Liver-spleen scan

Definition

A liver-spleen scan is a nuclear medicine procedure that uses very small amounts of radioactive material to create an image of the liver and spleen.

Purpose

A liver-spleen scan is done for a variety of reasons. In some cases the scan is done to help diagnose a disease or condition of the liver or spleen when symptoms, health history , or other tests indicate that such a disease or condition may exist. Another frequent use of the liver-spleen scan is to determine if cancer has metastized, or spread, from another part of the body to the liver or spleen. It is also sometimes performed when there is abdominal pain in the area of the liver with no apparent cause, or when there has been a traumatic injury to the abdomen and there is the possibility of injury to the liver or spleen.

In addition to helping diagnose a variety of diseases and conditions, a liver-spleen scan can also be used to help determine how well a treatment plan is working. It can be used to help determine if a tumor in the area is growing or shrinking, or to help determine how well the liver or spleen is functioning. It is also sometimes used to help determine if an individual is a good candidate for liver transplantation.

Precautions

Women who are pregnant should not undergo a liver-spleen scan. Although the very small amount of radioactive material is safe for adults, it is not

QUESTIONS TO ASK YOUR DOCTOR

• If my scan shows abnormalities what is the next step?
• How likely is a false positive? A false negative?
• What other diagnostic or imaging procedures might be appropriate for me?

completely clear what effects it could have on a developing fetus. Women who are pregnant should use alternative imaging technologies or schedule the scan for after the birth of the baby if at all possible. Women who are breastfeeding should not undergo a liver-spleen scan because the radioactive tracer used in the scan can be passed to a nursing infant in breast milk. Women who are breastfeeding may be able to undergo a liver-spleen scan if they make alternative feeding arrangements, such as storing breast milk or using formula, for the day of the scan and a few days following the scan until the radioactive material has been excreted fully.

Barium and bismuth can interfere with the clarity of the image of the liver and spleen. Barium is not common but is sometimes used as a contrast material in other imaging procedures. Bismuth is sold as a remedy for indigestion, heartburn , upset stomach, and diarrhea under a variety of brand names including Pepto-Bismol. Because these can affect the quality of the liver and spleen images, imaging procedures using barium should be scheduled for after the liver-spleen scan, or at least four days prior to the scan. Medicines containing bismuth should not be taken for at least four days before the scan.

Description

A liver-spleen scan uses a very small amount of radioactive material, often called a radioactive trace or simple trace, to create an image of the liver and spleen. The radioactive material is injected into the patient, usually in the arm. The trace then circulates in the blood and is absorbed into the liver. The radioactive trace gives off very small amounts of gamma radiation, which are picked up by a specialized camera called a gamma camera. The camera is attached to a computer to which it sends the information about the gamma radiation detected. The computer then creates an image of the liver and spleen using this information.

The first step of the liver-spleen scan is the injection of the radioactive trace. Sometime the patient is asked to wait after the trace is injected to allow the trace to circulate and be absorbed. Often however the scan is begun very quickly after the injection. During the scan the patient is asked to lie on a table. The gamma camera is mounted on an arm that can move around the table to take images at different angles. It is necessary that the patient remain completely still during the scan, and he or she may be asked to hold his or her breath briefly to help get a clear image.

The patient may be asked to change positions one more times during the scan so that the image can be taken from a variety of angles. In some cases images will be taken, the patient will be asked to wait a certain amount of time, and then additional images will be taken. In general the scan itself, not including any waiting time, usually takes about an hour. The patient may be asked to drink water after the injection to help facilitate removal of any trace not absorbed by the liver or spleen from the body.

Preparation

Individuals undergoing a liver-spleen scan can eat and drink normally before the procedure. Women who are breastfeeding may be asked to switch to an alternative method of feeding before the procedure. Before the scan itself the individual will be asked to remove any metal jewelry or accessories, and may be asked to change into a gown.

Aftercare

No special aftercare is required for most people.

Women who are breast feeding should not resume breast feeding after the procedure until at least a few days after the procedure so that the radioactive material has time to leave their body.

Complications

No complications are expected from a liver-spleen scan for most people. There is always a small risk of infection, bruising , swelling, or bleeding when an injection is given. Some may be experience minor stiffness or soreness from lying in one position for a long period of time in one position. In extremely rare cases an allergic reaction to the injected radioactive tracer is possible.

Results

A normal liver-spleen scan shows a liver and spleen that are of normal sizes and that both absorb roughly the same amount of the tracer in all areas. A diagnosis is not made solely on the basis of a liver-spleen scan, but rather on the combination of information about symptoms, health history, and the results of previous diagnostic test or imaging procedures. Abnormal liver-spleen scan results show an enlarged liver or spleen, or uneven amounts of trace absorption. A variety of different diseases and conditions can cause the enlargement of the liver and spleen. The liver or spleen may also appear to be misshapen or abnormally formed. This may result from a tumor growing nearby that has grown large enough to push against the liver or spleen and cause it to change shape.

KEY TERMS

gamma radiation —High-energy, short wavelength electromagnetic radiation emitted by the nuclei of an excited atom.

If the spleen absorbs more tracer than the liver, this may be an indication of portal hypertension , a condition in which the blood pressure within the liver itself is elevated. Areas of higher than normal or lower than normal absorption of the radioactive tracer can be caused by a variety of diseases and conditions including cirrhosis , hepatitis , cancer, infection, injury, or abscess.

Caregiver concerns

A doctor determines the need for a liver-spleen scan based on the patient's symptoms, health history, and the results of any other tests. Many members of the staff of the nuclear medicine center may be involved with the patient. A nurse, nuclear medicine specialist, or the doctor who ordered the procedure will explain the procedure to the patient and address any questions or concerns that he or she might have. A nurse injects the patient with the radioactive tracer. The scan itself is performed by a nuclear medicine technician or technologist who operates the camera and positions the patient as necessary. The images resulting fromthe scan are interpreted by a radiologist or a doctor specializing in nuclear medicine. The results of the scan are then given to the doctor who ordered the scan. The doctor then makes a diagnosis based on the results or determines which additional tests or procedures are indicated.

Resources

BOOKS

Brant, William E. and Clyde A. Helms. Fundamentals of Diagnostic Radiology, 3rd Ed. Philadelphia: Lippincott Williams & Wilkins, 2007.

M.F. Reiser, et al, eds. Screening and Preventive Diagnosis with Radiological Imaging. New York: Springer, 2007.

PERIODICALS

Brar, Harinder S., John F. Sisley, Robert H. Johnson Jr. and Michael J. Edwards. “Value of Preoperative Bone and Liver Scans and Alkaline Phosphatase in the Evaluation of Breast Cancer Patients.” American Journal of Surgery 165.n2 (Feb 1993): 221-225.

“Trends in liver cirrhosis research.” SciTech Book News (Dec 2007).

ORGANIZATIONS

Hepatitis Foundation International, 504 Blick Drive, Silver Spring, MD, 20904, 800-891-0707, http://www.hepfi.org/.

Robert Bockstiegel