What is a bone scan?
A bone scan is a specialized radiology technique to evaluate the skeleton's bones. It is performed to identify areas of bone with physical and chemical alterations. A bone scan may also be used to monitor the progression of certain conditions' treatments.
Bone scans are a form of nuclear radiology. This indicates that a trace quantity of a radioactive substance is used to aid in examining the bones. The radioactive substance, known as a radionuclide or tracer, will accumulate in areas of abnormal physical and chemical change within the bone tissue.
Gamma radiation is the form of radiation emitted by the radionuclide. A scanner detects the gamma radiation and processes the information into an image of the bones.
The areas where the radionuclide collects are referred to as "hot spots." They may indicate the presence of conditions such as arthritis, malignant (cancerous) bone tumours, metastatic bone cancer (cancer that has spread from another site, such as the lungs), bone infections, bone trauma not visible on standard X-rays, and other bone conditions.
Why might I need a bone scan?
The primary purpose of bone scans is to detect the spread of metastatic cancer. Due to the rapid multiplication of cancer cells, they will appear as a hot location on a bone scan. This results from elevated bone metabolism and bone repair near cancer cells. Bone scans may also assess the efficacy of the treatment by staging the malignancy before and after treatment.
Other reasons for undergoing a bone scan procedure may include, but are not limited to:
- Assessing bone trauma in cases where standard X-rays do not reveal trauma.
- To detect difficult-to-find fractures
- To determine the age of fractures
- To diagnose or evaluate bone infections (osteomyelitis).
- Evaluation of unexplained bone pain
- To detect conditions such as arthritis, benign bone tumours, Paget's disease (a bone disorder that typically affects people over the age of 50 and is characterized by the thickening and softening of the bones and the curvature of the long bones), and avascular necrosis (death of bone tissue due to loss of blood supply to the bones)
There may be additional reasons why your doctor suggests a bone scan.
What risks are associated with bone scans?
Due to the minute quantity of radionuclide injected into your vein during the procedure, no precautions against radioactive exposure are necessary. The injection of the tracer may result in a minor degree of discomfort. Allergic reactions to the tracer are uncommon, but they are possible.
Patients allergic or sensitive to medicines, contrast dyes, or latex should inform their physician.
Due to the risk of injury to the foetus from a bone scan, you should inform your healthcare provider if you are pregnant or suspect that you may be pregnant. Due to the potential for breast milk contamination with the tracer, you should notify your healthcare provider if you are lactating or breastfeeding.
There may be additional hazards based on your particular medical condition. Discuss any concerns with your physician before the procedure.
How do I prepare for a bone scan?
- Precautions: If you are pregnant or suspect you may be pregnant, please consult your physician before scheduling the exam. We'll discuss additional options with you and your physician.
- Breastfeeding: If you are lactating, you should inform your healthcare provider due to the potential for tracer contamination of breast milk.
- Clothing: You might be required to change into a patient robe. You will be provided with a robe. Lockers are available for securing personal possessions. Please remove all jewellery and valuables and leave them at home.
- Eat/Drink: In most cases, no preparation, such as fasting or sedation, is necessary before a bone scan.
- Allergies: notify the radiologist or the technologist if you are allergic to medications, contrast dyes, or iodine. The radiotracer injection may result in minor discomfort. Rare allergic reactions to the radiotracer are possible.
What you can expect
In addition to the scan, a bone scan procedure involves an injection.
The Injection
Tracers are radioactive substances that are injected into a vein in the forearm or arm. Depending on the reason for the scan, the quantity of time between the injection and scan varies.
Some images may be captured right after the injection. The primary pictures, however, are captured two to four hours later to enable the tracer to circulate and be absorbed by the bones. While you wait, you may be asked to consume several glasses of water.
Before the scan, you will likely be requested to void your bladder to remove any unabsorbed tracer.
The scan
You will remain immobile on a table while an arm-like apparatus carrying a tracer-sensitive camera moves back and forth over your body. The actual scan may take up to an hour. The procedure is without pain.
Your doctor may prescribe a three-phase bone scan consisting of images captured at different times. Several pictures are captured during the tracer injection, immediately after the injection, and 3 to 5 hours later.
You may be required to sign a consent form authorizing the administration of the test. Carefully read the paper and ask inquiries if something needs to be clarified.
Usually, no preparation, such as fasting or sedation, is necessary before a bone scan.
Inform the radiologist or technologist if you are allergic to medications, contrast dyes, or iodine.
Notify your healthcare provider if you are pregnant or suspect you may be pregnant.
Depending on your medical condition, your doctor may prescribe a different medication.
