Is a bone scan the same as an MRI?
In a bone scan, also known as skeletal scintigraphy, small amounts of a radioactive material are injected into your vein to diagnose bone conditions. MRI uses strong magnetic waves/fields to diagnose conditions of any organ or structure in the body. The radioactive material (contrast) may be needed sometimes and not always with an MRI.
An MRI creates 3D images of the bone, whereas a bone scan creates two-dimensional (2D) images. The MRI provides a detailed view of the bone and its surrounding structures such as the ligaments, tendons and soft tissue. It diagnoses a bone condition more definitively and accurately than a bone scan.
Your doctor may order a bone scan for unexplained bone pain, bone injury or bone infection that can't be observed on a standard X-ray. An MRI is required usually only after the bone scan or X-ray detects some problem in the bone and when detailed imaging is needed.
When is a bone scan used?
A bone scan can often identify the earlier stages of a disease even before an X-ray can. A bone scan is used to
How do you prepare for a bone scan?
Inform your doctor if
- You are pregnant
- You are breastfeeding
- You have any major medical illness
- You are on any medications, dietary supplements or herbal supplements
If you are a breastfeeding woman, you should not breastfeed for the next two days. Feed your baby formula.
Inform your doctor if you have had an X-ray with ingestion of a barium meal within the last four days. Barium can interfere with the working of the bone scan.
Limit your intake of fluids for at least four hours before the procedure.
You will be asked to wear a gown during the bone scan exam.
Metal accessories are not allowed during the procedure.
How does a bone scan work?
A radioactive material called a radiotracer or radiopharmaceutical is injected into your body and it enters your bones and emits energy in the form of gamma rays. These rays are captured by a special camera (an imaging device) and the pictures produced are known as scintigrams. The scintigram highlights the problematic areas in the bones.
How is a bone scan procedure performed?
A nuclear medicine technologist will administer a radiotracer into a vein in your hand or arm.
You will be asked to wait for two to four hours and drink plenty of water (six to eight glasses). Once you feel like urinating, you will be asked to do so. This helps flush the radiotracer out of the urinary bladder so that it does not block the pelvis. A picture of the pelvic bone can then be taken properly.
The scanning camera will be moved over your body. You may have to remain still for brief periods. You may be asked to move into various positions during the procedure. The camera may move closer to your body to take the best quality images of certain bones.
A bone scan is generally devoid of side effects. The radiotracers are usually flushed out of your system within two days after the scan. The only adverse effect is reaction to the tracer (rare) and exposure to radiation.