The Bone Wellness Centre – DEXA Toronto

• Dual Energy X-ray Absorptiometry (DEXA) is the gold standard for measuring body fat!

• This test measures one’s body fat & gives a 3-dimensional measurement of:  Fat Tissue Mass (Subcutaneous Fat & Internal Visceral Fat), Lean Muscle Mass and Total Body Mineral Content (Total Skeletal Mass & Bone Density)

• It is safe, simple, & painless.

• The patient lies on a table on their back for 6 – 12 minutes – a small X-ray scanner called a densitometer takes a picture of the total body – The patient breathes normally but should remain still.
• The radiation from this test is minimal – one/twentieth of a chest x-ray. In simpler terms, it is less than a one-way flight from Toronto to Vancouver or less than a daily dose of natural background radiation.
• Our centre has cutting-edge technology: The Lunar Prodigy Advance Machine by GE. The only direct digital bone density machine with the latest advancements in densitometry science that is both accurate and precise for the total body (total fat, lean muscle), spine, hip, and forearm assessments.

At The Bone Wellness Centre, the DEXA scan typically takes between 6 to 12 minutes to complete. During this time, you will be asked to lie on a flat table while a scanner arm moves over your body to capture images.  You will be with us for 30 minutes in duration. This includes the scan, analysis, immediate results and discussion of your data.

DEXA uses a 3-Dimensional model to measure body fat. It divides the body into fat tissue mass (subcutaneous fat & internal visceral fat), lean muscle mass, and total body mineral content (total skeletal mass & bone density). The total body scan shows the skeleton & soft tissue. It directly measures the percent body fat for the entire body and sub-regions. It can show the muscle, fat & bone in grams/pounds for the entire body and for the arms, legs & trunk. The total body composition test also looks at fat distribution using the android (waist) to gynoid (hip) ratio.  Furthermore, it measures your RMR (Resting Metabolic Rate) and your RSMI (Relative Skeletal Muscle Mass Index).

DEXA boasts accuracy, reproducibility, safety, speed and simplicity. No other technique can match the results obtained from DEXA. Measurements of body composition help show how lean mass and body fat change during health and disease.

Skin callipers: Measures only fat under the skin, high likelihood of technical error, not good for lean or obese people

Bioelectrical impedance analysis (BIA): High rate of false positive and false negative results, too many variables to control

Underwater Weighting: Being submerged in water requires heavy equipment and is time-consuming

Bod Pod: Only a two-dimensional reading based on air displacement, not readily available, very expensive

CT: Very high dose of radiation and expensive, not readily available for body fat measurement

MRI: Extremely expensive, not readily available for body fat measurement

Body weight alone is not a clear indicator of good health because it does not distinguish how many pounds are fat and how many are lean body mass. It is not the amount of weight measured but the amount of fat in the body that is potentially dangerous to health. Excessive body fat is a serious health risk & can increase one’s risk for diabetes, heart disease, cholesterol, hypertension, gout, joint disease, musculoskeletal problems, cancer, gall bladder disease, sleep apnea & respiratory distress. Inadequate body fat can lead to malnutrition, osteoporosis, or anorexia. The body needs a certain amount of fat to regulate our body temperature, insulate our internal organs and provide our body’s energy storage.

• We cannot do the test if you are pregnant.
• If you had a dye (contrast media) injected from a CT or MRI procedure; any GI series; a barium study; or a radioisotope injection in the past week, please reschedule in 3 weeks as these substances may interfere with the test results

On the day of your scan:

• Clothing:  Please wear light/thin weight comfortable clothing with NO METAL – A T-shirt with shorts, or thin jogging pants are ideal to wear for the procedure.  (Please no zippers, metal buttons, heavy denim, thick jogging pants or bras with underwire or hooks). Your glasses, hair pins and jewellery should all be removed prior to the scan. Please remove your cell phone, wallet, keys, coins etc.  Please leave your hair open for the scan.
• Exercise:  Try not to exercise prior to your test, you can do so after the scan as you may lose fluid in the body during a vigorous exercise program.  You can resume normal activities after your DEXA Scan.   
• Fluids:  Normal Fluid Intake – you may have about 2-3 glasses (you may have your tea, coffee, juice) please don’t over hydrate
• Food:  You may have a light meal – Don’t consume a very fatty meal e.g. fried fish n chips right before the scan
• Medications:  You can take your prescribed medications as usual.  Please don’t take calcium supplements the night before or on the day prior to your DEXA scan appointment
• Metal:  Any metal inside the body (metal plates, pins, screws, dental work, metal prosthetic joints) or piercings that can’t be removed will be consistent from one scan to the next and will be added to the amount of bone.  Please don’t worry if you can’t remove some metal, we will still be able to scan you.
• Female patients can’t be pregnant
• Tests that interfere with DEXA:  If you have had any of these tests this week, please reschedule in three weeks time to allow no interference: Barium Enema, Contrast MRI or CAT Scan with dye & Nuclear Medicine Tests with radionuclide injections
• Follow-Up Studies: Keep a similar routine 24 hrs prior to your baseline test i.e., Eat, exercise, hydrate at the same time, try to book at similar times of the day as your last scan & try to wear the same clothing
• Follow-Up Scan is recommended in 3 months to monitor your muscle mass and body fat loss & see if your plan is working.  A baseline scan is an investment in your health.    Follow-up scan is a commitment to yourself!
• Our office is a NUT FREE and LATEX FREE facility – please kindly refrain from bringing these items into our office

Please kindly email us for pricing.

You will have to contact your insurance provider regarding coverage. If you have a healthcare spending account, the cost may be reimbursed.

DEXA Scans are extremely low in exposure, less than a flight from Toronto to Vancouver and less than natural background radiation for the day!

Radiation Effective dose (uSv)
Government of Canada – Radiation Doses

Radiation Dose Examples (Source: Canadian Nuclear Safety Commission)

Radiation levels are measured in: 1mSv (millisieverts) = 1,000μSv (microsieverts)

Metal inside the body will be added as bone and will be consistent from scan to scan and comparative results will be valid.

Implants will lean out DEXA measurements;  they will decrease the body fat.  If the implant is filled with silicone, the body fat will be impacted more than if the filler material is saline.  As long as the implants remain in the body, the results can be compared.  If the implants are removed, a new baseline scan would be required.

It is best to have normal hydration levels for the scan.  Water is not fat or bone mineral content and is thus added to lean tissue.  If one is extremely dehydrated or fasting for long periods prior to the scan, then this can reduce the total lean tissue values.  If one is extremely hydrated, then this can increase the lean tissue values.

No, our in house physician does the prescribing for the scan.

DEXA scans use a very low level of x-ray consisting of two different beams. One is a higher energy beam, while the other is a lower intensity. The lower intensity beam is only absorbed by soft tissue (muscle and fat), where as the higher intensity beam gets absorbed both by bones and by soft tissue. These differences in absorption are used to determine bone mineral density (BMD) and body composition values.