Bone scan is an imaging test for detecting various types of bone abnormalities. This diagnostic procedure is suggested by doctors on suspecting bone infections, bone loss or any type of injury.
Why is it done?
The sole purpose of a bone scan is to find out the exact abnormality in order to proceed towards the right treatment. A bone scan is done under the following circumstances:
- Fractures in bones from injury and stress
- Bone cancer – spread of cancer to bones and origin of cancer
- Bone diseases- Paget’s disease, Arthritis, Fibrous dysplasia
- Different types of bone infections like osteomyelitis
- Loss of bone density
- Abnormality in blood supply to bones and tissue functions, like avascular necrosis)
How to prepare for the test?
- Your food and drink will be normal and you don’t need to keep your stomach empty before the test.
- An important thing that you must remember is – tell your doctor about all the medicines you are taking (especially bismuth and barium based drugs) irrespective of their dose being temporary or long term.
- Your may also need to wait for 4 days if you have undergone an X-ray with barium and bismuth.
- You will need to discontinue some medicines, mainly those with bismuth and barium at least for 4 days before the test.
- You must tell your doctor if you are pregnant because bone scan is usually not performed during pregnancy.
- It may be also restricted to breastfeeding mothers or they might be given a special formula to eliminate the breast milk for 1-2 days to get rid of radioactive traces.
- Lastly, feel free to clarify with your doctor if you have any qualms in your mind regarding the test.
How is it done?
The scan is performed by specialized doctor- nuclear medicine technologist
- You need to take off your jewelry and change your clothes with the garment given by your doctor.
- An injection containing a radioactive tracer will be given in a vein of your arm and it takes 2 to 5 hours for the tracer to move through your body and bind with the bones.
- During this period, you will be asked to drink at least 6 glasses of water to eliminate the extra radioactive substance (that has not settled in your bones) through urination. Emptying the bladder is a must before starting a pelvic bone scan.
- You will have to lie down on your back over a table and your doctor might ask you to take different positions to get accurate view of the bones.
- A camera will be scanning your bones for the radiation emitted by the tracer. The radioactive emission (gamma rays) are then converted into an electrical signal and sent to a computer which produces the pictures. Scanning takes about an hour to complete.
- Your doctor might suggest another advanced test called additional imaging called single-photon emission computerized tomography (SPECT).
Results of Bone Scan
The results are interpreted by a radiologist and they appear in the following manner:
- The pictures that show darker "hot spots" are the areas where the tracer has accumulated and are indicative of a bone disease or infection or fracture.
- Cold spots are areas where the tracer hasn't accumulated could be an evidence for cancer.
- If the tracer has spread evenly, then your bone condition is absolutely normal
What to Expect?
- Bone scan is not the sole confirmatory test for any kind of bone disease. Your doctor will combine other types of tests like additional X-rays, MRI, blood tests, CT scan etc. to come to the final conclusion.
- A pinch of discomfort might be felt during the injection. Moving the body becomes painful when a patient is diagnosed for unexplained pain in different parts of the body or for fractures.
- The radioactive tracers usually do not trigger any allergic reaction.
Follow the advice of your doctor while he conducts the tests so that nothing interferes with its accuracy. Good luck!
Written by: Saptakee sengupta
Date last updated: January 11, 2015