Bone Density: A Clue to Your Future
DEXA bone density scans: Will you glide into your golden years or live out a fractured fairy tale?
When Should You Get That First Bone Density Scan? continued...
And some women should get the test even earlier, Tosi says. For instance, a
woman who is 40 or so and suffers a "fragility" fracture -- a bone
break that occurs when you fall from a standing height (about 5.5 feet or less)
-- should get a bone density test, Tosi says. That type of fracture, she
reasons, doesn't occur to strong bones.
Women who have been on high-dose corticosteroid medications to treat
autoimmune disease such as lupus, along with women who have thyroid disease,
should consider a bone density test, too, Tosi says, because they are more
likely than others to have lower bone density.
The Bone Density Test Itself
At least nine different methods are used to measure bone density, according
to the National Osteoporosis Foundation, but the most commonly used test is
called Dual Energy X-ray Absorptiometry or DEXA. It measures the bone mass at
the spine, hip, or total body.
The bone density test is totally noninvasive, says Kim Templeton, MD, an
associate professor of orthopaedic surgery at the University of Kansas.
"There are no injections," Templeton says. "You lay on a table and
the scanner scans you. The hardest part is lying there, for about 15 to 20
minutes." The average cost is about $150, says Templeton.
And a bone density scan is not the same as a bone scan, Templeton says,
although women often mix up the two. A bone scan is a kind of nuclear medicine
test in which a radioactive tracer is injected into a vein so the doctor can
scan the body, looking for bone tumors or other problems such as infection.
Bone Density Scans: Your Results
The bone density test produces two scores: the T score and The Z score.
"The T score looks at the amount of bone you have compared to someone
with peak bone mass (a 30-year-old healthy adult)," Templeton says.
"The Z score is looking at someone your age and your same gender, to find
out how you stack up with people your own age."