Vascular ultrasound imaging includes various noninvasive ultrasound procedures used to diagnose and evaluate pathology of the veins and arteries within the body. With stroke and diabetes being among the top ten causes of death, vascular ultrasound imaging is essential in evaluating atherosclerotic changes in the carotid arteries, clots, and peripheral vascular blockages.
Carotid duplex imaging, upper and lower extremity arterial studies, and flow studies are three of the most common types of studies performed. In all three types of studies, specialized technology using high frequency sound waves are used to visualize the vessels in the body.
Ultrasound professionals who perform Vascular ultrasound procedures are usually specialized in this particular area of concentration. Training usually consists of a two year program involving didactic and clinical study of ultrasound physics, pathophysiology of the vascular system and application. They are also required to obtain credentialing through either the American Registry for Diagnostic Medical Sonography (ARDMS) or Cardiovascular Credentialing International (CCI).
Neither credential is better than the other as they are both recognized by the American College of Cardiology. In either case, they are required to undergo continuing education and maintain their registry.
Although people often mistakenly refer to them as “technicians” the proper title for these professionals are vascular sonographers or vascular technologists. The difference being that a technician is only required to perform the test with no knowledge of theory or pathophysiology to make a preliminary diagnosis. Thus, it is impossible to be an technician in this field being that one has to be able to recognize not only disease but make clinical judgments required for evaluating and notifying the attending physician.
The most commonly ordered vascular imaging procedure is the carotid duplex exam. It involves the use of a high frequency hand held transducer to image the carotid arteries located on both the left and right side of the neck. The sonographer will use coupling medium also known as an ultrasound gel to direct the ultrasound and assist it in reflecting back to the transducer in order to produce and image of the inner lumen of the vessel and blood flow.
The sonographer is analyzing the presence and amount of calcification or plaque within the coronary arteries. They can also tell if there is the presence of a clot. Regardless of whether or not atherosclerotic changes are present, they will obtain measurements of the speed of blood flow within each component of the vessel. By law, the sonographer is not allowed to give you any results of the exam. It will be interpreted by a physician. The test is most often performed on people who are high risk for having a stroke, have had stroke like symptoms, or as a follow up to prior diagnosed disease.
Another frequently ordered vascular exam is a venous ultrasound. In this study, the sonographer uses the transducer to scan the veins of the leg for clots while compressing the vein to assess adequate blood flow within the vessel. It can be an exceptionally difficult examination to do, especially when there is excessive fat deposits in the leg or significantly toned muscles.
Ultrasound doesn’t travel well through dense tissue or bone. This test is performed primarily to detect a condition known as DVT or deep vein thrombosis in which clots form in the veins of the leg. If detected early enough, intervention can prevent detected clots from breaking off and traveling to the lungs. A clot that embolizes could possible result in dangerous condition called pulmonary embolism.
Another commonly performed examination is segmental arterial pressure measurement. Cuffs are attached to the legs to measure the pressures of blood flow in the arteries. Often limited vascular imaging with the ultrasound machine is performed to assess the blood flow within the arteries.
The test is especially useful in conditions such as atherosclerosis of the leg vessels which cause cramping in the legs during exercise. It is usually just a diagnostic exam which may lead to eventual invasive angiography testing to visualize and possibly correct problematic plaque in the vessels.
Vascular ultrasound imaging is an ever changing technology that has improved with advances in imaging techniques. It continues to remain as a first line diagnostic procedure where atherosclerotic disease continues to plague the population. It is safe, widely available and relatively inexpensive when compared to other diagnostic testing. Because of this it will remain one of the most preferred methods of diagnostic testing.