Ultrasound examination (ultrasound) of the parathyroid glands

The assertion that the general condition of a person directly depends on the normal functioning of all organs and systems in the body does not require proof. The leading role in the body is played by the endocrine system, and in violation of the function of the endocrine glands, dysfunction of virtually all internal organs develops. That is why it is very important to seek qualified help at the first clinical symptoms and complaints. The parathyroid (parathyroid) glands play a very important and vital role in human health. They produce parathyroid hormone, which controls calcium homeostasis in the body, regulates calcium-phosphorus metabolism, which includes normal bone formation, maintenance of bone and tooth strength, contraction of skeletal muscle of cardiomyocytes and smooth muscles, nerve impulse transmission, endo- and exocrine secretion. , cell division, regulation of glycogenolysis and gluconeogenesis. Many pathological conditions are caused by a lack or excess of the production of this hormone, which causes a violation of the structure of bone tissues and neuromuscular excitations. One of the methods for diagnosing the condition of the parathyroid glands is ultrasound (ultrasound).

Ultrasound diagnostics has been successfully used in clinical practice since the 20s. The study is based on the fixation of the reflected ultrasonic signal for visualization of the organ under study. This diagnostic evaluates the localization, shape, structure, size of organs using a non-invasive method. When examining the parathyroid glands, the ultrasound doctor examines longitudinal and transverse images from the bifurcation of the carotid artery as the upper border and to the midline of the chest as the lower border.

Anatomy of the parathyroid glands

These organs have the most unique anatomy. The parathyroid glands are endocrine glands located in the visceral space of the neck. The parathyroid organs are usually found on the back of the thyroid gland (para means “around”, therefore “around the thyroid gland”). Their anatomical location depends on the intrauterine anlage. They can be located in the neck, from just below the jaw all the way to the chest next to the heart, but in 80% of cases, the parathyroid glands are located just behind the thyroid gland.

In most cases, a person has two pairs of parathyroid glands, lower and upper, but in 13% there are more than four glands, cases are described when their number even reached twelve. The gland is the size of a grain of rice (half a pea), oval or bean-shaped. With a developing adenoma, the size of the gland can increase to the size of an almond. Knowing this peculiar anatomy, one can easily understand why the experience of the surgeon is so important for a good result in operations. It usually measures 6 x 4 x 2 mm and weighs about 40-60 mg.

The parathyroid glands are very small and, at their normal size, are usually not identified by ultrasonography (ultrasound). Therefore, the visualization of the parathyroid glands during ultrasound is alarming for the presence of pathological formations. The superior parathyroid glands are more often located behind the superior thyroid lobes with little anatomical variation. The lower ones have a more variable location due to their embryological relationship to the thymus. The inferior parathyroid glands are located along the lateral inferior thyroid in 50% of the population and 1 cm below the lower lobe in 15% of the population. They can also be located somewhere between the angle of the mandible and the upper mediastinum. Most people have four parathyroid glands, although in 13% of the population they are most often found in the thymus.

Indications for an ultrasound

The most common complaints for suspected parathyroid disease are: the presence of prolonged pain in the bones and muscles, decreased bone density, unreasonable weight loss, fatigue, weakness, decreased performance, frequent increases in blood pressure, numbness of the upper and lower extremities, seizures , apathy and depression, headaches, increased fragility of nails and severe hair loss. Often there are cases of spasms of the facial nerves, throat or limbs, the development of eye diseases, in particular cataracts. Indications for ultrasound examination are conditions for:

• suspicion of the presence of tumor neoplasms;
• elevated levels of calcium and parathyroid hormone in human blood and signs of hypercalcemia (shortening of the QT interval on the ECG);
• osteoporosis of unknown etiology, pathological bone fractures without injury;
• in the presence of a history of urolithiasis, recurrent staghorn nephrolithiasis and re-formation of stones after surgery;
• detection of calcifications in various tissues and internal organs;
• control of the therapy for hyperparathyroidism and before surgical interventions on the parathyroid glands.

Ultrasound examination will help to assess not only the size, structure, but also the possible nature of pathologies, to assess the blood supply to the parathyroid glands.

The technique of ultrasound of the parathyroid glands

This diagnostic method does not require special training, and there are no contraindications for its implementation. The very procedure of ultrasound of the parathyroid glands is painless, and takes about twenty minutes.

The patient is placed on a special couch in the supine position. The doctor may place a small roll under the patient’s neck, tilting the head back to allow better access and visualization of the glands. The specialist applies a special gel on the neck area, which is called a media gel, and ensures that the sensor contacts the skin surface in the area of ​​the organ being examined, in particular, the anterior and lateral surfaces of the neck.

When applying the gel, the patient may feel a certain coldness and experience some discomfort when holding the neck during the study, but this cannot be discomfort from the transducer and the generated sound waves. The patient can breathe and swallow comfortably during the examination.

Parathyroid glands should normally not be detected, even when using the highest resolution. But with an increase in their size and when there is a pathology of the thyroid gland, they become available for visualization on ultrasound. This is not easy enough, so it is important to trust the study only to an experienced and qualified doctor. The study is carried out under standard scanning modes, which allow the doctor to accurately and highly informatively assess the size, volume, structure, nature of pathologies, if any, and check the location of the lymph nodes.

Common pathologies of the parathyroid glands

In medicine, several of the most common diseases of the parathyroid glands are distinguished – primary, secondary and tertiary hyperparathyroidism. Primary is most often associated with the detection of adenomas in patients – benign tumors. They can be either single or multiple with a delicate capsule and structure. Secondary hyperparathyroidism develops against the background of vitamin D deficiency and in the presence of chronic renal failure in a patient. Vitamin deficiency can be corrected with medication, and chronic kidney failure is treated with kidney replacement therapy with dialysis procedures or a donor kidney transplant. Tertiary hyperparathyroidism is the most severe of all the above diseases. Since it occurs against the background of long-term renal failure and can only be corrected by surgery.

The echogenicity of the parathyroid glands on ultrasound is slightly higher than that of the thyroid tissue. Often, calcifications can be found in the projection. With hypoparathyroidism, aplasia may be detected. But this is a rather rare pathology that develops against the background of an anomaly in the development of other organs. With hypoplasia that occurs in early childhood, it is possible to reduce the parathyroid gland with preserved echogenicity. There may also be congenital hyperplasia of the parathyroid glands, which causes congenital hyperparathyroidism. During the development of acquired hyperplasia, as a rule, one of the glands increases.

Cysts rarely develop in the parathyroid glands. Most often after large hemorrhages or tumor decays. They have a thin wall and a pronounced lack of echogenicity. Sizes from one to ten centimeters in diameter.

Thus, ultrasound examination of the parathyroid glands makes it possible to detect diseases at an early stage with the possibility of subsequent targeted diagnosis and the choice of a treatment method.

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