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When diagnosing osteoporosis, which means the process of lowering bone mineral density, specialists need to make the correct diagnosis so that the prescribed treatment will bear fruit. For this purpose, as well as to check the course of treatment and its feasibility in general, modern medicine uses densitometry. It is a non-invasive technique for determining bone mineral density in quantitative terms, which is a mandatory component of the diagnosis and treatment of osteoporosis.
Varieties of densitometry
Painless for the patient, densitometry can be performed in many private and public clinics. At the moment, there are 2 main types of manipulation – using ultrasound and X-ray method.
Ultrasonic densitometry can be performed using a portable densitometer, which captures and displays data on the speed of movement of ultrasonic waves through the bone tissue using a sensor on a personal computer screen. The most common object for ultrasonic densitometry is the calcaneus. This diagnostic method belongs to non-radiation therapeutic methods and can be used even in pregnant and lactating women an unlimited number of times.
The main advantages of this type of diagnostics are the speed of the procedure, its complete painlessness and non-toxicity. In addition, ultrasonic densitometry is quite affordable for most patients in material terms. Its disadvantages include only the fact that this technique can only be used for the initial diagnosis of osteoporosis, and in the course of treatment or to clarify the data on the disease, it is necessary to use a more specific type of densitometry – x-ray.
The X-ray type of densitometry is the most accurate when compared with the ultrasound method. The essence of X-ray densitometry lies in the fact that when X-rays pass through the bone tissue, they are weakened to a certain extent. The degree of this weakening is fixed by a special device, which subsequently, according to certain algorithms, evaluates the presence of minerals encountered in the path of the X-ray beam in the bone.
X-ray densitometry is performed on the lumbar spine, in the upper femur, the wrist joint, as well as on the entire skeleton of the human body, if necessary and for certain indications. Due to the use of an X-ray beam, this type of densitometry is contraindicated in some categories of patients, for example, pregnant or lactating women. Devices for this study can only be located in specially equipped rooms. X-ray densitometry is carried out in specialized clinics where there is the necessary equipment. The cost of such a procedure is much higher than ultrasonic densitometry, which does not always allow diagnostics even in cases of urgent need.
If the necessary equipment is available in the medical facility, the examination is carried out according to the CHI, i.e. free of charge.
Indications and contraindications
The procedure of densitometry is necessary for patients who have:
- female age after 40 years, menopause, male age after 60 years;
- diseases of the parathyroid glands;
- in case of adnexectomy (removal of the ovaries);
- even a one-time fracture of any bone due to minor injuries;
- age over 30 years with a history of the patient’s close relatives diagnosed with osteoporosis;
- taking medications that promote calcium leaching (glucocorticoids, anticoagulants, oral contraceptives, diuretics or psychotropic drugs, anticonvulsants, tranquilizers, etc.), as well as alcohol abuse and smoking;
- sedentary lifestyle;
- small body weight and height;
- periodic outbreaks of unbalanced nutrition – therapeutic starvation, diets, lack of a normal full-fledged diet;
- regular physical overstrain – hard physical labor, active sports loads, etc.
There are no contraindications for the ultrasound method for diagnosing osteoporosis. X-ray densitometry, as mentioned earlier, is contraindicated for frequent use, as well as in cases of pregnancy or breastfeeding.
The essence of the diagnostic process
A densitometric study does not imply any specific preparation for its passage. In the primary diagnosis of osteoporosis on the eve of the study, it is necessary to exclude the use of drugs containing calcium, as well as other substances that retain calcium in human blood. In terms of special clothing, there are also no recommendations, the only thing worth considering is the absence of metal parts in clothes and jewelry. If they are present, the diagnosis may not be correct, so you should worry about this in advance.
Despite the complete safety of ultrasound densitometry, a woman should warn the doctor about pregnancy. This is necessary to exclude an X-ray examination, as well as the choice of therapy, in order to prevent the negative impact of the procedure on the fetus and the body of the expectant mother.
With ultrasound densitometry, the examination is carried out using a special monoblock apparatus. This device has a small niche where the heel, finger or forearm of the patient is placed in order to determine the speed of ultrasound through the bone tissue with the device. Within 2-3 minutes, information about this process is read by a densitometer and displayed on a computer monitor connected to a portable device.
A completely different examination procedure is used in the X-ray densitometry technique. The equipment in this case is used exclusively stationary. The essence of the method is that the patient is placed on a special table, under which there is an X-ray source, and above the table there is a device for processing and reading the resulting image. During the study, you can not breathe and move, so as not to provoke blurring of the image. A special device that reads all the information moves smoothly over the patient during the diagnostic process and displays the necessary data on the computer monitor.
After the technical part of the procedure, specialists begin to read the results of densitometry. In order to diagnose a patient with osteoporosis, the doctor must analyze the T- and Z-criteria obtained as a result of densitometry. The T-criterion indicates a comparative characteristic of bone density in the examined patient and a normal value in women in the age group from 30 to 35 years. The Z-score, on the other hand, gives an idea of the comparison of the patient’s bone density and the normal value of this indicator for the age group to which the patient belongs. Specialists take into account the following ranges of normal and pathological diagnostic results according to the T-criterion:
- a T-score with values ranging from +2,5 to -1,0 is considered normal;
- osteopenia can be diagnosed in patients with a T-score of -1,5 to -2,0;
- osteoporosis is evident with a T-score in the range of -2,0 and below;
- a severe form of osteoporosis is given to patients if their T-score is -2,5, such numbers will be manifested by a bone fracture with a minor injury, a slight fall.
According to the Z-criterion, doctors conclude that additional examination is necessary. Such a decision is made with significant deviations of this parameter from the accepted norms.
Prevention and early diagnosis of osteoporosis
A rheumatologist is engaged in the treatment of osteoporosis, however, not only he, but also an endocrinologist, gynecologist, orthopedist, therapist and others can refer the patient to densitometry, if there are appropriate indications.
If a possible development of osteoporosis is suspected, the rheumatologist will definitely prescribe the appropriate diagnosis to the patient, and also recommend eating foods containing a lot of calcium, for example, milk or low-fat yogurt, hard cheeses – parmesan, Swiss, cheddar, canned sardines, sesame oil, almonds, bananas .
Densitometry in case of suspected osteoporosis will help the doctor to quantify the decrease in bone mass, see architectonics with a disturbed structure, assess the risk of bone fractures at a given calcium level, diagnose concomitant diseases that can lead to other serious consequences or have already caused osteoporosis in a patient .
Among other methods for determining bone mineral density, which can be used as concomitants in the treatment of osteoporosis after undergoing densitometry, ordinary radiography is distinguished. It allows you to accurately determine the architectonics of the bone and identify osteoporosis with a loss of more than 20% of bone mass (for reference, densitometry allows you to diagnose this disease with a loss of only 2-2,5% of bone mass). Additional diagnostic methods include the determination of biochemical markers of bone tissue metabolism, characterizing metabolic processes in the study area; biopsy is a traumatic procedure for taking material by surgical intervention to determine the characteristics and processes that take place in it.
If all the necessary information is available, a rheumatologist or nutritionist will make the correct diagnosis and prescribe therapy that will help put all the parameters of the patient’s bone tissue in order. That is why densitometry is the method of choice for diagnosing osteoporosis and preventing the severe complications that this disease causes, including when treated incorrectly.