WBC (nuclear) scan

Alternative names:

leukocyte scan

What the risks are:

The risks are essentially the same risks as for X-rays (radiation) and blood tests or intravenous injections.

There is a very slight exposure to radiation from the radioisotope. The spleen normally receives the highest dose of radiation because white blood cells normally accumulate in the spleen. The radiation from these materials is very slight and the materials "decompose" (become no longer radioactive) in a very short time. Virtually all radioactivity is gone within 1 or 2 days. There are no documented cases of injury from exposure to radioisotopes. The scanner only detects radiation; it does not emit any radiation.

However, because of the slight radiation exposure, most nuclear scans (including WBC scan) are not recommended for women who are pregnant or breastfeeding (the radioisotope may be excreted in breast milk).

There is a minor risk that occurs whenever the body is penetrated (such as during blood sampling or injection of materials). This risk mainly involves the chance for infection or bleeding from the site. The risk for a WBC scan is no greater than when blood is sampled or material is injected into a vein for other reasons.

Extremely rarely, a person may experience an allergic reaction to the radioisotope. This may include anaphylaxis if the person is extremely sensitive to the substance.

Special considerations:

The long delay before the person can be scanned may be undesirable for critically ill people.

Other tests (such as CT scan or ultrasound) may be required to confirm the presence of inflammation or infection indicated by abnormal WBC scan.

False-negative results can theoretically occur as a consequence of antibiotic usage or chronic infection. Infection in the liver or spleen can be missed because of normal WBC accumulation in these organs.

False-positive results can occur from many causes, including (but not limited to) bleeding, the presence of indwelling tubes or catheters, and skin wounds (such as surgical incisions). WBC accumulations in the lungs does not necessarily indicate an infection in the lungs.