Diagnostics
Bone scan (Bone Scintigraphy)
What is a bone scan?
Who conducts bone scans and where they are conducted?
Why is a bone scan done?
A bone scan can be helpful in identifying the underlying cause of unexplained bone pain. The test can detect variations in bone metabolism throughout the body with the use of a radioactive tracer. This comprehensive scan of the skeleton aids in the diagnosis of various bone disorders, including:
- Fractures
- Arthritis
- Paget’s disease of bone
- Bone cancer (primary bone cancer)
- Metastatic bone cancer (cancer that has spread to the bone from another site)
- Infections in the joints, joint replacements, or bones
The sensitivity of the bone scan allows for the detection and evaluation of these diverse bone conditions, assisting doctors in formulating an accurate diagnosis and appropriate treatment plan.
How does a bone scan work?
Before the procedure
Patients may be asked to provide a list of medications they are currently taking, including
over-the-counter drugs and supplements. Certain medications can interfere with the bone scan, so the doctor will assess if any adjustments are necessary. In most cases, fasting is not required. Patients should remove any metal objects or clothing with metal components, such as jewelry, belts, and underwire bras, as they can interfere with the scan’s quality. Patients should inform the doctor if they are pregnant or breastfeeding, as special precautions may be necessary. Radiation exposure during pregnancy should be minimized.
Patients should wear comfortable clothing without metal parts or fasteners, as they may be asked to change into a gown for the scan.
During the procedure
A bone scan involves two parts: the injection and the actual scan.
Injection:
A small amount of a radioactive tracer is injected into a vein in the arm. This tracer is absorbed by the bones and emits gamma rays. Some immediate images may be taken, but the main images are usually captured 1 to 3 hours later. After the injection, there is typically a waiting period of about 1-3 hours. During this time, patients are advised to drink fluids and urinate frequently to help remove any excess tracer from the body.
Scan:
Patients are positioned on an examination table, and a gamma camera or scanner is used to capture images of the bones. Multiple images may be taken at different angles.
Patients are required to lie still during the imaging process to ensure clear and accurate images. Any movement can lead to blurriness in the pictures.
The imaging process itself may take 30 minutes to an hour or more, depending on the extent of the scan and the specific areas being examined. The amount of radiation exposure during a bone scan is relatively low and considered safe.
After the Test
After the bone scan procedure, it is recommended to get up from the scanner table slowly to avoid potential dizziness or lightheadedness that may occur from lying flat during the procedure. Taking time and moving gradually can help prevent any discomfort or imbalance.
A bone scan generally has no side effects and requires no specific follow-up care. Drinking plenty of fluids is advised to help eliminate any remaining tracer from the body. The radioactivity from the tracers is typically eliminated within two days after the scan.
The images captured during the scan are analyzed by a nuclear medicine physician, who interprets the results.
The results are then provided to the referring doctor, who will discuss them with the patient.
References
- Bone scan. Available from: https://www.hopkinsmedicine.org/health/treatment-tests-and-therapies/bone-scan
- Mayo Clinic. Bone scan. Available from: https://www.mayoclinic.org/tests-procedures/bone-scan/about/pac-20393136#:~:text=A%20bone%20scan%20is%20a,as%20bones%20inside%20the%20body
- Bone Scan. Available from: https://www.cancer.net/navigating-cancer-care/diagnosing-cancer/tests-and-procedures/bone-scan
