DXA measurement, also known as dual x-ray absorptiometry, is a diagnostic procedure used mainly for measuring bone density. It can also determine the body composition and thus determine the percentage of body fat, lean mass and bone mass of the examined person. The technique behind the procedure is based on X-rays. In recent years, DXA measurement has been widely used, especially in the field of bone density measurement. The measurement can be used to detect existing and incipient osteoporosis and to initiate treatment.
Principle
The principle of DXA measurement is based on the principle of the X-ray image. Unlike a normal X-ray image, however, several images are taken, which differ in their radiation density. This procedure allows the density of the bone to be calculated exactly from the images.
The calculation is performed by a computer, usually connected to the device. The ideal place for the execution is on the one hand the hip bone and on the other hand the lumbar spine. Other parts of the body can also be examined, although in this case the accuracy of the measurement results decreases. Even though osteoporosis affects the whole body, measurements are preferably taken on the hip joint and spine. The reason for this is the comparability of the performance and calculation of the values compared to other tested persons and study results as well as the accuracy of the results.
Indications
The most common indication for the performance of a DXA measurement is the suspicion of osteoporosis. Statistically, the disease affects women much more frequently than men, with women often being diagnosed with the disease after menopause. Children are usually not affected.
Osteoporosis is accompanied by a loss of calcium in the bones. The structure and stability of the bone changes, the bone becomes thinner and the risk of bone fracture increases significantly. DXA measurement can also be used to monitor the progress of already diagnosed osteoporosis or other diseases associated with altered bone density.
A DXA measurement can provide information about the risk of spontaneous bone fracture. The risk is based on age, body weight, any previous fractures, family history and certain behaviours such as smoking, alcohol and other drugs. Taking these factors into account and creating a DXA file for the person concerned enables the treating physician to create a risk profile. The DXA measurement is recommended for:
- Women after their menopause, if no estrogen is taken or risk factors are present.
- If there is a personal history of fractures and a family history may be known.
- When clinical symptoms are known that may be associated with loss of bone density.
- If certain drugs are taken, which can adversely affect the density of the bone.
- If you have type I diabetes, liver or kidney disease or a family history of osteoporosis.
- If there is an overactive thyroid gland (hyperthyroidism).
- If there is an overactive parathyroid gland (hyperparathyroidism).
- When a fracture has occurred although only minor trauma has occurred where no fracture would have been expected.
- If a fracture of the spinal column or other signs of osteoporosis have been detected by imaging techniques.
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