Densitometry - what is it? Densitometry of bones and spine: indications and prices

The density of bone tissue reflects the level of concentration of inorganic compounds (for example, calcium). Simply put, this parameter indicates the strength of the elements.

General information

With the passage of the years, each person decreases the volume of bones. Elements become thinner, and their structure is more porous. This is due to the fact that the process of formation of bone tissue proceeds more slowly than destruction, catabolism predominates over anabolism. With age, the leaching of inorganic compounds from the elements is enhanced. This, in turn, reduces the strength of bones, increasing the likelihood of fractures. So, osteopenia gradually leads to the appearance of osteoporosis. The denser the bone tissue initially , the more time it will take to destroy it. To strengthen effective exercise (classes on exercise machines and walking) and calcium preparations. The most modern include such means as "Actonel", "Fomasaks", "Miakaltsik". Women in the period of menopause are prescribed hormonal (replacement) therapy. It helps to slow catabolism.

Risk factors

The development of osteoporosis is facilitated by several factors.

• Age. Usually, by the age of 30, the maximum strength and density of bone tissue is achieved. After this, a gradual decrease occurs.
• The gender factor. Women who are older than 50 years are more predisposed to the development of destruction. They are four times more likely than men to be affected by osteoporosis.
• Structure of the bone and body weight. Large women are less predisposed to osteoporosis than thin and thin. A similar situation with astenichnymi men.
• Acceptance of a number of medications. For example, with prolonged use of steroid drugs (for example, the drug "Prednisolone"), the negative effect on the state of bone tissue increases. This, in turn, increases the likelihood of osteoporosis.
• Presence of bone fractures in history.
• Postoperative condition after removal of ovaries.
• Family history. One of the most significant factors in the development of bone pathology is heredity. In the event that relatives (grandfathers, parents, grandmothers) had signs of osteoporosis (for example, a fracture of the femur with a slight fall), the risk of developing it is high enough.
• Excessive reception of alcohol.
• The presence of somatic pathology, accompanied by excessive excretion of calcium from bone tissue (eg hypothyroidism).
• Hypodinamy.
• Initially, thin bones.
• Food with a low content of vitamin D and calcium.
• Early onset of menopause.

Measurement of tissue density: methods

There are different ways of doing research. One of the most popular methods is densitometry. What is this research? This procedure is carried out using special modern equipment. In the process of research, the patient lies on the back on the table with the lower legs lowered or straightened legs. Next, consider what kind of densitometry can be, what it is, in which cases it is recommended.

Dual Energy X-ray Diagnostics

This is one of the ways densitometry can be performed. What is a dual-energy x-ray? This method is considered the most accurate in the measurement of tissues. In this case, two different rays are used. This method performs densitometry of the spine and thigh. The thicker the tissue, the more difficult it is to pass through the x-ray. When summing and comparing the results of absorption of two effects, the specialist has the opportunity to more accurately establish a decrease in tissue density. With the help of densitometry it is possible to measure from 2% loss of its mass per year. Densitometry lasts (which is described above) for a short period of time. The dose of irradiation during the study is very low.

Peripheral bone densitometry

The information is obtained in the same manner as described above. Densitometry, the price of which will be indicated below, allows you to examine the density of tissue in the leg and arm - in the region of the heel and wrist. However, it is extremely difficult to make measurements in other areas. In particular, this applies to the spine and upper part of the lower limb, where fractures most often occur. In the study in this case, very low doses of radiation are used. Peripheral densitometers are portable devices. They can be used in a regular medical office. It should be noted that the informativeness of this method of investigation is not very high. Peripheral bone densitometry is important for screening studies, as well as for monitoring the effectiveness of osteoporosis treatment.

Two-photon method

In this case, radioactive isotopes are used in the study. The method allows to estimate the density of tissue in the spine and thigh. Low dosages of radiation are also used during the procedure. It should be noted that the two-photon densitometry of the spine and the thigh area requires a longer period to obtain results.

Quantitative CT

This is one of the types of tomography, in which X-rays are used to visualize the structure of the bone and the true picture of tissue state in bulk. However, this method is not used in practice as often as, for example, peripheral densitometry of bones (what is it, described above). This is due to the large radiation burden on the body.

Ultrasound densitometry

This method of investigation is based on measuring the speed of the wave with which it propagates along the surface of the tissue. In addition, broadband scattering in the surveyed area is assessed. Thanks to this procedure, a specialist can evaluate not only the density, but also the stiffness and elasticity of the tissue. The information content of this study is significantly inferior to those in which X-rays are used.

Indications

Densitometry is recommended for the following categories of citizens.

• Persons who have more than 2 risk factors for osteoporosis.
• Women in the period of menopause. The examination should be carried out both with artificial (after removal of the ovaries) and in the natural state.
• Men after 50 years.
• Patients who have osteoporosis with an X-ray.
• Persons from 40 years who have suffered one or more fractures (in case of an accident, fall, injuries at work or sports).
• Patients with endocrine and rheumatic pathologies.
• Patients with scoliosis, intervertebral hernia, osteochondrosis or spinal injuries.
• Persons receiving treatment for osteoporosis (to determine the effectiveness).
• Women who have used hormonal contraceptives for a long time.
• People with small growth (up to one and a half meters), not due to heredity.
• Persons whose mass index does not reach 18.5 units.

Contraindications

Since the patient undergoes X-ray exposure during the procedure, densitometry (even in minor dosages) is not recommended for pregnant women. This is due to the high probability of a negative effect of radiation on the fetus. Among other reasons for which the study may be contraindicated, it should be noted:

• The presence of metal implants used in reconstructive surgery;
• Arthritis of the spine;
• Recent injuries, fractures.

Densitometry is not recommended for 10 days after the X-ray examination using barium contrast.

Preparation

Densitometry, the price of which varies within 2000 rubles, is a painless procedure. Before it is performed, there is no need to specially prepare in any way. Typically, one procedure is sufficient to measure tissue density.

The course of the study

Before performing the procedure, the patient is asked to remove all ornaments, objects with metal elements. The study does not cause a person discomfort, is non-invasive. Densitometry does not cause negative consequences. Its duration is 5-20 minutes. The duration depends on the volume of the study. During the procedure, X-ray scanning of the skeletal areas is performed. Measurement of the radiation absorption level is recorded by a special sensor. Based on this information, a graph is drawn up. The measurement of the projected area of the site and the concentration of mineral compounds are being carried out. Based on these indicators, tissue density is calculated .

Result

The values obtained at the end of the measurement are expressed by the indices T and Z. The first T-scale compares the density of the patient's bone tissue with the control parameters of healthy people of 30 years. The Z scale allows comparison with the average parameters in the population in accordance with race, gender and age. Normally, the density should be at least 1 standard deviation. Density in the range from -1 to -2.5 on the T-scale is regarded as osteopenia, that is, a state that precedes the appearance of osteoporosis with a moderate risk of fractures. When carrying out the diagnostic, the heterogeneity of tissue density at different sites is taken into account.

Finally

Today, in the diagnosis of osteoporosis, densitometry has become the most popular research method. Where to make the procedure? This research is carried out practically in every city of the country, in many and narrowly specialized clinics. If necessary, repeated procedures are performed to help control the state of mineral metabolism. Their periodicity is chosen for each patient individually. This takes into account the characteristics of the profession, age, anamnesis.