Definition A bone scan is a test used to find cancer, infection, or injuries in the bone. It may also be used to check a person's response to treatment for certain bone conditions.
Who is a candidate for the test? A doctor may recommend this test to:
detect whether cancer has spread to the bone
find an infection in the bone
detect a tumour in the bone
follow a person's response to treatment for conditions like Paget's disease, a condition that destroys bone
find a fracture or injury to the bone
How is the test performed? A bone scan takes about an hour, not including pre-scan waiting time. As with most tests, a consent form is required.
A radioactive substance is injected into a vein in the arm of the person having a bone scan. Usually, the test begins after a wait of 2 to 3 hours.
When the test starts, the person having a bone scan lies flat on his or her back on a table. A special camera is positioned so the entire body can be scanned. Rays from the radioactive substance are detected by the camera, which sends pictures to a computer.
In a normal study, the table will not move during each scan. Depending on the health issue in question, though, more focused views may be needed and the scanner may move 10 to 15 centimetres (4 to 6 inches) per minute while pictures are being taken.
In the 3-phase study, the first scans are done every 5 seconds for 60 seconds. A blood pool image, a special image to follow the radioactive substance while it travels through the blood vessels, is done next. Then the person needs to wait for 2 hours before scans are resumed.
After the bone scan is done, the person will be asked to wait to get dressed until the technologist is sure the pictures are adequate.
What is involved in preparation for the test? Before the test, the person will undress completely and put on an examination gown. All jewellery and metal objects-including pierced body jewellery-must be removed so they will not interfere with the examination. A woman will be asked if she is pregnant.
Usually no other special preparation is needed. However, the person should check with the examination centre or doctor before the day of the examination to be sure.
What do the test results mean? This test can:
show specific areas of irregular bone metabolism, which may suggest certain diseases based on the pattern of abnormality
detect abnormal blood flow to a particular bony region
help evaluate metabolic diseases that affect bone, such as certain thyroid conditions
detect the spread of cancer to the bones and evaluate results of cancer treatment
diagnose bone changes from a condition called reflex sympathetic dystrophy, a disorder of nerves that may cause pain, usually in the hands or feet
The amount of radiation to the patient during the procedure is negligible
Author: Reviewer: HealthAnswers Australia Medical Review Panel Editor: Dr David Taylor, Chief Medical Officer HealthAnswers Australia Last Updated: 1/10/2001 Contributors Potential conflict of interest information for reviewers available on request
