Bone densitometry

Bone densitometry is a medical imaging exam that measures the bone mineral density of the axial skeleton (spine) and appendicular skeleton (hips). It helps assess fracture risk and detect possible osteoporosis (a disease involving loss of bone mineral density). This exam is performed at the Radiologie Dix30 clinic in Brossard, on Montreal’s South Shore. It is covered by RAMQ once a year.

What is bone densitometry?

Bone densitometry is based on a technique called dual-energy X-ray absorptiometry (DXA). A very low-intensity X-ray beam scans the targeted areas. Detectors measure the amount of radiation absorbed by the bones. The denser the bone, the more X-rays it absorbs. The software converts this data into a bone density value, expressed as a T-score (comparison with the bone density of a healthy young adult).

The radiation dose used is extremely low, far lower than that of a standard X-ray. It is so minimal that the technologist can remain in the exam room without any special protection.

The exam mainly looks at two areas :

• The spine, to assess the density of the vertebrae, mainly in the lumbar region ;

• The hips, to measure the density of the femoral neck and greater trochanter (upper part of the femur).

A simple X-ray of the thoracic and lumbar spine is also taken at the same time. This helps detect occult vertebral fractures (fractures that are painless and previously undiagnosed), which represent an additional fracture risk factor.

Why have a bone densitometry exam?

Your doctor may prescribe a bone densitometry exam to assess your fracture risk or monitor changes in your bone density over time.

This exam is mainly recommended in the following situations :

• Postmenopausal women, especially after age 65, because of the high risk of bone loss linked to lower estrogen levels ;

• Men over age 70, in whom osteoporosis is often underdiagnosed ;

• A history of fragility fracture, meaning a fracture that occurred after minor trauma, without a significant fall ;

• Long-term use of corticosteroids (cortisone), which promote bone loss ;

• Risk factors for osteoporosis, such as low body weight, smoking, excessive alcohol consumption, or family history ;

• Conditions associated with bone loss, including chronic inflammatory diseases, endocrine disorders, or intestinal malabsorption disorders ;

• Monitoring osteoporosis treatment to assess its effectiveness.

Bone densitometry results help your doctor estimate your 10-year fracture risk and guide any treatment decisions.

How should you prepare for a bone densitometry exam?

Before a bone densitometry exam, no fasting is required, and you may dress normally, preferably in clothing without any metal elements (buttons, zippers, etc.).

Two instructions are essential to follow :

• Do not take calcium, iron, or vitamin supplements within the 48 hours before the exam. These substances absorb X-rays and may affect the results ;

• Wait two weeks after any fluoroscopic exam using barium before having a bone densitometry exam. Residual barium in the digestive tract interferes with bone density measurement.

If both exams are prescribed at the same time, the bone densitometry exam will be performed first.

On the day of the exam, remember to bring your medical prescription and your valid health insurance card. If you have already had a bone densitometry exam, please bring your previous results. This will allow the radiologist to assess changes in your bone density.

How do I book a bone densitometry appointment at the Radiologie Dix30 clinic?

Bone densitometry is available by appointment only. You can send your prescription by fax to 450-904-0405 or by email to info@radiologiedix30.com. Our team will schedule your appointment based on your availability.

The clinic is open 365 days a year: Monday to Friday from 8 a.m. to 9 p.m., and Saturdays and Sundays from 8 a.m. to 8 p.m.

What happens during a bone densitometry exam?

Bone densitometry is performed at the Radiologie Dix30 clinic in Brossard. Please plan to arrive 15 minutes before your appointment time for check-in at reception and to open your file if this is your first visit.

Here is how the exam takes place :

• Welcome and registration : you present your health insurance card and your prescription. You will be given a medical questionnaire to inform the radiologist about your health status, medical history, and current treatments ;

• Positioning : The technologist will help you lie down on your back on the exam table, with a cushion under your knees for comfort. You may keep your clothes on, provided you are not wearing any metal objects in the area being examined. If needed, a gown will be provided ;

• Image acquisition : the machine’s arm moves slowly above you to scan the spine, then the hips. The technologist then selects the specific areas to be studied so the software can calculate bone density. A simple X-ray of the spine is taken at the same time ;

• Duration : the exam takes between 5 and 10 minutes. Please allow about 45 minutes in total for the full visit ;

• Return to activities : you can resume normal activities immediately. No special precautions are required after the exam.

Cost of a bone densitometry exam

Bone densitometry is covered by RAMQ, up to once a year. There are no fees to expect. Your valid health insurance card must be presented on the day of the exam.

Results

The exam is generally interpreted by the radiologist the same day. A detailed report is sent to your referring doctor within 2 to 5 days. Your doctor will contact you to share the results and discuss any next steps.