RBC (nuclear) scan
How the test is performed:
The exact procedure may vary slightly depending on the reason for the scan (the suspected problem).
The RBCs are tagged with radioisotope in 1 of 2 ways.
First, a sample of blood may be withdrawn from the person in the standard venipuncture method (similar to getting a sample for a blood test). In the laboratory, the RBCs are separated from the rest of the blood components and mixed with the radioisotope. A short time later these "tagged" RBCs are reinjected into a vein.
The second method involves injection of a medication that "sensitizes" the RBCs in the body, which is a complex chemical reaction that permits the RBCs to "accept" the radioisotope (attach the isotope to the cell membrane). The isotope is injected into a vein 15 or 20 minutes later.
Scanning may be performed immediately, after a delay, or a series of scans may be performed. The whole body or only particular locations may be scanned depending on the indications for the test. The person is asked to lie on a table while the scanner detects the location and amount of radiation emitted by the tagged RBCs.
How to prepare for the test:
You must sign a consent form. You will wear a hospital gown and asked to remove jewelry or metallic objects before the scan.
Infants and children:
The physical and psychological preparation you can provide for this or any test or procedure depends on your child's age, interests, previous experience, and level of trust. For specific information regarding how you can prepare your child, see the following topics as they correspond to your child's age:
How the test will feel:
There will be a sharp prick from the needles used for blood withdrawal and/or injection(s). You will not feel the radioisotope and the imaging, but the table may be cold or hard. You must lie still during the scan.
Why the test is performed:
Most often it is used to evaluate blood-flow patterns (nuclear ventriculography) or to locate the site of gastrointestinal bleeding. It may also be used to look for hemangioma (bruising) within the liver, and occasionally is used to evaluate the rate of blood loss in some anemias or to evaluate blood vessel obstructions.
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