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Lymphangiogram
Definition A lymphangiogram is a special x-ray of the lymph nodes and lymph vessels. Lymph nodes produce white blood cell (lymphocytes) that help fight infections. The lymph nodes also filter and trap cancer cells. The lymph nodes and vessels are not usually seen on a normal x-ray, so a dye or radioisotope (radioactive compound) is injected into the body to highlight the lymphatic areas. Alternative Names Lymphography; Lymphangiography How the test is performed The test is performed in a hospital radiology department or in the health care provider's office. If leg or arm swelling is being evaluated, you may be offered a sedative to help relax. You will be put in a specially constructed chair or on the x-ray table. The skin of each foot is cleansed, and a small amount of blue dye is injected between the toes into the webbing. Within 15 minutes, thin, bluish lines appear on the top of the foot. This identifies the lymphatics. Then, a local anesthetic is given and a small incision is made into one of the larger blue lines. A needle or catheter (a thin flexible tube) is inserted into a lymphatic channel in each foot, and a contrast medium is injected into each foot at a very slow rate (60 to 90 minutes for all the contrast medium to be injected). A fluoroscope (a special x-ray machine that projects the images on a TV monitor) is used to follow the dye as it spreads through the lymphatic system up the legs, into the groin, and along the back of the abdominal cavity. Once the contrast medium is injected, the catheter is removed, and the incisions are stitched and bandaged. X-rays are taken of the legs, pelvis, abdomen, and chest areas. The next day, another set of x-rays may be taken. If a site of cancer (breast or melanoma) is being studied to evaluate spreading, a mixture of blue dye and a radioactive tracer is injected next to the mass. Special cameras detect the spread of tracer along lymph channels to outlying nodes. During a biopsy, a blue dye or radioactive substance helps the surgeon see nearby areas (such as the arm pit for breast cancer) The dye or radioactivity can reveal the way the cancer has spread. How to prepare for the test Inform the health care provider if you are pregnant or you have bleeding problems. Also mention if you've had allergic reactions to x-ray contrast material or any iodine-containing substance. You must sign a consent form. You may be asked to not eat or drink for several hours before the test. You may wish to empty your bladder just before the test. If you are undergoing lymphangiography for sentinel lymph node biopsy (in breast cancer and melanoma), you will need to prepare for the operating room. A surgeon and anesthesiologist will discuss how to prepare for the procedure. How the test will feel There will be a brief sting from the needle and blue dye injected between the toes. There is another brief sting with the injection of the local anesthetic. There may be a feeling of pressure as the contrast medium is injected, and there may be some discomfort behind the knees and in the groin area. The incisions will be sore for a few days. The blue dye will color the urine and stool for about 48 hours. The skin and possibly the vision will take on a bluish cast temporarily. Why the test is performed A lymphangiogram is used with lymph node biopsy to determine the possible spread of cancer and the effectiveness of cancer therapy. Contrast dye and x-rays are used to help determine the cause of swelling in an arm or leg and check for parasitic (organisms that live on another) diseases. Additional conditions under which the test may be performed: - Hodgkin's lymphoma
- Non-Hodgkin's lymphoma
What abnormal results mean Enlarged nodes (swollen glands) that have a foamy appearance may indicate a lymphatic cancer. Nodes or parts of the nodes that do not fill with the contrast material may indicate a cancer spreading throughout the system. Blockage of the lymph vessels may be caused by tumor, infection, trauma, or previous lymphatic surgery. What the risks are There is a possibility of an reaction to the contrast medium. An infection is possible at the site of the injection. The dye or contrast material may cause a fever and inflammation of the lymph vessels. There is low radiation exposure. However, most experts feel that the risk of most x-rays is smaller than other risks we take every day. Pregnant women and children are more sensitive to the risks of the x-ray. Special considerations The contrast medium can stay in the nodes for up to 2 years. Review date: 5/3/2006 Reviewed By: Neil Grossman, MD, MetroWest Radiology Associates, Framingham, MA. Review provided by VeriMed Healthcare Network.
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