Bone Densitometry / Osteoporosis

The following examinations are performed:

• Lumbar spine
• Hip (left, right or both)

Bone densitometry method: there are various methods available to measure bone density. However, the most popular and reliable method is the Dual Energy X-ray Absorptiometry (DEXA) technique. It is a method that uses low-energy X-rays.

Who should undergo bone densitometry
• Women over 65
• Women over 65 with risk factors for fracture
• Menopausal women who run a greater risk of fractures due to small body frame or previous history of fractures
• Men over 70
• Men over 70 with risk factors for fracture
• Elderly individuals with conditions related to low bone mass or connected to bone mass loss
• Adults taking medication associated with low bone mass, such as cortisone
• Patients already receiving drug therapy for low bone mass and who need to have their results assessed

On which anatomical parts is the measurement performed?
According to the World Health Organization, two parts of the body are most suitable for bone densitometry: (1) the vertebrae of the lumbar spine and (2) the hip. However, it is possible to perform the measurement on other parts of the body (distal third of the radius). This is quite rare, though, while it cannot be performed on all bone densitometry devices.

How is the exam performed?
Bone densitometry is a painless, bloodless and safe exam. During the exam, patients lie under the special scanner, without having to take their clothes off. The scanner moves along the entire body of the patient so as to take an image of the area of interest. The procedure does not last longer than 15 minutes.

Interpretation of results
The results are expressed in T-score values with the help of a computer. The T-score value provides an indication of how high or low the bone density of a patient is, compared to the bone density of a healthy 30-year-old adult. Patients may be listed under three categories based on their bone density value:

          T-score > -1.0 NORMAL
-1.0 > T-score > -2.5 OSTEOPENIA
          T-score < -2.5 OSTEOPOROSIS

Who cannot undergo bone densitometry?
(1) Women who suspect they are pregnant.
(2) Patients who have very recently undergone other diagnostic exams that required administration of contrast mediums, such as barium or Gastrografin (only pertains to lumbar spine measurement). In this case, the exam is rescheduled for a few days later, so that the contrast medium has left the body. 

What can affect the accuracy of the method?
Bone densitometry using the DEXA technique is an effective method for diagnosing and assessing the level of osteoporosis. However, its accuracy may be affected in the event of patients with compression fractures in the spine or presence of degenerative hypertrophic lesions in the vertebrae.  Additionally, it is recommended that the exam is performed at the same time every year and at the same diagnostic center (i.e. same device) each time, to achieve better comparative results between exams. Using the same device is quite important, as there are many different types of scanners, which use different processing software (Lunar, Hologic). 

What happens with radiation?
The method uses X-rays. However, patients receive a very low radiation dose. As an indication, the dose is less than 1/10 of the radiation dose delivered by a standard chest X-ray and smaller than the dose each person receives daily from environmental exposure.

All exams are performed using a LUNAR DPX device.