Bone Nuclear Medicine Scan

A radiotracer (bone-seeking radionuclide) is injected into the bloodstream through a peripheral vein. As it decays, the radiotracer emits gamma radiation, which is detected by a camera that slowly scans your body. The camera is used to capture images to be used to determine how much of the radiotracer collects in the bones.

If a bone scan is performed to evaluate possible fracture or infection, images will be performed shortly after the radiotracer injection, as well as after a 3-hour delay, when the tracer has collected in the bones. This is called a 3-phase bone scan.

To evaluate metastatic bone disease, images are obtained only after the 3-hour delay. Information from the camera is recorded in a computer, which then processes the data and creates an image.

The scanning part of the test will last about an hour and may require moving to various positions.

Why have a bone nuclear medicine scan

Bone scans are most frequently ordered to check whether a cancer which originated elsewhere has spread to the bones. Cancers which begin in the breasts, kidneys, lungs, prostate, thyroid, or urinary bladder are most likely to spread, or metastasize, to the bones. If metastases are found, periodic bone scans may be ordered to see if therapy is effective against a cancer.

Some cancers arise in bone. These are called primary bone cancers. When an abnormality is found on an x ray of a bone, a bone scan may be helpful in deciding if it is a primary bone cancer, or a non-cancerous (benign) condition.

Infection in the bone (osteomyelitis) can be detected or confirmed by a bone scan, often days or weeks before an x ray would reveal it. Bone scans are useful in diagnosing early arthritic changes, and monitoring both the progression of the disease and the effectiveness of treatment. Unexplained pain may be evaluated with a bone scan, because it can demonstrate fractures which are difficult to detect on x ray. Bone scans can be used to see if artificial joints have loosened or become infected. Suspected child abuse may be evaluated with a bone scan, due to its ability to see an overall pattern of repeated trauma. Abnormalities caused by altered circulation to the bone may be diagnosed with a bone scan.

Precautions of bone nuclear medicine scan

Women who are pregnant or breast feeding should not have this test. A patient who is unable to remain still for an extended period of time may require sedation for a bone scan.

Information about bone nuclear medicine scan

This test is performed in a radiology facility, either in a hospital department or an outpatient x-ray center. The patient usually sits or lies down while a radioactive substance is injected through a vein in the arm. For a bone scan, the radionuclide used is specifically chosen to accumulate in the bone. The patient then waits from three to four hours, for the substance to collect within the skeletal system. During this time, he or she will be instructed to drink several glasses of water. Patients are free to get up and move around as they desire during this waiting time, and should urinate frequently. Just before the scanning begins, the patient should empty his or her bladder again. This ensures that a lot of radioactive material is not concentrated in the urinary bladder, which could obscure part of the pelvic bones.

During the scan, the patient lies on his or her back on a table, but may be repositioned to the stomach or side during the study. It is important for the patient not to move, except when directed to by the technologist.

The radionuclide scanner, sometimes called a gamma camera, or scintillation camera, is positioned against the body part to be examined. Either the camera, the table, or both, may change position during the study. For a total body bone scan, the patient is scanned from head to foot, over a period of 30-60 minutes. Patients should experience no discomfort from this examination.

A special kind of bone scan, called a SPECT (Single Photon Emission Computed Tomography) scan may be added, to study a particular part of the body in more detail. Suspected diseases of the hips, lower back, or jaw are often evaluated using this study. It usually takes an additional 30-45 minutes. The camera circles completely around the area in question or multiple cameras are used to create a cross-sectional image. This helps pinpoint the location of the abnormality being evaluated.

Another variation is called a three-phase, or three-stage, bone scan. The procedure is the same, except the scanning takes place immediately after the radioactive substance is injected, approximately 20 minutes after the injection, then two to four hours later.

Preparing for a bone nuclear medicine scan

Some specialized blood studies should be drawn before this study is begun. Jewelry or metallic objects need to be removed. No other special physical preparation is required.

The patient should understand that there is no danger of radioactive exposure to themselves or others, as only small amounts of the radioisotope are used. The total dose of radiation absorbed is minimal, often less than the amount received from ordinary x rays. The radionuclide scanner does not emit any radiation at all, but detects and records it from the patient.

Aftercare of Bone nuclear medicine scan

Fluids are encouraged after the scan to aid in the excretion of the radioisotope. It is almost completely eliminated from the body within 24 hours.

Normal results

Normal distribution areas appear uniform and gray throughout all the bones in your body.

Abnormal results