Densitometry is a study of bone mineral density (aka densitometry). Thanks to densitometry, it is possible to detect osteoporosis at an early stage of its development, as well as to determine its degree and monitor the treatment. What are the indications for densitometry? What is the examination about? How to interpret its results?

Densitometry( densitometry, osteodensitometry ) allowsto measure bone mineral density . It is a type of X-ray examination, thanks to which it is possible to estimate the risk of fractures, as well as select the appropriate type of therapy.

Densitometry (bone density testing) - how does it work?

The operation of the densitometer is easy to imagine, because it resembles light penetrating through the curtains into our apartment on a sunny day. The amount of light that reaches our eye depends on the thickness of the curtains. Suppose the curtains are our bones, the sun is X-rays, and our eye is an electronic detector that measures how many rays pass through the bones. If the curtains are very thick, little light will pass through them. But if we replace them with a thin cloth - the amount of light passing through it will increase. It is similar with bones - if they are dense, strong, few X-rays will pass through them, while when they are brittle, porous - more rays pass through them. The amount of rays that pass through the bone is measured and converted by an electronic detector into figures that allow the doctor to assess bone density.

Densitometry (bone density test) - indications

Ok. In 40 years of age, the test should be performed by anyone with a family history of osteoporosis. In addition, it should be performed prophylactically by women around 50 and men around 60. The most common indications for the test are:

  • low body weight
  • past fractures
  • low level of calcium and / or vitamin D in the diet
  • little physical activity
  • late first menstruation
  • frequent births in short intervals
  • early menopause
  • smoking and alcohol abuse

People who are chronically ill, at risk of secondary osteoporosis (e.g. untreated peptic ulcer disease, hyperthyroidism andthyroid gland, kidney or liver failure, malabsorption syndrome).

Densitometry (bone density test) - how to prepare for the test

You don't need to prepare yourself for the examination. Before starting the test, inform your doctor about your medical conditions (e.g. thyroid disease, diabetes) and the medications you are taking. If a contrast test (e.g. computed tomography) was performed a few weeks before densitometry, you must also notify the doctor, because there must be a break between the tests. On the day of the examination, you should not take any medications or dietary supplements with calcium.

Densitometry (bone density test) - what is it? how is it going?

Height and weight are measured before densitometry. Everything that contains metal (e.g. jewelery) should be removed for the examination. The bones most likely to break in osteoporosis are usually examined. These are: the lumbar spine, the neck of the femur, the wrist and the forearm. When the back or hip is examined, we lie down on the measuring table, and when the hands are examined - we sit. The arm of the apparatus emitting the rays moves over the examined part of the body. It takes a few minutes, during which time you need to lie down or sit still. After performing densitometry, you can immediately return to normal activities.

Bone density testyoung children or people who cannot cooperate with a doctor (e.g. mentally ill) may require general anesthesia.

Densitometry (bone density test) - how to interpret the test results?

  • + / - 1 - valid values ​​
  • from 1 to - 2.5 - low bone mass (osteopenia)
  • below - 2.5 - osteoporosis
Worth knowing

Heel bone density test is not reliable

Some clinics offer ultrasonic densitometry. In this case, the calcaneus is examined. The shoe on one leg is removed and all items on it up to the knee are removed. Sometimes the foot is rubbed with a dilute aqueous alcohol solution to degrease its surface. Then you put your foot in a special chamber of the apparatus, rest it on a support and do not make any movements. During the test, the foot is immersed in water with the addition of a small amount of detergent, at a temperature close to body temperature. However, this study is unreliable. The only test that allows you to examine bone density is the X-ray examination described above.

About the authorAnna Jarosz A journalist who has been involved in popularizing he alth education for over 40 years. Winner of many competitions forjournalists in medicine and he alth. She received, among others The "Golden OTIS" Trust Award in the "Media and He alth" category, St. Kamil awarded on the occasion of the World Day of the Sick, twice the "Crystal Pen" in the national competition for journalists promoting he alth, and many awards and distinctions in competitions for the "Medical Journalist of the Year" organized by the Polish Association of Journalists for He alth.

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