injection of a small amount of radioactive material, a special
camera records the distribution of radiotracer throughout
the skeleton. This information is translated by a computer
into two-dimensional images that are recorded on film. Nuclear
scans can often identify skeletal abnormalities months before
they would be detectable on x-rays.
Purpose of the Test
primary bone tumors or metastatic cancer that has spread to the
bone from other parts of the body, particularly when x-ray findings
are normal but cancer is still suspected.
stress fractures that do not always appear on x-rays and to monitor
To detect or
evaluate bone infection, inflammation, arthritis, and other bone
the site of an abnormality before a bone biopsy or surgery is
To aid in the
evaluation of unexplained bone pain.
Who Performs It
A nuclear medicine
This test should
not be performed in pregnant or breastfeeding women because of
possible risks to the fetus or infant.
It may not
be possible to perform this scan in people with poor kidney function
because their bones may not absorb sufficient amounts of the
injury that results from trauma may be missed if the scan is
performed within the first 24 hours.
such as multiple myeloma (a tumor of the bone marrow), may not
appear on a bone scan, and other tests will be needed to detect
Before the Test
jewelry or metal objects before the test begins.
What You Experience
injects a very small amount of a radiotracer into a vein, usually
in your arm. (Other than the minor discomfort of this injection,
the procedure is painless.) You may experience brief, mild nausea
and flushing as the material enters your bloodstream.
You will wait
for 1 to 3 hours before the scan is performed. During this time,
you will be encouraged to drink several glasses of water to help
the kidneys filter out any radioactive material that is not picked
up by the bone.
before the scanning, you should empty your bladder to eliminate
any radiotracer that might obstruct the view of the underlying
You will be
asked to lie down on an examining table. A large scanning camera
is passed over your body, recording the gamma rays emitted by
the radiotracer in the bones.
You must remain
still during the scan, which may cause some numbness or stiffness.
(Ask the doctor if a pillow or pads can be placed on the table
for your comfort.) At several points during the procedure, the
examiner may instruct you to change your position.
The scan itself
usually takes about 30 to 60 minutes.
Risks and Complications
The trace amount
of radioactive material used in this test is not associated with
any significant risks or complications.
rare cases, patients may be hypersensitive to the radiotracer
and may experience an adverse reaction.
After the Test
You may resume
your normal activities after the test.
fluids to help your body eliminate the radiotracer. Most of the
radioactive material is excreted in the urine within 6 to 24
Blood may collect
and clot under the skin (hematoma) at the dye injection site;
this is harmless and will resolve on its own. For a large hematoma
that causes swelling and discomfort, apply ice initially; after
24 hours, use warm, moist compresses to help dissolve the clotted
A doctor examines
the scans for any abnormalities and interprets these findings
in conjunction with your medical and surgical history, x-ray
findings, and laboratory test results. Healthy bone is characterized
by uniform absorption of the radiotracer throughout the body,
while areas of increased uptake appear as "hot spots" on
the scans, indicating new bone growth associated with various
abnormalities, including tumors, arthritis, fractures, infections,
and degenerative bone and joint changes.
If a definitive
diagnosis can be made, appropriate treatment will be initiated.
In some cases,
additional tests, such as a bone biopsy, may be needed to further
evaluate abnormal results.
From The Johns Hopkins Consumer Guide to Medical
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