Skeletal Nuclear Scan
After intravenous 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 Bone Scan
- To identify 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. Common types of cancer that may spread to the bones include breast, lung, prostate, thyroid and kidney cancer.
- To diagnose stress fractures that do not appear on x-rays and to monitor fracture healing
- To detect or evaluate bone infection (osteomyelitis), inflammation, arthritis, and other bone disorders
- To pinpoint the site of an abnormality before a bone biopsy or surgery is performed
- To aid in the evaluation of unexplained bone pain
- To detect increased or decreased bone production (metabolism)
- To assess metabolic disorders, such as osteomalacia, renal osteodystrophy, primary hyperparathyroidism, osteoporosis, complex regional pain syndrome, and Paget’s disease
Who Performs Bone Scan
- A nuclear medicine technician
Special Concerns about Bone Scan
- 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 radiotracer.
- A skeletal injury that results from trauma may be missed if the scan is performed within the first 24 hours.
- Certain tumors, 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 them.
Before the Bone Scan
- Remove any jewelry or metal objects before the test begins.
- Tell your doctor if you are pregnant or may be pregnant.
- Avoid taking medicine with bismuth, such as Pepto-Bismol, for 4 days before the test.
What You Experience during Bone Scan
- The doctor 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.
- Immediately before the scanning, you should empty your bladder to eliminate any radiotracer that might obstruct the view of the underlying pelvic bones.
- 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 of Bone Scan
- The trace amount of radioactive material used in this test is not associated with any significant risks or complications.
- In extremely rare cases, patients may be hypersensitive to the radiotracer and may experience an adverse reaction.
After the Bone Scan
- You may resume your normal activities after the test.
- Drink extra fluids to help your body eliminate the radiotracer. Most of the radioactive material is excreted in the urine within 6 to 24 hours.
- 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 blood.
Results of Bone Scan
- 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.
The Johns Hopkins Consumer Guide to Medical Tests
Simeon Margolis, M.D., Ph.D., Medical Editor
Updated by Remedy Health Media