Thyroid scintigraphy
Content:
- What is scintigraphy?
- How can the results be measured?
- How is the research going?
- Side effects
- Preparation for scintigraphy
What is a thyroid scintigraphy?
Scintigraphy is a check of the structure and functioning of the thyroid gland by introducing a contrast solution into a vein or by swallowing a capsule with further monitoring of its radiation. Such an examination is not carried out for everyone, because he has clear indications.
- We are talking about the following cases:
- Abnormal placement of the gland;
- Numerous (over six in both lobes) formations of the nodular type;
- Thyrotoxicosis and its differential diagnosis;
- Radiation therapy or emergencies.
All other indications should be considered relative with the possibility of using another examination method.
How can scintigraphy results be assessed?
In the overwhelming majority of cases, thyroid scintigraphy is performed in order to establish the presence of nodular formations, as well as to determine the degree of their activity in functional terms. This activity refers to whether they are able to produce hormones on their own. As a result, nodes are identified that are conventionally divided into "cold" and "hot" and have a certain color.
The first type of nodes is not prone to accumulation of a radioactive isotope. Also, such a study involves the use of technetium 99. This explains the high cost of endocrine gland scintigraphy. The presented survey method is completely safe. So, the only 100% contraindication should be considered any of the stages of pregnancy.
Thus, "cold" nodes are recognized as characteristic of nodular colloid goiter or diseases involving the formation of tumors. The presence of a "hot" node is explained by the constant accumulation of the isotope. In most cases, this occurs when some function is abnormal. For example, multinodular toxic goiter or toxic adenoma.
The progressive and increasing uptake of the isotope is direct evidence of a disease such as diffuse toxic goiter. Weak absorption algorithm suggests hypothyroidism.
How is the 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 examined organ. Then the received data are processed using a computer. As a result, the doctor receives all the information he needs. It is obvious that the implementation of scintigraphic examinations presupposes a high-quality and fairly wide equipment base. The work of specialists of the corresponding specialization will be no less necessary.
The dosages of the introduced isotope are completely harmless, because this component is extremely quickly degraded and eliminated. In the presented situation, the ratio is much less than with the usual examination using an X-ray. In most cases, there are no allergic reactions to the injected solution.
Preparation directly for thyroid scintigraphy takes no more than half an hour. It is during this period of time that the radiological pharmaceutical will have time to accumulate in the organ in the required ratio. The examination itself will take no more than 20 minutes.
There are also special medical requirements, which are to stop using a wide variety of drugs. So, 30 days before the 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 performed. While medications can accumulate in the tissues of the thyroid gland. In this regard, the results of the study may be of little informative or implausible.
In any case, it is the endocrinologist who sent the patient for this examination who must explain in detail exactly where the endocrine gland scintigraphy is done. It is his responsibility to tell you about the basic standards of preparation for this survey. The endocrinologist should also discuss future treatment tactics and substitution of essential drugs.
Scintigraphy is an expensive examination method that requires highly qualified medical personnel. Along with this, access to a medical nuclear reactor is needed, which will make it possible to obtain isotopes if necessary. Considering the half-life of the material, which is six hours, it can be quite difficult to deliver the product 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 imperative to take into account the safety requirements and, taking into account their potential danger, the protection of facilities with materials of radioactive origin.
Side effects
This method of examination is radiation-safe. Side effects after the procedure for examining the endocrine gland in 99% of cases are directly related to individual intolerance or allergic reactions.
Side effects include:
- Allergic reactions to radioactive components;
- A temporary increase or decrease in blood pressure indicators;
- Constant urge to urinate, and nausea or vomiting, which pass quickly.
After performing the procedure using iodine, the patient in rare cases may experience such manifestations as a blush on the face or fever. If the patient experiences persistent dizziness, weakness or itching on the skin after the injection, then it is necessary to inform your doctor or any of the medical personnel about this as soon as possible.
In general, the radiation received by the patient during the examination is so low that the scintigraphy can be performed many times. With a total study of the endocrine gland, it is permissible to carry out it twice a month.
Preparation for thyroid scintigraphy
A prerequisite for a scintigraphic examination is 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. It is an anti-arrhythmia drug. One to two months before scintigraphy, it is recommended to avoid prescribing X-ray contrast drugs and those that contain iodine.
Three to four weeks before the study, it is recommended to stop the use of thyroid hormones, and also to avoid the use of iodine-based antiseptics. We are talking about Lugol's solution or betadine.
One week before the scintigraphy, it is undesirable to use such means as:
- Propylthiouracil;
- Mercazolil;
- Sulfanilamide antibiotics (streptocid, biseptol);
- Aspirin;
- Nitrates (nitroglycerin, monosan, cardiket, nitrosorbide).
Failure to comply with these rules can provoke distortion of the survey results. This is due to a decrease in the area of uptake of a radiological pharmaceutical by cells.
It should be noted that scintigraphic examination involving the use of 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 may be required using an iodine-based radiological pharmaceutical.
Thus, endocrine gland scintigraphy 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 on the part of a specialist. Subject to all the above conditions and recommendations, scintigraphy guarantees a 100% accurate result.
The author of the article: Kuzmina Vera Valerievna | Endocrinologist, nutritionist
Education: Diploma of the Russian State Medical University named after NI Pirogov with a degree in General Medicine (2004). Residency at Moscow State University of Medicine and Dentistry, diploma in Endocrinology (2006).
