A liver scan, also known as a liver-spleen scan, is a diagnostic imaging procedure to evaluate the liver and spleen for suspected disease.
Purpose
A liver scan is performed to determine the size, configuration, relative function of the liver and spleen, and to detect space occupying lesions such as, cysts, an abscess, and tumors. Liver scans are indicated if a patient has abdominal pain, if a patient's liver enzymes (determined by blood tests) are abnormal, if the patient is jaundiced, and to detect and monitor metastatic disease. A liver scan may also be helpful in diagnosing specific disorders, by detecting features which are characteristic of a disorder, such as cirrhosis of the liver. This study may also be part of the battery of tests used to evaluate potential candidates for liver transplant.
Precautions
Women who are pregnant are cautioned against having this test unless the benefit of having the test out-wighs
the risks. If a woman is breast feeding, she will be required to stop for a specified period of time, depending on the dose given.
Description
This test is be performed in an out-patient facility or a hospital x-ray or nuclear medicine department. The patient is injected intravenously with a radioactive tracer, or radionuclide, that accumulates in certain cells of the liver, spleen, and bone marrow. Approximately 15 minutes after the injection, the patient is asked to lie down on a bed. A gamma camera or scintillation camera is positioned above the upper abdomen and may lightly touch the patient. It is important for the patient to lie quietly. Position changes and brief periods of breath holding may be required. The test usually takes approximately 30 minutes. Occasionally, a SPECT (Single Photon Emission Computed Tomography) study is indicated to further pinpoint an area of abnormality. The SPECT procedure is the same, but the camera will circle around the patient, in order to provide a cross sectional image of the liver.
Preparation
No physical preparation is required. The patient will be asked to remove metal objects from the area to be imaged. If the patient has had other recent nuclear scans, a waiting period may be necessary so that any residual radiation in the body will not interfere. The patients should understand that there is no danger of significant radioactive exposure to themselves or others. Only small amounts of radionuclide are used. The total amount of radiation absorbed is often less than the dose received from ordinary x rays.
Aftercare
No special aftercare is necessary.
Results
A normal scan will show a liver of normal size, shape, and position. It is expected that the liver will accumulate the radioactive tracer in a uniform fashion. Areas that appear absent may represent a cyst, abscess, or a tumor and therefore other imaging tests such as ultra-sound or CT may be required to assess the nature of the abnormality. Too much radioisotope in the spleen and bones compared to the liver, known as "colloid shift," can indicate portal hypertension or cirrhosis. Liver diseases such as hepatitis may also cause an abnormal scan, but is rarely diagnosed from the information revealed by this study alone. Again, other diagnostic tests are performed along with a liver scan to evaluate specific abnormalities and to arrive at a diagnosis.
Health care team roles
The injection and scan are performed by a nuclear medicine technologist, who will also obtain pertinent medical history from the patient and explain the test. The technologist is trained to handle radioactive materials, operate the scanner, and to process the data. The images are interpreted by a medical doctor who is a radiologist or nuclear medicine specialist. The patient received the results of the scan from their personal physician or doctor who ordered the test.
KEY TERMS
Radionuclide—A substance which emits radiation that can be detected by a scanner as the substance disintegrates.
BOOKS
Klingensmith III, M.D., Wm. C., Dennis Eshima, Ph.D., John Goddard, Ph.D. Nuclear Medicine Procedure Manual 2000-2001.
Vitti, Richard A., and Leon S. Malmud. "Gastrointestinal System." In Nuclear Medicine, edited by Donald R. Bernier, et al. St. Louis: Mosby, 1997.
PERIODICALS
Drane, Walter E. "Scintigraphic Techniques for Hepatic Imaging." Radiologic Clinics of North America, 36 (March 1998): 309-318.
