Definition of RBC nuclear scan:

An RBC nuclear scan uses small amounts of radioactive material to mark (tag) red blood cells (RBCs). Your body is then scanned to determine the location of the cells and to see how they move through the body.

See: Nuclear ventriculography

How the test is performed:

The exact procedure may vary slightly depending on the reason for the scan.

The RBCs are tagged with radioisotope in 1 of 2 ways.

The first method involves removing blood from a vein. The red blood cells are separated from the rest of the blood sample and then mixed with the radioactive material. The cells with the radioactive material are considered "tagged." A short time later the tagged RBCs are injected into one of your veins.

The second method involves an injection of medicine that will allow the radioactive material to attach to your red blood cells. The radioactive material is injected into a vein 15 or 20 minutes after you receive this medicine.

Scanning may be done immediately or after a delay. You will lie on a table underneath a special camera that detects the location and amount of radiation given off by the tagged cells.

A series of scans may be performed. The specific areas scanned depend on the reason for the test.

How to prepare for the test:

You must sign a consent form. You will wear a hospital gown. Remove jewelry or metallic objects before the scan.

How the test will feel:

When the needle is inserted to draw blood or to give the injection, some people feel moderate pain, while others feel only a prick or stinging sensation. Afterward, there may be some throbbing.

The x-rays and radioactive material are painless. Some people may have discomfort from lying on the hard table.

Why the test is performed:

This test is most often done to locate the site of bleeding in patients who have blood loss from the colon or other parts of the gastrointestinal tract.

A variation on this test, called a ventriculogram, may be performed to check heart function.