Bone Density
Test
WHAT IS A BONE MINERAL DENSITY (BMD) TEST?
Following a comprehensive medical assessment, your doctor
may recommend that you have your bone mass measured. Bone
mineral density (BMD) test measure bone density in the
spine, hip, and/or forearm. These are the most common
sites of fractures due to osteoporosis, a disorder in
which bones gradually become thinner and weaker. Osteoporosis
is often called the “silent killer” because
the condition can often go undetected until it is severe
and fractures begin to occur. Until the age of about 30,
you build and store bone efficiently. Then, as part of
the natural aging process, your bones begin to break down
faster than new bone can be formed.
RISK FACTORS FOR OSTEOPOROSIS
• Being female
• Being thin and/or having a small frame
• Advanced age
• A family history of osteoporosis
• Estrogen deficiency as a result of menopause,
especially early or surgically induced
• Anorexia nervosa
• Low lifetime calcium intake
• Use of certain medications, such as corticosteroids
and anticonvulsants
• Low testosterone levels in men
• An inactive lifestyle
• Current cigarette smoking
• Excessive use of alcohol
• Being Caucasian or Asian, although African Americans
and Hispanic Americans are at significant risk as well
WHY WOULD I NEED A BMD TEST?
A bone density test can:
• Detect osteoporosis before a fracture occurs
• Predict your chances of fracturing in the future
• Confirm a diagnosis of osteoporosis if you have
already suffered a fracture.
• Determine your rate of bone loss and/or monitor
the effects of treatment if the test is conducted at intervals
of a year or more
HOW IS BONE DENSITY MEASURED?
Bone density is measured through painless, noninvasive
scanning techniques based on X-ray radiation. These techniques
require you to be positioned for the scan and hold still
while it is being completed. Dual Energy X-ray Absorptiometry
(DEXA) measures the spine, hip, and/or forearm, and is
the most widely used technique available. The procedure
exposes the patient to very little radiation, needs little
scanning time, is inexpensive and is highly accurate.
Because of its precision, DEXA is well suited to making
serial (repeated) measurements. Serial bone density measurements
may be done to track bone loss over time, to evaluate
the effectiveness of treatment, or as part of a clinical
trial for a new potential treatment for osteoporosis.
INSTANT VETEBRAL ASSESSMENT
Instant Vertebral Assessment (IVA), a feature on the Hologic
Discovery bone densitometer, provides high-resolution,
single-energy images to reveal existing vertebral deformities.
An existing spine fracture increases the risk of future
spine fractures five-fold and doubles the risk of hip
fracture. Therefore, the combination of IVA and BMD assessment
helps clinicians improve risk stratification and enhance
their ability to accurately target those patients who
need therapy.
HOW DO I PREPARE FOR AN EXAM?
Wear comfortable clothing with no metal zippers, buttons,
or buckles. Let the technologist know if you are pregnant
or think you may be. Also let the technologist know if
you have had recent fractures, metal implants inside your
body (hip replacements or back surgeries). It is also
important to inform the technologist if you have had a
recent nuclear medicine scan or a barium exam.
WHAT CAN I EXPECT DURING MY EXAM?
During a DEXA bone density scan, you will be asked to
lie on a table on your back. The scanner arm will move
back and forth over the part of your body being scanned.
Typical DEXA exams are completely painless and only take
5 to 7 minutes to perform.
WHAT DO THE RESULTS MEAN?
Your bone density is compared to two standards, or norms,
known as “age matched” and “young normal.”
The age-matched reading compares your bone density to
what is expected in someone of your age, sex, and size.
The young normal reading compares your density to the
optimal peak bone density of a healthy young adult of
the same sex.
The information from a bone density test enables your
doctor to identify where you stand within ranges of normal
and to determine whether you are at risk for fractures.
In general, the lower your bone density, the higher your
risk for fractures. Test results will help you and your
doctor decide the best course of action for your bone
health.
RESTRICTIONS: Patients Cannot Receive
Testing If:
1. Scheduled less than 5 days after Barium procedures
2. Undergoing radioactive iodine thyroid therapy
3. Weight is over 270 lbs.
4. Non-Ambulatory
5. Took a Calcium Supplement the day of the test
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