Some reasons your doctor may have ordered your vascular ultrasound:
- Symptoms of stroke can sometimes be explained by the discovery of a narrowing of one or more of the carotid arteries in your neck.
- The doctor heard a âwhooshing" sound over the neck with a stethoscope. Frequently a narrowing of more than 50% will cause the flowing blood to make a sound audible to your doctor. If the "bruit" (pronounced brew-ee) is due to a narrowing of the arteries directly leading to the brain ultrasound may spot this narrowing and determine the degree of narrowing or stenosis.
- Other arteries can be evaluated in the ultrasound laboratory. These include superficial blood vessels in the arms and legs.
After an arterial bypass procedure, the openness, or "patency" of an arterial bypass graft can be directly or indirectly assessed with ultrasound.
Some ultrasound laboratories attempt to detect narrowing of deeper vessels in the abdomen. Two examples are the renal arteries (arteries supplying the kidneys) and the superior mesenteric artery (supplying the intestines).
- Ultrasound is a very sensitive and non-invasive way to check the veins in the legs, to rule out the possibility of clots. Clots in leg veins can migrate centrally and lodge in the lungs (pulmonary embolism) and need to be treated.
How do I prepare for a vascular ultrasound?
- Studies of peripheral veins and arteries require no special preparation. Because cigarette smoking can cause blood vessels to constrict, smoking prior to an arterial study may be discouraged.
- Studies of the vessels deep in the abdomen are adversely affected by bowel activity and gas. For this reason, restriction of food and liquid intake is recommended for at least 6-8 hours prior to the vascular ultrasound.
- There is no special preparation for vascular ultrasound of the neck arteries (carotid ultrasound).
What will happen to me during my vascular ultrasound?
- You will meet a sonographer that will perform the examination. (In many cases the sonographer will have special training and be called an RVT, or Registered Vascular Technologist.)
- The sonographer will place the transducer, or ultrasound probe, over the artery or vein to be studied. To help the ultrasound beam penetrate the skin, a special gel is placed on the skin.
- The ultrasound image is formed on a screen, and the sonographer will occasionally stop to take a picture of the image. The sonographer may videotape the entire procedure.
- In many instances the sonographer may leave the room to show the pictures to the radiologist. The radiologist may even come into the examination room and perform additional scans, and discuss the findings with you.
- During the procedure, depending on the type of study, the sonographer may ask you to hold your breath, stop swallowing, or even elevate or compress a different part of the extremity (called "augmentation of flow" in the study of the deep venous system).