In medicine, different methods are used to study the state and functionality of organs. Thyroid scintigraphy helps to study its structure and function. A contrast medium is injected into the vein, or a capsule with a radiopharmaceutical is swallowed by the patient in order to record the radiation. The gamma camera scans the front of the neck. The rules of the event are described in the article.
general information
Thyroid scintigraphy is a procedure based on the study of the work of this body to capture, accumulate and excrete iodine. The thyroid gland, in comparison with other organs, is able to consume a large amount of this microelement, necessary for the production of hormones. T
To perform thyroid scintigraphy, radioactive iodine 131 or the technetium isotope must be introduced into the body. These components are absorbed and then transferred to body tissues. In the thyroid gland, these substances accumulate faster.
Then, the front of the neck is scanned in the gamma camera (a special counter is used for this). The information obtained is transferred to a computer monitor, where it is analyzed and displayed in the form of a mathematical and three-dimensional model. Scintigraphy does not involve puncture of a vein, iodine is administered orally. Intravenous administration is sometimes required.
Often, a study is performed after the thyroid gland has been removed. Isotopes are not able to participate in the synthesis of thyroid hormones. They are excreted from the body by the kidneys, which is why the side effects are minimal. Thyroid scintigraphy is needed to establish the exact location of the thyroid gland, and thanks to the radioisotopes, the doctor identifies their places of accumulation and intensity. If there are malignant neoplasms in the organ, then the examination allows you to establish the localization of metastases.
When is the procedure performed?
Thyroid scintigraphy with technetium is performed when:
- anatomically incorrect arrangement of the organ;
- abnormalities of the development, structure of the gland;
- differential diagnosis of thyrotoxicosis;
- risk of malignancy;
- the presence of non-functional nodes;
- a violation of calcium metabolism, which appears with dysfunctions;
- diffuse toxic goiter;
- Plummer's syndrome or thyrotoxic adenoma;
- pituitary adenoma;
- de Kerven's disease;
- autoimmune thyroiditis;
- autoimmune ophthalmopathy;
- vegetovascular dystonia.
Typically, a procedure is prescribed if there is a risk of diffuse toxic goiter. With it, it will be possible to identify the features of the body.
Contraindications
The procedure cannot be performed when:
- pregnancy
- intolerance to a radioactive drug.
Of the relative contraindications, breastfeeding is distinguished. Women need to refrain from feeding the baby for the period of complete removal of the drug from the body (approximately 48 hours).
Location
Where to do thyroid scintigraphy? The procedure is carried out in large diagnostic centers, where trained specialists practice. These centers have a medical nuclear reactor that synthesizes isotopes. The procedure is expensive and high-tech. The event is based on the direction of the endocrinologist.
Thyroid scintigraphy in Moscow is performed in many large centers. For example, you can go to the clinic of functional disorders at Gabrichevsky. Thyroid scintigraphy in St. Petersburg is performed at the Medsi International Clinic and many other centers. During the procedure, safety measures associated with the use of radioactive materials are observed. These objects are protected on the basis of applicable law.
Preparatory Activities
What is the preparation for thyroid scintigraphy? Before the event, for a month you can not take funds with iodine. An exception are drugs prescribed for the treatment of ailments. For 3 months, studies using radiopaque drugs cannot be performed.
A week before the procedure, you must stop taking:
- propylthiouracil;
- “Streptocide”, “Biseptol” and other sulfa drugs;
- merkazolil;
- acetylsalicylic acid;
- nitroglycerin and other nitrates.
Do not eat before such a study. The patient uses the iodine isotope preparation (or technetium). The next day, a scan is performed. Isotope dosage is considered safe for health.
Thyroid scintigraphy can be done with the technetium-99 isotope. In this situation, special preparation for the procedure is not needed, the substance does not participate in the production of thyroid hormones. In some cases, an additional examination with an iodine isotope is necessary.
How is it done?
The procedure is carried out using radiopharmaceuticals. MIBI and Technetril are considered labeled isotopes of technetium-99. Pertechnetate is a solution of pure radioactive technetium. Its introduction is carried out intravenously. Radioactive iodine 123 is used in the form of tablets for oral administration.
After taking the drug with technetium or iodine, the patient visits a diagnostic laboratory. There, scanning and fixing with special devices of gamma radiation are carried out. To do this, he lies on a couch on his back. Using a device, a specialist measures each thyroid gland node, and the image of the examined sites is broadcast on a monitor.
In order to identify oncology as early as possible, the scenography is performed with a gamma camera that captures the radiation that comes from the sites being examined. The camera consists of:
- a detector;
- photoelectronic multiplier;
- lead collimators;
- a computer with special equipment that captures an image from information on the distribution of a radioisotope.
During the procedure, a person is in the cell for no more than half an hour. Upon completion, the patient can leave the institution, since no more activities are needed. Since isotopic agents are removed from the body throughout the day, after such a diagnosis, additional drugs should not be taken, diet and physical activity should be limited.
results
Scintigraphy is performed to detect nodular formations in the thyroid gland and determine the level of their activity. The doctor determines the activity of the formation of hormones. The nodes are conditionally divided into cold and hot. The former are not able to accumulate radioactive iodine. This is observed with nodular colloid goiter or tumor pathologies. With hot nodes, the isotope is able to accumulate constantly. This occurs with toxic goiter or adenoma.
Normally, a radioactive agent is able to accumulate evenly in the gland. If there is a pathology, the procedure shows the following results:
- The increased intensity of drug accumulation is evidence of diffuse toxic goiter.
- If the intensity of accumulation is weakened, then this is hypothyroidism.
- The unevenness of the presence of an isotope is considered confirmation of chronic autoimmune thyroiditis.
- The presence of a single hot node indicates toxic adenoma.
- Uneven nodes confirm thyroid cancer.
- If there is an isotope in the remaining organs, we can talk about cancer metastases.
Probable complications
After performing the procedure using iodine, a person may have a blush on his face and fever. Other side effects from the use of technetium 99 were not found. In general, the procedure is considered safe and reliable. The dose of radionuclides is low, and there is no danger to humans. The agent is removed from the body in a short time. Experts advise on the first day after the event to exclude contact with infants and pregnant women.
Another possible side effect is an allergy to iodine, which is part of the drug used. If a person feels dizzy, weak, itchy on the skin after an injection, then it is necessary to inform the medical staff about this. Irradiation received during the study is considered insignificant, so the procedure can be performed repeatedly. But still, it should be carried out only after her appointment as a specialist.
Pros of the procedure
According to reviews, thyroid scintigraphy allows you to establish an accurate diagnosis. Based on the results of this event, the doctor will be able to prescribe the appropriate treatment. This procedure has other advantages:
- No harm is done, only in rare cases is an allergy observed.
- A small portion of gamma radiation allows you to perform an examination every month.
- The procedure allows you to evaluate not only the structural features of the gland, but also its function.
- Scintigraphy determines the level of damage to the thyroid gland.
- Complex preparation is not needed, the patient needs to limit the use of drugs with iodine and to discontinue medications that negatively affect the examination effect.
- Diagnosis does not cause pain.
- After scintigraphy, additional medication and recovery measures are not required.
Minuses
In medical practice, this procedure is one of the most sought after. With it, it will be possible to accurately determine the type of pathology. But there are still disadvantages. Of the minuses emit:
- The image is not sharp enough in comparison with computed tomography or magnetic resonance imaging.
- The duration of the procedure.
- Contact with radioactive components.
- High price.
- Inaccessibility, as the event takes place only in some large cities.
Scintigraphy allows you to study the structure and function of the thyroid gland, to identify existing pathologies. Based on this, the doctor prescribes an effective treatment.