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BONE
DENSITY
What
is a Bone Denisty exam?
A
bone density test, or scan, is designed to check for osteoporosis,
a disease that occurs when the bones become thin and weak. Osteoporosis
happens when the bones lose calcium and other minerals that keep
them strong. Osteoporosis begins after menopause in many women,
and gets worse after age 65, often resulting in serious fractures.
A bone density scan measures the strength of your bones and determines
the risk of fracture.
Today,
most people will get a bone density scan from a machine using a
technology called Dual Energy X-ray Absorptiometry or DEXA for short.
This machine takes a picture of the bones in the spine, hip, total
body and wrist, and calculates their density. If a DEXA machine
is not available, bone density scans can also be done with dual
photon absorptiometry (measuring the spine, hip and total body)
and quantitative computed tomography scans (measuring the spine).
Bone density scanners that use DEXA technology to just measure bone
density in the wrist (called pDEXA scans) provide scans at some
drugstores. Yet these tests are not as accurate as those that measure
density in the total body, spine or hip--where most fractures occur
To
take a DEXA bone density scan, the patient lies on a bed underneath
the scanner, a curving plastic arm that emits x rays. These low-dose
x rays form a fan beam that rotates around the patient. During the
test, the scanner moves to capture images of the patient's spine,
hip or entire body. A computer then compares the patient's bone
strength and risk of fracture to that of other people in the United
States at the same age and to young people at peak bone density.
Bones reach peak density at age 30 and then start to lose mass.
The test takes about 20 minutes to do and is painless.
The
DEXA bone scan exposes the patient to only a small amount of radiation--about
one-fiftieth that of a chest x ray, or about the amount you get
from taking a cross-country airplane flight.
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Radiology
Appointment Line:
617-665-1298
Whidden
campus co-located with Breast Imaging at 96 Garland St.
Monday - Friday
8:00am - 4:30pm
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