DEXA scan

A DEXA scan is a medical imaging test used to measure bone density and/or body composition. DEXA stands for dual-energy X-ray absorptiometry.

Why a DEXA scan?

DEXA scans are used to detect conditions such as osteoporosis (bone loss) and sarcopenia (severe loss of muscle mass). Osteoporosis is a condition in which bone mass decreases. This increases the risk of bone fractures. In sarcopenia muscle mass is lost and problems occur in daily functioning.

DEXA scans are also able to measure the total composition of the body. This provides insight into the amount of body fat and muscle mass. This makes the test interesting for athletes or people who are overweight and want to know their body fat percentage and muscle mass.

How does a DEXA scan work?

During a DEXA scan the patient lies on a table while the device sends a low dose of X-rays through the body. The device measures how much radiation the bones and soft tissues of the body absorb. Not every tissue absorbs the same amount of radiation. A DEXA scan measures bone density and body composition this way. These values are then compared with the normal values for someone of the same age and sex.

A DEXA scan is a simple and painless examination that usually takes less than 15 minutes. The patient does not need to undress and there is no special preparation needed. To get the best result the patient must remain still.

It is important to know that DEXA scans are not suitable for everyone. Metal implants, such as artificial joints, can negatively influence the test. The measurement is then not entirely accurate. During pregnancy it is also not advisable to have a DEXA scan. This is to avoid exposing the unborn child to X-rays.

Comparison with other imaging techniques

A DEXA scan is the best way to measure bone density. X-rays are less accurate and only show bone loss when bone mass has already decreased severely. Moreover, exposure to radiation with a DEXA scan is many times lower than with a normal X-ray. CT scans and MRI scans are also less suitable, because they are more expensive and less easily accessible than DEXA scans.