to perform other studies related to the administration of a contrast agent 90 days before scanning (MRI or CT with contrast, angiography, urography). It is recommended to stop taking iodine preparations 30 days before the study (cough syrup, Lugol's solution, multivitamins). Thyroid and antithyroid drugs are canceled 3 weeks before the study. Glucocorticoids, anticoagulants, phenothiazines, salicylates are canceled 1 week before the study.

The preparation of the patient and the timing of the procedure depend on the preparation with which the study is carried out:

Thyroid scintigraphy is performed after complete absorption of the drug. To do this, the patient is placed in a gamma camera, special sensors begin to receive signals from the thyroid gland, which has accumulated radiopharmaceuticals. Information is transmitted directly to a computer, where a color image of the gland is created. The intensity of staining depends on the degree of accumulation of the isotope. Normally, the thyroid gland has the appearance of a butterfly, the lobes are presented in the form of two dark ovals, evenly colored and with clear contours. The duration of the study is 30 minutes.

The choice of radiopharmaceutical depends on the diagnosis and the planned further treatment. If an oncological lesion, adenoma and nodular goiter are suspected, 99mTc is injected. If toxic goiter is suspected and 131I therapy is planned, iodine isotopes are used for the study, the capture of which is used to calculate the necessary therapeutic activity of 131I. But in this case, 123I is used for scanning, which reduces the radiation load on the patient and allows you to start therapy earlier, since there is no residual beta radiation.

Deciphering the results

Thyroid scintigraphy shows the degree of absorption of the radiopharmaceutical by the gland and its distribution. Each pathology has a characteristic picture: (the picture is clickable)

Diseases of the endocrine system are the scourge of modern society. And the most common among them are pathologies of the thyroid gland. To recognize what exactly caused a particular pathology, various diagnostic studies help, one of which is thyroid scintigraphy.

What is the principle of this study, how is it carried out, in what cases is it prescribed, and are there any contraindications for its implementation?

Scintigraphy is one of the methods of functional diagnostics, which allows visualization of the organ under study. The principle of this method is the use of radioactive isotopes, which are introduced into the patient's body either orally or intravenously. When interacting with isotopes, the organs begin to emit radiation, which is determined by the scintillation gamma camera, displaying the image on the monitor. Considering that radiopharmaceuticals labeled with gamma-emitting radionuclides are used in diagnostics, this method has the definition of "radionuclide study".

Consider the anatomy of the body allows a more familiar method of ultrasound diagnostics. However, she is powerless when the thyroid gland changes its location. With scintigraphy, you can easily determine the thyroid gland, even if it is located in the retrosternal space, and detect a violation of its functions.

Thyroid scintigraphy is performed if it is necessary to determine the state of hormonal activity of its lobes. With a decrease in activity, the areas are defined as cold, and with an increase, as hot.

Despite the fact that this research method appeared quite a long time ago, there are no more than two hundred gamma cameras in Russia. At the same time, scintigraphy is the prerogative of large medical centers. Therefore, residents of the regions most often have to look for where to do thyroid scintigraphy. Most of the scintillation gamma cameras are located in the Russian capital. But in European countries, this procedure is carried out in every outpatient clinic. For example, one of these countries is Estonia.

Thyroid scintigraphy involves the use of radioisotopes of iodine 123 and 131, or technetium 99. Despite the fact that the procedure itself does not harm the human body, it is not indicated for all pathologies of the thyroid gland.

Normally, the thyroid gland consists of two lobes, which, in turn, consist of follicles. In the cells of the follicles, iodine is accumulated and stored, which, through biochemical processes, is converted by them into thyroid hormones.

A scintigraphic study is based precisely on the property of the thyroid gland to accumulate and absorb iodine. During normal functioning, the thyroid gland is able to absorb only a certain amount of iodine, from which thyroid hormones are produced. If, after the administration of a dose of a radiopharmaceutical, the thyroid gland has absorbed too much of it, this indicates the development of thyrotoxicosis. If, on the contrary, any part of the thyroid gland remains inactive and does not absorb iodine, hypothyroidism is diagnosed.

In most cases, the study of the thyroid gland shows focal absorption of iodine isotopes, when different parts of the organ react differently to the radiopharmaceutical. This may indicate the presence of diffuse nodes or a tumor. Thyroid scintigraphy is also prescribed for malignant neoplasms. In this case, this method allows you to determine not only the location of the malignant tumor, but also the location of the spread of metastases.

It should be noted that the introduction of radioactive iodine is not contraindicated in thyrotoxicosis, since this substance does not take part in the formation of thyroid hormones. Isotopes are very quickly excreted from the body with feces and urine.

Scintigraphy is considered the most informative study of the thyroid gland for good reason. This procedure is very simple and does not require any special training. A patient who is shown this research method will not have to change the daily routine. Only the following conditions must be met.

If the patient is taking iodine-containing drugs, they should be stopped one month before the planned study. The only exceptions are medicines used to treat diseases. However, it is necessary to warn the doctor about their intake, as they can distort the results of the study.
3 months before scintigraphy, it is not recommended to undergo other studies that involve the use of contrast agents, for example, kidney urography.

For the procedure, the patient will have to visit the medical center twice. He must first come to the procedure on an empty stomach in order to take the radiopharmaceutical. Then he goes home and returns exactly 24 hours later for the direct procedure. At the same time, breakfast is no longer a contraindication.

After preliminary preparation associated with the introduction of isotopes, the patient is directed to a gamma camera, which perceives their radiation. The passage of scintigraphy takes no more than half an hour.

This procedure is not prescribed for all patients suffering from thyroid diseases. It is appointed only in exceptional cases.

If the thyroid gland is incorrectly located, and the ultrasound scan did not allow it to be visualized.
In the presence of any congenital anomalies in the development of the endocrine organ.
To determine the number and functions of nodular formations.
In the differential diagnosis of hyperthyroidism.
If a tumor is suspected. In this case, scintigraphy allows you to determine the nature of their development.

Most often, a radionuclide study is used to identify and evaluate the activity of nodular formations. What is a thyroid scintigram? A scintigram is a three-dimensional image showing colored areas that are classified by their ability to store iodine and produce hormones.

Cold areas. Their presence is the most common pathology. Such nodes do not accumulate radioisotopes, which indicates a nodular goiter. Most often, this pathology is benign.
Warm areas are rare. And in most cases, such formations are also benign. In this case, diffuse changes in the thyroid gland can be assumed, when its tissue captures iodine and produces a normal amount of hormones.
Hot spots indicate increased activity of thyroid cells, which produce hormones uncontrollably, not obeying the pituitary gland. This pathology is detected in 5% of patients, and most often requires surgical intervention.

Scintigraphy does not cause side effects and adverse effects. Therefore, if necessary, it is carried out even for infants, provided that radioactive iodine is replaced by technetium 99.

The following conditions are contraindications for its implementation.

Pregnancy regardless of the term.
If a woman is breastfeeding, breastfeeding should be avoided during the procedure. You can resume it only a day after its end.
A contraindication is an allergic reaction to any of the components that make up the radiopharmaceuticals. The main signs of an allergy are dizziness, general weakness and itchy skin.

Very often, this procedure is prescribed after surgery to remove the thyroid gland. A scintigraphic study allows you to determine with high accuracy whether a patient has metastases and in which organs they are located.

A feature of the procedure for thyroid cancer is that after taking radioactive iodine, it is necessary to wait a few days so that iodine can be distributed to all organs. To detect metastases, the patient is scanned not only the thyroid gland, but also other organs, so the procedure time is increased to 1.5 hours.

Pathologies of the thyroid gland are the most common among all diseases of the endocrine system. Diagnosis is carried out by various methods, while the main one is ultrasound. If its results are not enough for an accurate diagnosis, a thyroid scintigraphy is performed. The method involves irradiation, and resort to it only in controversial cases.

The thyroid gland affects the functions of almost every system in the body. Violations in its work negatively affect the human condition and worsen the quality of life, so do not delay the diagnosis. It is carried out, including through scintigraphy. This is a radionuclide method that evaluates the ability of glandular tissue to accumulate, absorb and excrete radioactive substances.

The study is carried out by introducing technetium 99, iodine 123 or iodine 131 into the body. These substances create radiation that the gamma camera captures and converts into electrical signals. They are displayed on the monitor in the form of a picture, or a scintigram. Based on these data, the diagnosis is specified.

To understand what scintigraphy is for examining the thyroid gland, its diagnostic capabilities will help. The following appears:

the exact location of the gland;
its size and shape;
performance;
the presence of foci of inflammation;
destructive phenomena.

Usually, scintigraphy is performed after ultrasound, so its main purpose is to assess pathological changes.

The method is important for the diagnosis of malignant tumors, it helps to clarify whether there are metastases. "Cold" zones indicate colloid cysts, and in 7% of cases - tumors, "hot" zones - functional autonomy of the gland.

Scintigraphy is carried out strictly according to the appointment of the endocrinologist. Indications:

hormonal disorders in the absence of the effect of medications;
formations in the gland (to clarify the location and size);
severe functional impairment;
thyrotoxicosis;
anomalies in the development and position of the thyroid gland;
suspicion of cancerous tumors;
diagnostics of "active" and "inactive" formations;
inflammation in glandular tissues;
undergoing chemotherapy;
monitoring the state of the thyroid gland after surgery.

Although radiation is expected, the doses are small, so scintigraphy is relatively safe. It is prohibited for infants and pregnant women - because of the risk of penetration of a radioactive substance to the fetus through the placenta, which is fraught with malformations.

With caution, the procedure is prescribed for allergies. It is difficult to predict the body's reaction to a radioactive drug.

Features of the procedure depend on whether scintigraphy is performed with technetium or radioactive iodine. The results are given to the patient along with the captured image disc.

The whole process, including preparation for it, takes 20-40 minutes. The patient must remove all metal objects. Further actions:

The drug is injected into a vein and wait 15 minutes until technetium is distributed in the body.
The patient lies on the table. At a distance of 20 cm from his neck, a gamma camera is installed and the image is started to be captured.
The results are sent for interpretation.

Preparing for a technetium thyroid scan does not involve a diet.

do not use iodine-containing medicines;
3 months do not undergo other studies;
follow a diet with the rejection of foods rich in iodine;
8 hours before the procedure, do not eat or drink anything, the bladder should be empty.

Procedure technique:

On the morning of the examination, the patient takes an iodine 131 capsule or a substance dissolved in water.
Wait 2 hours, all this time you can not eat anything.
The patient lies on a couch, a gamma camera is installed at a distance of 20 cm from his neck and an image is captured.
The procedure is repeated after 6 hours, after a day and after 2 days (depending on the decision of the specialist).

Radioiodine therapy is used both for the treatment of a tumor that cannot be completely removed, and for prevention - so that the oncoprocess does not spread further after the tumor is removed. The method often raises concerns, but it is safe even for children. The patient receives a radioisotope of iodine I-131 in an individually selected dosage. The substance irradiates the cells of the gland from the inside, but does not cause damage. Cancer cells die. Most of the drug is excreted in 2 days, and after 8 days it does not remain in the body at all.

Iodine 131 emits beta particles that operate within 2 mm. Scintigraphy with it is painless, does not cause complications, does not provoke other pathologies, and does not pose a danger to nearby organs.

In the decoding of scintigraphy indicate:

the location of the thyroid gland;
its size and shape;
the presence of nodes with excessive content of the radiopharmaceutical.

The third point indicates the presence of "cold" and "hot" spots in the gland. "Hot" ones indicate an increased accumulation of the radioisotope, which means that the production of hormones in these zones is increased. Possible nodular toxic goiter or toxic adenoma. There are practically no radioisotopes in the "cold" points, which indicates the inertness of the cells. A colloid or oncological formation is likely, a biopsy is needed to confirm the diagnosis.

If the substance is distributed evenly, and the thyroid gland intensively absorbs it, diffuse toxic goiter is possible. At a reduced level, hypothyroidism is detected, a deficiency of hormones due to reduced thyroid function.

The doses of radiation that the patient receives are safe. They are so small that scintigraphy can be performed twice a month. Side effects in 99% are caused by hypersensitivity to drugs. Possible:

allergic reactions to radioactive substances;
temporary change in pressure;
frequent urge to urinate, nausea, vomiting (pass quickly);
flush and fever (rare).

If, after the introduction of the substance for scintigraphy, you feel dizzy, the skin itches, you feel weak, you should immediately inform the medical staff about this.

In a public hospital, scintigraphy can be done free of charge under the MHI policy. If you need to undergo an examination faster, there is an option to contact one of the private medical centers. Prices in them vary between 3,000 - 8,000 rubles.

Specialists regarding scintigraphy note that this is a study of the thyroid gland, which is used only in controversial situations. The method allows you to make an accurate diagnosis if this could not be done according to the results of ultrasound. The body is exposed to negligible radiation, so with careful preparation and following all recommendations, the procedure is safe and gives a 100% result.

Specialists in endocrinology practice non-invasive methods for examining the thyroid gland. Modern technologies in radiation diagnostics make it possible to assess the topographic anatomy and functional activity of internal organs.

Imaging using radioisotope solutions includes a number of techniques for obtaining images that display the distribution in the body of radiotracer-labeled substances. One of the most informative and safe studies is scintigraphy. The main task of scintigraphy is the visualization and study of the kinetics of radiopharmaceutical drugs in the internal organs of a person.

Thyroid scintigraphy is a radioisotope study of the functional state of thyroid tissue and nodular formations, based on the assessment of the accumulation of a radiotracer in the required amount.

The study provides an opportunity to identify and obtain information about the following parameters of the thyroid gland:

the location of the organ;
the structure of the building;
functional activity performed;
to differentiate the state of hormonal activity of the lobes;
detect focal changes;
changes in the vascular pattern;
metastatic lesion of the lymph nodes;
possible oncological alertness.

In world medical practice, radioisotope scanning of the thyroid gland is used in the following cases:

Diagnosis of pathological changes in the gland.
The presence of nodular formations found on palpation.
Differential diagnosis of thyrotoxicosis.
Evaluation of the effectiveness of the surgical intervention.
Ectopic thyroid tissue.
Maintaining control over drug treatment of thyroid dysfunctions.
Diagnosis of possible residual tumor tissues and remote areas of the pathological process.

The study has contraindications for conducting:

pregnancy;
claustrophobia;
individual intolerance to the used radioisotope substances;
lactation period.

The option of conducting a scintigraphic examination during lactation still exists. Pancreatic scintigraphy is performed using technetium (99 mTc-pertechnetate).

Technetium is a short-lived isotope that appears in the body like iodine. These radionuclides are used in drugs with high specific activity. The trace element has been used in nuclear medicine since 1980. Among modern diagnostic procedures using radionuclides, technetium scintigraphy is the most frequently performed.

Pertechnetate is not included in the synthesis of hormones. The half-life is six hours, complete decay occurs within 60 hours. Technetium has a higher excretion than iodine-based radiopharmaceuticals. Technetium has a low dose load on the patient's body, due to which the isotope is used for research in children and lactating women.

The considered radioisotope study on the distribution of a radioactive drug in the tissues of the thyroid gland has a number of advantages and disadvantages.

Scintigraphic examination of the thyroid gland has a number of fairly significant advantages over other methods of radiation diagnostics, namely:

Low radiation activity - the minimum dose of radiation for the body.
High excretion of used radiopharmaceuticals - rapid excretion of radio substances from the body.
No pain syndrome.
The possibility of conducting a study without restrictions on the age group of the patient.
Characteristics of the hormonal activity of normal thyroid tissue.
The absence of secondary complications associated with the negative effects of radiopharmaceuticals on the body.
Conducting a survey using technetium.
The planned nature of the conduct.

Thyroid scintigraphy is a specialized and safe examination. However, this radiation technique has a number of disadvantages:

The high cost of the survey.
Possible allergic reactions that occur against the background of the use of iodinated drugs.
Variability of blood pressure indicators after scintigraphy.
Low resolution and blurry image of the organ.
Specific preparation for the study.
Inability to establish the goodness or malignancy of the node.

Among the endocrinological examinations of the thyroid gland, scintigraphy occupies a leading position.

Thyroid scintigraphy requires specific preparation for the procedure. First of all, it is more expedient to create conditions for a deficiency of iodine and thyroid hormones. To achieve this goal it is necessary:

Exclude from the diet foods containing trace elements.
Stop taking medications that may contain iodine or bromine.
Do not use hormonal preparations containing thyroxine for 30 days.
If it is necessary to use antiseptic preparations, preference should be given to antiseptics that do not contain iodine.
Do not perform procedures using contrast agents.

An examination involving the use of pertechnetate does not require special preparatory measures. This is due to the fact that the trace element is not involved in the process of hormone production by the gland.

Before the procedure, a consultation with an endocrinologist is necessary. Re-discuss the need for the procedure and the possibility of taking medications regularly used by the patient.

Thyroid scintigraphy is performed in radioisotope diagnostic laboratories. In a special room, a gamma camera is required. This installation has a complex mechanical structure, and includes:

radiation detectors;
photomultiplier;
lead devices for obtaining parallel beams of light rays;
device necessary for capturing the resulting image.

A gamma camera is a scanner necessary to record the concentration of a substance in the thyroid gland. The unit is indispensable for radionuclide diagnostics. Modern devices make it possible to obtain scintograms in an arbitrarily oriented plane, while changing the position of the patient is not required.

Scintigraphy order:

Introduction into the bloodstream of an isotopic substance (minimal doses of pertechnetate or iodine isotopes).
Acceptance by the patient of a horizontal position.
Placement of the patient in the gamma chamber.
Registration of radiation emitted by radiopharmaceuticals absorbed by the tissues of the gland.
A three-dimensional image of the gland is displayed on the monitor screen and recorded on the hard drive of the computer.
Taking pictures.
End of procedure.

The duration of the procedure is from 20-80 minutes. However, due to possible obstructive changes in the gland, the time of the procedure may vary.

During the procedure, a fixed dose of radiation is injected into the body in parallel with radioisotopes.

Complications after scintigraphy of the gland, based on the damaging effect on the body, were noted.

This fact indicates the safety of the study.

Radionuclide research allows you to get results within 30 minutes after the procedure. Under normal functioning and structure of the gland, segments of the organ accumulate the introduced isotopes evenly. The visual picture in the pictures is presented in the form of two dark symmetrical oval sections.

Segments of the thyroid gland, which are insufficiently saturated with a radiotracer, are reflected in the images as light areas. This fact indicates non-produced hormones, and are called "cold" foci. Such foci may indicate an inflammatory lesion of the gland, cysts, involution and proliferation of connective tissue with the presence of cicatricial changes.

Dark areas in the images are considered hormonally active, and are called "hot" foci. This picture is possible with nodular thyroid goiter.

Visualization of an increase in all segments of the organ, accompanied by a uniform cumulation of the radiotracer, means the presence of diffuse toxic goiter. This pathological change is characterized by increased cumulative function.

It is more expedient not to carry out independent interpretation of scintograms. The description of the obtained indicators is carried out by endocrinologists.

Today, endocrine pathologies are a medical and social problem. The study of the morphology and functional state of the endocrine secretion glands, the hormones produced by them, the features of their synthesis and effects on the body is extremely important. Radioisotope studies are widely used in endocrinology to diagnose pathological processes in the body.

According to medical statistics, thyroid scintigraphy in extremely rare cases causes secondary complications.

Yakutina Svetlana

Expert of the ProSosudi.ru project

The introduction of new diagnostic methods into practical medicine makes it possible to identify pathological changes in organs and tissues at the early stages of the disease. The method of simultaneous visualization of the anatomical structure and functions of the thyroid gland, carried out using a radioisotope pharmaceutical preparation and a device that allows recording emitted gamma rays, is called scintigraphy.

What is scintigraphy?

Experts explain the essence of the diagnostic technique by the fact that a special substance enters the body, each molecule of which conditionally consists of two components.

The first of these is a specific compound that is actively absorbed by a specific organ or tissue of the body (today, more than 20 radiopharmaceuticals are actively used in medical practice).
The second component is a radioactive isotope embedded in the carrier substance.

In the process of detecting radioactive radiation, both a scintillation gamma camera and a linear particle scanner are used. Both radiation counters can be used to obtain the test result. During operation, the computer captures and analyzes the data obtained and creates an image of the tissues in the area under study. In addition, special programs record the function of organs, displaying curves on a monitor and paper that characterize the processes of vital activity in general or a separate system of the body.

Kinds

Currently, the following types of scintigraphy are used to clarify the diagnosis:

static - carried out 30-60 minutes after the introduction of the radiopharmaceutical, demonstrates the accumulation of the isotope in the tissues during a series of images;
dynamic - performed within 60-120-180 minutes after the start of the study, allows you to study the distribution of the isotope in the organ (organ system) under study;
tomographic - is done using a single-photon emission computed tomography (SPECT), which allows you to simulate a three-dimensional image of the area under study;
planar - allows you to take pictures of the area under study in two mutually perpendicular projections.

Some patients incorrectly refer to this diagnostic procedure as a thyroid scan. Such a term exists, but literally scinting means the introduction into the body of a special drug that emits radioactive rays, and not the registration of its distribution in the body.

The result can be issued on disks and in the form of a medical report, which describes the changes found in the tissues and organs under study.

Advantages and disadvantages of the method

When recommending a radionuclide diagnosis to a patient, the doctor should tell the patient about the advantages and disadvantages of this method, and also warn about the need to follow certain rules.

The benefits of scintigraphy include:

Minimal harm to the patient's body. The amount of the injected isotope is selected in such a way as to obtain the clearest possible image of the tissue under study. In this case, the risk of side effects with thyroid scintigraphy is extremely low.
The possibility of simultaneous study of the structural features of the organ and its function.
Determination of the degree of damage (necessary for early diagnosis of metastases of malignant tumors).
If necessary, the study can be repeated an unlimited number of times to assess the dynamics of the disease.
No discomfort.
The study can be performed on patients of any age, but in children under 6–7 years of age, the diagnosis is difficult (the child cannot remain motionless for a long time, while any, even the smallest, movement distorts the result).

Disadvantages of radioisotope diagnostics include:

duration of the study - for high-quality diagnostics, it may take up to 8 hours;
image quality - the scintigram looks somewhat blurry;
the possibility of carrying out the procedure only in some clinics (most often, large oncology centers or research institutes are equipped with scintigraphy equipment);
the need to prepare the patient - in order to obtain a reliable result, the doctor may recommend abandoning certain drugs, disinfectants.

The duration of the study (the time spent under gamma-ray detectors) and the number of images (tomographic sections) do not affect the received radiation dose, it directly depends on the amount of radiopharmaceutical drug administered.

To prevent the accumulation of radiotracer in the body allows the introduction of isotopes with a short half-life. Thyroid scintigraphy is performed using:

pertechnetate (contains an isotope of technetium);
iodine.

Indications and contraindications

The procedure is for:

clarification of the nature of nodular formations (benign tumors, cancer);
identifying the causes of a decrease or increase in the functional activity of an organ;
control over the results of treatment.

However, you should be aware that:

Radioisotope diagnostics cannot be prescribed to women during pregnancy due to the probable ingress of a radioactive isotope through the placenta to the fetus, which can provoke malformations of intrauterine development.
Conducting a study in nursing mothers is possible only on reasonable grounds, while within 72 hours after the completion of the scintigraphy, the child must receive mixtures for artificial feeding or milk expressed by a woman before the procedure.
In people prone to allergic reactions, drugs to which hypersensitivity has been identified should not be used.
The general serious condition of the patient is a relative contraindication to the study due to the long duration of the diagnostic process.

Thyroid scintigraphy: preparation for the examination

When planning a scintigraphy, the patient should tell his doctor about all the drugs that he is prescribed and taking constantly.
There is no need to restrict the patient in taking water and food.
14 days before the study, any medications that affect the production of thyroid hormones are canceled.
It is necessary to abandon the use of an alcoholic solution of iodine, any medicines that include this trace element (including those prescribed by a gynecologist). Failure to comply with this rule will significantly change the metabolic processes in the body and the result of the study will be unreliable.
There are no special requirements for clothing and footwear, but it is worth picking up comfortable things in advance, since the procedure can take a significant amount of time (up to 8-10 hours), which will have to be carried out in the diagnostic center.
After completing the procedure, it is recommended to drink plenty of water, as this speeds up the elimination of the radioactive substance from the body.
It is necessary to warn the doctor about the x-ray or computed tomography of the area under study if such a diagnosis was carried out less than 4 days before the scintigraphy.

How is the procedure carried out

Thyroid scintigraphy is performed in specially equipped departments. You must arrive at the clinic in advance to complete the necessary medical documentation. Before starting the procedure, a radiopharmaceutical is injected into the body through a catheter installed in the cubital vein and a syringe.

Substances reach target organs at different time intervals, most often the first pictures are taken 5-10 minutes after the introduction of isotopes (the blood flow and the estimated size of the pathological focus are assessed). During the scintigraphy, the patient should lie motionless on the working table of the gamma camera, breathing should be calm, not very deep.

To increase the volume of blood in the vascular bed and better distribution of the diagnostic substance, the patient may be advised to drink several glasses of pure non-carbonated water in small portions.

Subsequent series of images allow you to study in detail how the drug is distributed in the tissues, whether there are areas of intense accumulation or, conversely, areas in which the marker accumulates very weakly. They are carried out 3-4, and in some cases 6 hours after the introduction of the isotope. Sometimes the doctor may recommend re-scanning the body after 24 hours from the start of the study, while evaluating how the injected substance is "washed out" from the pathological focus.

Scintigraphy - video

Possible side effects and harm

After the study is completed, the patient is released home, giving him a description of the scintigrams and pictures taken during the study. Radiation hygienists recommend showering immediately upon returning home, washing hair, and changing and laundering items worn during the study.

All auxiliary materials (bandages, plasters, tampons) must be thrown away at the clinic in special containers for materials that have come into contact with isotopes.

The likelihood of exposure of people around after scintigraphy is negligible. To prevent re-entry of radiation into the body, it is necessary to carefully observe the rules of personal hygiene (washing hands after each visit to the toilet).

Since isotopes with a short half-life are used today for the procedure, the procedure does not cause any harm to human health, provided there are no contraindications. However, in isolated cases it is possible:

the development of an allergic reaction;
temporary change in blood pressure;
nausea or vomiting;
frequent urge to urinate, which passes quickly.

Deciphering the results

The main reason for scintigraphy is to determine the nature of the nodes formed in the thyroid gland. Depending on their coloration, the obtained images are diagnosed with the presence of:

Cold nodes that do not accumulate an isotope. They are characteristic of colloid goiter or tumor diseases.
Hot, actively accumulating radioactive substances. A similar picture is typical for diseases accompanied by impaired functioning of the gland, which may be a sign of multinodular toxic goiter and toxic adenoma.

If the isotope gradually or progressively accumulates in the thyroid gland, this indicates the development of diffuse toxic goiter. Weak absorption of the substance by the tissues of the gland may indicate hypothyroidism.

The image obtained during the study shows cold and hot nodes