Bone Scintigraphy
Bone scintigraphy involves observing the structure of bones using a small amount of radiation along with a device that generates images from various angles. This nuclear medicine test can diagnose conditions that other procedures may not detect.
General Description
Bone scintigraphy, or bone scintigraphy imaging, is a nuclear medicine procedure used to obtain images of the bones, which helps diagnose or monitor the progression of certain diseases affecting the skeleton.
To assess the bone morphology with scintigraphy, a radiopharmaceutical is administered. Cells undergoing change absorb this substance in higher amounts, making it easier to detect accelerated structural alterations. The amount of radiation used is very small, so no side effects occur. In the case of bone scintigraphy, colloids of albumin and technetium, nanocolloids, technetium medronate, technetium oxydronate, or technetium propanedicarboxyphosphonate are commonly used.
When is it indicated?
Bone scintigraphy is a tool used to diagnose various bone diseases in patients where other tests have failed to determine the cause of their symptoms:
- Paget’s disease.
- Arthritis.
- Infections.
- Fractures.
- Bone cancer (osteosarcoma).
- Metastasis (advanced-stage tumors originating in other organs and spreading to the bones).
- Unexplained pain.
How is it performed?
The first step in performing a bone scintigraphy is to administer the radiopharmaceutical. It is typically injected into one of the veins in the arm. Before capturing the images, it’s necessary to wait between two and four hours, the time it takes for the substance to distribute throughout the body.
Next, the patient is placed on a table and inserted into a tube-shaped device (gamma camera) that rotates around the body to capture images from various angles. In cases where the acquisition heads are not mobile, the specialist will ask the patient to change positions during the procedure.
Risks
The radiation used in bone scintigraphy is very low, so it doesn’t pose a health risk. In very rare cases, the radiopharmaceutical may trigger an allergic reaction, usually mild (rash and itching).
The radiation dose safe for an adult may not be safe for a child or fetus, so this test is not recommended for pregnant women, and contact with children and pregnant women should be avoided afterward. Lactating mothers should discard milk produced within 48 hours after receiving the radiotracer.
What to expect from a bone scintigraphy
This is an outpatient procedure that doesn’t require hospitalization or recovery time afterward. Patients can resume their daily activities once the test is completed.
Upon arrival, the patient must sign an informed consent form for the bone scintigraphy. Afterward, the radiotracer is injected, which may cause discomfort or a sensation of heat or cold in the veins of the arm as the substance ascends. Although the imaging device is a narrow tube that might cause anxiety or claustrophobia in some patients, the technique is not painful. It may be uncomfortable to remain as still as possible during the procedure.
The wait between the radiopharmaceutical injection and the start of the test may feel long. The procedure takes between 10 and 30 minutes. Results are typically available a few days after the test.
To help expel the radioactive substance from the body, it’s advisable to drink plenty of water on the day of the scintigraphy.
Specialties that request a bone scintigraphy
Bone scintigraphy is usually performed by nuclear medicine doctors, often upon the request of an orthopedic surgeon or oncologist.
How to prepare
Bone scintigraphy does not require specific preparation. Fasting is not necessary, and, unless instructed otherwise by the doctor, regular medication can be taken.
It is advisable to wear comfortable clothing and avoid jewelry, as metallic objects are not allowed in the room with the gamma camera. Since waiting times are long, it is recommended to prepare an activity to pass the time.
