Vascular Ultrasound – Exams

What Type of Vascular Ultrasound Evaluations are Performed?

Cerebrovascular Evaluation

Cerebrovascular disease is a group of brain dysfunctions related to disease of blood vessels supplying the brain. Hypertension is the most important cause that damages the blood vessel lining endothelium, exposing the underlying collagen where platelets aggregate. Sustained hypertension permanently changes the architecture of the blood vessels making them narrow, stiff, deformed and uneven which are more vulnerable to fluctuations of blood pressure.

A cerebrovascular evaluation uses noninvasive ultrasound to examine the blood flow to the brain. As blood leaves the heart via the aorta, it circulates up through the carotid and vertebral arteries on each side of the neck to the head.

During a cerebrovascular evaluation the technologist will pass a transducer (probe) over your neck. The test includes examination of the subclavian, vertebral, internal and external carotid arteries. This noninvasive test is used to detect and quantify the degree of obstruction, which may have formed in any of the arteries listed above from a build-up of cholesterol or fatty material called plaque. This build-up, referred to as atherosclerosis, increases an individual’s risk for stroke.

Length of exam: 45 min – 60 min

Symptoms: Stroke, transient ischemic attack, bruit, syncope, abnormal gait, limb paralysis, paresthesia, vertigo, difficulty speaking, sudden visual loss, difficulty swallowing, etc. Preparation: None

Carotid Intima Media Thickness

1999 study published in the New England Journal of Medicine concluded that increases in the thickness of the intimal and medial layers of the carotid artery are directly associated with an increased risk of heart attack and stroke. By measuring the thickness of the patient’s arteries, we are given a glimpse of his/her overall risk of developing cardiovascular disease. Carotid intima-media thickness (IMT) exams have also been found to be useful at tracking changes in the carotid wall thickness after medication or lifestyle changes have been prescribed. Multiple studies have demonstrated a regression in the IMT over time after the implementation of cholesterol-lowering medication.

In an effort to reduce the number of cardiovascular events and promote prevention within the community, Northwest Vascular Diagnostics is pleased to be offering carotid IMT exams. All outpatients who are referred for a carotid ultrasound will now receive a carotid IMT measurement at no additional cost.

Upper Extremity Arterial Evaluation

Arterial segmental pressure and waveform evaluations are performed to evaluate the upper extremity arteries to determine the presence, severity, and location of arterial occlusive disease or absence of pathology. Duplex ultrasonography will be performed if clinically indicated. Thoracic Outlet Syndrome, Raynauds and Allen’s tests are specialty exams that are performed and are listed in the following paragraphs.

Length of exam: 45 – 60 min

Symptoms: Arterial insufficiency, limb ischemia/digital ischemia. Preparations: None

Lower Extremity Arterial Evaluation

Some of the common indications for performance of lower extremity arterial duplex imaging include:

  • Assessment of patients with known arterial disease
  • Pre-procedure assessment for planning of an intervention
  • Follow-up to determine technical adequacy surgical intervention, i.e. post angioplasty and/or stent placement
  • Evaluation of aneurysm, pseudoaneurysm, arterial-venous fistula
  • Evaluation of arterial trauma

The initial test to identify disease or normality of the arteries in the lower extremity is an ankle-brachial index (ABI). This is a physiologic test that identifies blood pressures and arterial waveforms in both lower extremities and compares them to the brachial blood pressures.

If the physiologic test is determined to be abnormal, a second test to evaluate arterial disease will be performed. This second test will include duplex imaging of the arteries in the lower extremities.

Duplex ultrasonography of the lower extremity arteries is performed to provide an overview of the location, extent and severity of vascular disease. The ultrasound evaluation can be performed from the abdominal aorta through the tibial vessels and extended into the foot in order to facilitate clinical management decisions.

Length of exam: 45 – 60 min

Symptoms: Claudication, ischemic rest pain, arterial ulcerations. Preparations: None

Upper and Lower Extremity Vein Evaluation

Deep vein thrombosis (DVT) is a condition in which a blood clot forms in one of the deep veins in the body. This condition is most commonly found in the lower leg or thigh, however it can also form in the upper extremities. One of the major complications of lower extremity DVT is the traveling of the blood clot to the lungs (Pulmonary Embolism), brain, or heart, leading to severe damage.

Some of the major risk factors for developing a DVT include sitting for a long period of time (long plane or car trips), bedrest, recent surgery, hormone medications, oral contraceptives, cigarette smoking, obesity, hypercoagulability disorders, cancerous tumors, and pregnancy.

Lower Extremity:

A duplex ultrasound of the deep veins in the lower extremities is performed to determine the presence or absence of deep vein thrombosis (DVT) using compression and augmentation maneuvers. The superficial veins are also examined to determine patency and valve competence.

Upper Extremity:

A duplex ultrasound of the deep veins in the upper extremities is performed to determine the presence or absence of deep vein thrombosis (DVT) using compression and augmentation maneuvers. The superficial veins are also evaluated for patency.

Length of exam: 45 – 60 min

Symptoms: Pain in limb, limb swelling, superficial mass/lump, shortness of breath, pulmonary embolism, chest pain with respirations, ulcer/skin changes. Preparation: None


Varicose Veins

The common indications for varicose veins are symptoms which interfere with daily life in spite of conservative treatments. Varicose veins can be unsightly and/or debilitating. With the current advancements in varicose vein treatment, varicose vein surgery has become an easy outpatient procedure.

After a complete and delicate physical examination, noninvasive vascular tests should be done to evaluate if the surgery should be performed and what approach should be taken.

Venous duplex mapping is the most important non invasive study for varicose vein ablation. To precisely diagnosis incompetence in the great saphenous vein or short saphenous vein, abnormal reflux must be identified using ultrasound. After the complete venous mapping of the varicose vein has been established, the definite surgical planning can be made.

Length of exam: 45 – 60 min

Symptoms: Pain/heaviness/tiredness/aching in leg(s), bulging/spider veins, limb swelling, ulcerations/skin changes.

Preparations: None

Vein Mapping

Upper Extremity Vein Mapping: The superficial veins in the upper extremities are evaluated for size and patency to determine if they are adequate for use as hemodialysis access or coronary artery bypass grafts.

Lower Extremity Vein Mapping: The superficial veins in the lower extremities are evaluated for size and patency to determine if they are adequate for use as lower extremity or coronary artery bypass grafts.

Length of exam: 45 – 60 min

Symptoms: None, pre-operative examination

Preparations: None

Thoracic Outlet Syndrome

Thoracic outlet syndrome is a combination of pain in the neck and shoulder, numbness and tingling of the fingers, and a weak grip. The thoracic outlet is the area between the rib cage and collar bone.

Thoracic outlet syndrome is a rare condition caused by compression of blood vessels and nerves in the area of the clavicle (collar bone). This compression usually is caused by the presence of an extra cervical rib (above the first rib) or an abnormal tight fibrous band connecting the spinal vertebra to the rib.

Ultrasonography is readily available and relatively inexpensive, and it can be performed in both arterial and venous thoracic outlet syndrome.

Length of exam: 45 – 60 min

Symptoms: Numbness/pain in arm(s) while in compromising positions.

Preparations: None

Raynauds

Raynauds syndrome is a rare disorder that affects the arteries in the digits of either the upper or lower extremities.

The disorder is marked by brief episodes of vasospasm (narrowing of the blood vessels) following exposure to cold temperatures. Vasospasm of the arteries reduces blood flow to the fingers and toes.

Physiological tests are performed to determine the presence or absence of this disorder.

Length of exam: 45 – 60 min

Symptoms: Numb/cold/painful digit(s), color changes in digit(s) in response to cold or stress.

Preparations: None

Dialysis Access Graft

Healthy kidneys clean the blood by removing excess fluid, minerals, and wastes. They also make hormones that keep bones strong and the blood healthy. When the kidneys fail, harmful wastes build up in the body, blood pressure may rise, and the body may retain excess fluid and not make enough red blood cells.

When this happens, treatment is needed to replace the work of the failed kidneys.   This treatment is called dialysis.   Dialysis (or hemodialysis) performs the normal duties of the kidneys including regulation and filtration.   When on hemodialysis, a vascular access is used as a site from which the blood is removed and returned.   Whether the vascular access method used is an arteriovenous fistula, an arteriovenous graft, or a venous catheter for temporary use, it is important to have it routinely examined.

Color Doppler ultrasound is a non-invasive technique for the assessment of vascular accesses. For those individuals with hemodialysis access grafts, duplex ultrasound provides a safe and effective way to evaluate the graft for patency, maturity, and flow characteristics.

Length of exam: 45 – 60 min

Symptoms: None, follow-up examination

Preparations: None

Radial/Palmar Arch Exam

When using the radial artery as a coronary artery bypass graft, it is essential to evaluate the artery for patency as well as to ensure that there is a complete palmar arch. The palmar arch is an artery that feeds the hand and digits. This artery is needed to ensure that the hand and digits get an adequate amount of blood and nutrients.

Before harvesting the radial artery, a duplex ultrasound is performed to evaluate the artery for patency and size. Next, a physiologic test is performed to determine if there is a complete palmar arch, as well, to make sure the hand and digits are receiving the vital nutrients and blood.

Length of exam: 45 – 60 min

Symptoms: None, pre-operative examination

Preparations: None

Bypass Grafts

An arterial bypass graft is the most durable means to treat severe, peripheral artery disease when the blockage is below the level of the groin. Bypass grafts offer many advantages for patients with peripheral arterial disease (PAD). They can be used for extensive arterial blockages as well as blockages involving smaller arteries below the knee.

For these grafts to work, however, there must be sufficient flow through the graft. Vascular laboratory testing is regularly used to performed to track the patency and flow characteristics of the graft.

In addition to a complete duplex scan of the graft and the inflow and outflow arteries, ankle and arm blood pressures will be measured using inflatable cuffs and an ultrasound Doppler flow detector.

Length of exam: 45 – 60 min

Symptoms: None, follow-up examination

Preparations: None

Renal

Hypertension affects up to 65 million adults in the United States . A small subset of these patients have renovascular hypertension due to obstruction of the renal arteries. Fortunately, this type of hypertension can be corrected with treatment of the offending renal artery stenosis. Many hypertensive patients are referred for duplex ultrasound to screen for the presence of renal artery stenosis.

Duplex ultrasound is used to evaluate the entire length of both main renal arteries, as well as well arteries within the kidneys. Alterations in normal waveform shapes, velocities and ratios determine the presence or absence of stenosis.

Length of exam: 45 min – 60 min

Symptoms: High blood pressure, chronic renal failure, abnormal creatinine/BUN, etc.

Preparation: Do not eat, drink, or smoke for 8 hours prior to your exam.   If you are diabetic, please consult your doctor before fasting.

Mesenteric

A Mesenteric Evaluation examines blood flow in the arteries that carry oxygen rich blood to the stomach, intestines and other organs in the lower abdomen. A mesenteric artery stenosis (a narrowing or blockage of the mesenteric artery) can contribute to mesenteric ischemia, a potentially very serious condition. The condition is more common in smokers and in patients with high cholesterol.

Mesenteric ischemia may also be caused by a blood clot (embolus) that moves through the blood and suddenly blocks one of the mesenteric arteries. The clots usually come from the heart or the aorta. These clots are more commonly seen in patients with abnormal heart rhythms (arrhythmias), such as atrial fibrillation.

During the ultrasound scan the technologist will pass a transducer over your abdomen to evaluate the quality and direction of flow in the superior and inferior mesenteric arteries.
Other arteries routinely examined include the abdominal aorta, celiac, hepatic and splenic arteries.

Length of exam: 45 min – 60 min

Symptoms: Abdominal pain, chronic diarrhea, unexplained weight loss, fear of food (or pain associated with eating.

Preparation: Do not eat, drink, or smoke for 8 hours prior to your exam.   If you are diabetic, please consult your doctor before fasting.

Hepatoportal

The portal vein, hepatic veins, and the hepatic artery are the major blood vessels within the liver.   When pressure increases in the portal vein due to thrombus or external compression, flow within the portal vein decreases impairing liver function. This is called Portal Hypertension.   If the pressure is too great, alternative venous pathways (varices) may develop to bypass the narrowed area.   In some cases the liver resistance increases until it is greater than the portal vein blood pressure, causing a reversal of flow (hepatofugal flow) which can cause a back up of blood which can lead to splenomegaly (enlargement of the spleen).

A hepatoportal vascular examination uses state-of-the-art ultrasound equipment to analyze the blood vessels that feed and drain the liver.   The main portal vein will be evaluated for patency, direction of flow, size, and blood flow velocity.   The hepatic artery and hepatic veins will also be examined for patency during the exam.

Length of exam: 45 min – 60 min

Symptoms: Ascites, abdominal pain

Preparation: Do not eat, drink, or smoke for 8 hours prior to your exam.   If you are diabetic, please consult your doctor before fasting.

Abdoninal Aortic Aneurysms (AAA)

Abdominal aortic aneurysms (AAA) are considered the “silent killer” because most patients do not complain of any symptoms and the disease can easily go undetectable. A physician may detect the presence of an AAA by abdominal palpation or it can be discovered by an abdominal ultrasound. Ultrasonography provides an assessment of the size and extent of the aneurysm and is commonly used for surveillance.

Length of exam: 45 min – 60 min

Symptoms: Usually asymptomatic unless the aneurysm has ruptured.   The symptoms associated with a ruptured AAA may include sudden lower back, flank, abdominal, or groin pain, hypovolemic shock with hypotension, tachycardia, cyanosis, and altered mental status.

Preparation: Do not eat, drink, or smoke for 8 hours prior to your exam.   If you are diabetic, please consult your doctor before fasting.