Bone scan

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Drawing shows patient lying on a table that slides under the scanner, a technician operating the scanner, and a monitor that will show images made during the scan.

Bone imaging is a study to visually detect bone abnormalities. Such imaging studies include magentic resonance imaging (MRI), X-ray computed tomography (CT) and especially nuclear medicine. In the latter case the patient is injected with a small amount of radioactive material such as 600 MBq of technetium-99m-MDP and then scanned with a Gamma camera, a device sensitive to the radiation emitted by the injected material.

About half of the radioactive material is localised by the bones. The more active the bone turnover, the more radioactive material will be seen. Some tumors, fractures and infections show up as areas of increased uptake. Others can cause decreased uptake of radioactive material.

About half of the radioactive material leaves the body through the kidneys and bladder in urine. Anyone having a study should empty their bladder immediately before images are taken.

The period from injection to completion can last over 4 hours. Actual images are taken for about 30 to 70 minutes. Sometimes late images are taken at 24 hours after injection.

Pregnant patients should consult with a physician before consenting to radioactive injections.