Disadvantages | Bone density measurement using the DEXA method

Disadvantages

Despite the low dose of radiation exposure necessary for the DXA measurement, there is still a certain residual risk of radiation damage. In a healthy, adult person, the risk is low, and in most cases the advantages of the method outweigh the low risk to the body. However, this risk means that children and adolescents, and especially pregnant women, are not examined with the DXA measurement. It is therefore essential to inform the treating physician of a possible pregnancy before the measurement is performed.

Borders

The DXA measurement cannot determine exactly which patient may have a fracture at which location, it is only possible to determine the relative risk of the affected person. The accuracy and feasibility of the DXA measurement is no longer possible in people who have had bone changes in the spinal area or a previous spinal surgery. Similarly, fractures may affect the accuracy of the examination, which is why computed tomography is usually indicated in these cases.

Alternatives

DXA measurement is the most commonly used method for determining bone density. However, other methods may be used for measurement for certain reasons.

• An alternative to the DXA measurement is the so-called quantitative computed tomography (QCT).

  The advantage of this method is the possibility to produce a 3D representation of the body. However, the accuracy despite a significantly higher radiation exposure during this measurement is a not unimportant disadvantage.

• Peripheral quantitative computed tomography (pQCT) is another method that also displays the body in a 3D image. However, since this method only measures peripheral parts of the body, studies show that the results of this method do not come close to the accuracy of the results of a DXA measurement and thus cannot adequately document changes that are associated with osteoporosis, for example.
• There is also another method that does not involve any X-rays at all, the so-called quantitative ultrasound examination (QUS). However, this method is also only of limited use in monitoring the course of diseases with altered bone density, as changes cannot be assessed.