Venography is a medical imaging technique that is used to examine the veins of the body. It is commonly used on the lower legs, although venography can be utilized to look at other areas of the body as well. This test is typically ordered when a doctor suspects that a patient may have a venous obstruction and it can also be used to evaluate people with chronic cardiovascular conditions or to identify a vein that will be suitable for grafting.
In a venography study, a contrast agent is injected into the area of interest. The patient is positioned under a fluoroscope and a series of images are taken as the contrast agent moves through the veins. In a healthy patient, the radio-opaque dye will move smoothly and evenly through the veins. If there is an obstruction, it will be highlighted on the fluoroscope. Still images can be taken as well, if necessary.
This is an invasive test, and there are some risks for the patient. Venography is not suitable for people who are pregnant or people who have experienced allergic reactions to iodine and contrast media in the past. It can be uncomfortable both because the patient needs to lie still and because the contrast material can create a burning or stinging sensation in the veins. Patient are also required to fast before the test and this can be a hardship.
One of the most common reasons to request this test is due to concern that there is a blood clot in the legs. Deep vein thrombosis, as it is known, can be difficult to identify by other means, but a venogram will make the clot highly visible, ensuring that the patient is diagnosed and can receive treatment. The test can also be used to follow up on a patient who has chronic problems or it may be ordered in advance of a surgery where a vein will be needed for grafting, to allow the surgeon to identify a good vein to harvest.
After a venography study is complete, patients may want to rest for the remainder of the day. The anesthetics and other medications used to make the patient comfortable can leave the patient with a disoriented or groggy feeling. It is also advisable to drink ample amounts of water to help the kidneys flush the contrast agent out. If patients experience symptoms like cramping and pain after a venography study, they should contact a doctor immediately.
