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X-ray of the thyroid gland
Last reviewed: 19.11.2021
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Recognition of diseases of the endocrine glands is one of the brightest pages of radiation diagnostics. With the help of radial methods, the doctor determines changes in the structure of the gland and focal formations in it. Moreover, he can detect and quantify the dysfunction of each gland and the "governing organs" of the hormonal hierarchy - the hypothalamus and pituitary gland. However, we must not forget that the main indicator - the level of hormones in the peripheral blood - does not always and not fully reflect the patient's condition, since it depends not only on the function of the endocrine glands, but also on other regulatory mechanisms. In this regard, when evaluating the results of radiation studies, it is necessary to take into account the anamnestic data and the clinical picture of the disease.
Radiation anatomy of the thyroid gland
The thyroid gland is located in the anterior region of the neck in front of the trachea. It has a horseshoe shape with concavity facing posteriorly, and consists of two unequal parts, which are connected by an isthmus. Sometimes there are additional thyroid glands (on the neck, in the root of the tongue, in the chest cavity), which can be detected with the help of radiation methods, especially in scintigraphy.
X-ray anatomy of the thyroid gland
Radiation examination of the physiology of the thyroid gland
The state of iodine metabolism and thyroid function is assessed by radionuclide studies. As is known, the thyroid gland performs three main functions:
- seizure of iodides from the blood;
- synthesis of iodine-containing thyroid hormones;
- the release of these hormones into the blood.
X-ray examination of thyroid physiology
Clinical and radiological syndromes and diagnostic programs for diseases of the thyroid gland
In order to conduct rational treatment, it is necessary to determine the morphological changes in the thyroid gland and the level of endocrine function of all glands that regulate iodine metabolism in the body.
In case of impossibility of carrying out radioimmunological analysis, and also if necessary to establish the state of intra-thyroid iodine exchange, radiometry of the thyroid gland is performed.
Diffuse goiter. There is a diffuse increase in the entire thyroid gland in the absence of individual palpable nodes and diffuse-nodular goitre when one or more nodes develop in the enlarged organ. In both forms, the gland function can be normal, strengthened, or weakened.
Sometimes the thyroid gland is located behind the breastbone ("squamous goiter"). The shadow of this goiter appears on radiographs and especially on the tomograms. Scintigrams allow us to distinguish it from tumor formation in the mediastinum.
Toxic nodular goiter. With nodular lesions of the thyroid gland, it is advisable to start the study with sonography. Ultrasound scanning can confirm the presence of nodes in the gland, establish their macromorphological structure, distinguish them from cysts. The next stage of delineation of nodal formations is scintigraphy. Most of the nodal formations, with the exception of toxic adenoma, give on the scintigraph a defect accumulating RFP - a "cold" focus.
Benign nodal education. In the thyroid gland there are various benign forms of nature: cysts, adenomas, nodes with certain forms of colloid goiter, areas of limited thyroiditis, scarring fields. All of them on the scintigrams determine the area in which the RFP does not accumulate or accumulates very weakly, i.e. A "cold" node. Based on the results of radionuclide research, it is difficult to establish its origin, and sometimes it is impossible. In this case, the diagnosis is assisted by clinical data, sonography and biopsy results.
By the nature of the structure, benign lesions are divided into solid, cystic and mixed. A solid node consists of a dense tissue, the cystic is a cavity with liquid contents, and a mixed one includes both dense tissue and cysts.
Sonograms allow you to immediately identify all cystic formations. The cyst is defined as a round or oval body with smooth contours and has a uniform echo-negative effect. The follicular adenoma looks like the formation of a regular rounded form of reduced echogenicity with some structural heterogeneity. The outlines of the adenoma are usually even. The denser areas in it are determined by increased echogenicity; in such cases, a diminished band around the echogen, due to the peri-node edema of the thyroid tissue, can be seen. "Cold" focus with limited thyroiditis gives a site of low echogenicity with blurred outlines and small additional structures inside.
Malignant volumetric formation. A cancer node in the thyroid gland is usually single. On scintigrams it usually appears as a "cold" hearth. The ultrasound picture is not easy for interpretation, as it varies depending on the structure of the tumor. Most often on sonograms you see a node of low echomolarity with fairly clear, but uneven contours. However, there are tumors with increased echogenicity. The image of the node is not uniform: on its background there are areas of different echogenicity. There is no echo-negative rim around the tumor. Instead, very small calcifications in the form of short lines or foci are often visible around the periphery of the node.
Hypothyroidism. There are four forms of hypothyroidism: primary, secondary, tertiary, iodine deficiency. With primary hypothyroidism, hormone formation in the thyroid gland itself was disrupted, with the thyrotropic function of the pituitary gland reduced. Tertiary hypothyroidism is caused by oppression of the hypothalamus. Finally, iodine deficiency hypothyroidism develops with insufficient iodine content in food and water.
Parathyroid adenoma
Parathyroid glands control all calcium metabolism in the body. Hyperfunction of one or both glands leads to primary hyperparathyroidism. The level of parathyroid hormone in the blood is determined by the radioimmune method. This is a very sensitive reaction, which makes it possible to establish hyperparathyroidism before the appearance of changes in the bones, detected by X-ray patterns. In approximately 80% of cases, hyperparathyroidism is associated with the development of a single parathyroid adenoma. Secondary hyperparathyroidism is usually explained by hyperplasia of both glands in chronic kidney diseases.