Venograms, or Venography, are a subset of a larger class of x-ray exams called Angiography. Angiography in general is the study of the blood vessels in your body, with Venograms dealing strictly with the veins as opposed to the arteries, most commonly the veins in your legs, though other sets of veins can be examined. These studies are generally done when your doctor has reason to suspect a blood clot or other blockage of one of the more important vessels.

Since blood vessels in general do not show up on x-rays, a "dye" or contrast media must be injected into the veins being studied. This contrast medium is an "organic" iodine solution, meaning that the iodine is bound to compounds similar to those found in living organisms. You may hear the technologist talking about the contrast being "non-ionic". This refers to how the compound dissolves in water. If it breaks apart into two or three parts, it is normally referred to as ionic, if it does not, then it is non-ionic. Ionic contrasts are generally cheaper to make, but more people are allergic to them, so every facility I know of has gone to using only non-ionic x-ray dyes. While venograms can be done of just about any part of your body, they all are done using a similar style. So, since venograms of the leg are the most common, that is what I will describe here.

When doing a venogram of the leg, the radiologist and technologist doing your study will have you remove your pants, shoes, and socks, and put on a hospital gown. You will then be placed on an x-ray table that has been tilted up to between 30 and 45 degrees. Two tourniquets will be placed around your leg, one down near the ankle, and one up high on the thigh. These tourniquets are not to stop the blood flow in your leg, but rather to slow it down so that adequate x-rays may be obtained. The radiologist will then start an IV in your foot and slowly inject the contrast medium into it while the technologist quickly takes a series of films. The most common x-rays obtained are front and side views of the lower leg, the knee, and the thigh, with a front view of the hip finishing the series off. Another common version of this exam will have the technologist injecting the contrast through the IV in the foot while the radiologist films the study using fluoro (short for fluoroscopy). The advantage to this method is that if the facility doing your study has the proper digital equipment, they can do a "subtraction" study, where a computer uses a special "mask" or filter to remove from the x-ray images everything except the veins being studied and the outlines of the major bones that can then act as land marks to identify where any problem areas may lie.

Sometimes your surgeon may order a venogram or arteriogram done in the operating room during a "graft". In this case only one or two films will be shot, and the exam is done to check and make sure that the new vein or artery has been successfully grafted in place.

Perhaps the most common question I hear about this study is "How will they remove the dye from me after the exam?" Actually, we don't. You see, the contrast mediums we use for these studies are designed so that they will be filtered out of your blood stream by the kidneys within a relatively short period of time. So there is no need to worry about the contrast remaining in your body.

Another common question asked is "Will I experience any side effects from the x-ray dye?" This is definitely a reasonable fear, especially since the old ionic contrasts did have a relatively high incidence of producing allergic reactions. Still, even with the old dyes, only about 1 out of every 14,000 patients suffered a severe allergic reaction; and with the newer non-ionic contrasts, that number has been greatly reduced. Indeed, in one study of the one of the newer contrast, less than 1% of all patients had any reaction of any kind that could even be remotely considered severe. Generally the most you might experience is a slight flushing sensation and perhaps a slight "metallic" taste in your mouth.

[Home] [X-ray] [Cat Scan] [MRI] [Mammography] [Sign Guestbook,] [Take Survey] [Bio]