Cerebrovascular Evaluation
A cerebrovascular evaluation uses non-invasive 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 and head. The test includes examination of the subclavian, vertebral, internal and external carotid arteries as well as intracranial circulation. This non-invasive 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.
A transient ischemic attack (TIA) is a “mini-stroke” that results in stroke-like symptoms which disappear with no lasting damage. About 15% of strokes are preceded by a TIA, so it is very important to know them symptoms that may lead to stroke and to contact your doctor immediately or call 9-1-1
Common symptoms, or stroke warning signs, may include one or more of the following:
- Sudden numbness, weakness, or inability to move (paralysis) of face, arm or leg especially on one side of the body
- Sudden trouble seeing in one or both eyes (such as dimness, blurring, double vision, or loss of vision)
- Sudden confusion, trouble speaking or understanding
- Sudden trouble walking, dizziness, loss of balance or coordination
- Sudden severe headache with no known cause
A cerebrovascular evaluation is often ordered if you have had any stroke warning signs (TIA) or have suffered a stroke.
Patient Preparation: None
Lower/Upper Extremity Venous Evaluation
If you have been referred for a venous evaluation, non-invasive ultrasound will be used to evaluate blood flow in your legs or arms or both. Veins return deoxygenated blood to the heart. There are two main sets of veins in the legs: deep veins which lie well within the tissue, and superficial veins which are closer to the surface. Deep Vein Thrombosis (DVT) refers to the development of a blood clot in the deep veins, which can cause partial or total blockage of blood flow in these vessels. Pain, swelling or redness in the limb may result. Unlike ‘superficial thrombophlebitis’ (a blood clot in the superficial veins), DVT is of more serious concern since there exists the possibility that it might break off and travel to the lungs. This is called pulmonary embolism. The risk of pulmonary embolism is reduced by prompt recognition and treatment of DVT.
During a venous evaluation the technologist will pass a transducer (probe) over your limb(s) to examine blood flow within the veins. Common symptoms indicating the need for a venous evaluation may include one or more of the following:
- Pain, swelling or tenderness in the limb
- Ulcers or sores, particularly in the ankle region, that have difficulty healing
- A bluish discoloration of the skin
- An abnormal flush or redness of the skin
- Suspected pulmonary embolus
Patient Preparation: None
Lower/Upper Extremity Arterial Evaluation
Peripheral arteries are the blood vessels that provide oxygenated blood to the legs and arms. Healthy peripheral arteries are smooth and unobstructed, allowing adequate blood flow to the extremities both at rest and during walking or exercise.
The most common cause of Peripheral Arterial Disease (PAD) is atherosclerosis, where cholesterol and fatty substance build up in the walls of the arteries forming what is referred to as “plaque”. Eventually, plaque can result in loss of flexibility and narrowing of the artery, reducing or completely obstructing the flow of blood.
If you have been referred for a Lower or Upper Extremity Arterial evaluation, ultrasound will be used to assess blood flow through the arteries of your legs or arms. An arterial evaluation begins with blood pressure measurements in the arms and the ankles. Based on a calculation of the two measurements, the technologist may begin the ultrasound scan or may have you walk on a treadmill.
During an ultrasound scan the technologist will pass a transducer (probe) over your limbs to evaluate blood flow of the arteries. The exam may also include evaluation of arteries in your trunk and pelvic region (abdominal aorta and iliac arteries) as they supply blood to the legs. This exam is also helpful in diagnosing aneurysms (a bulging of the wall of a blood vessel).
Common symptoms indicating the need for an arterial evaluation may include one or more of the following:
- Pain, abnormal coloring, or lack of pulses in any portion of the extremities
- Pain or cramping in the calf, thigh or buttock that is alleviated with rest
- A severe ache in the toes, forefoot or heel which is relieved by inducing blood flow with gravity (for example, dangling the foot over the bed)
- Ulcers or sores that have difficulty healing
- Gangrene
Patient Preparation: There is no food or drink (except water with medications) 8 hours prior to the test. Diabetic can eat and medicate as usual.
Renal Evaluation
A renal vascular evaluation examines blood flow in the kidneys and renal arteries (arteries that supply blood to the kidneys). Renal artery stenosis (a narrowing or blockage of the renal artery) can contribute to hypertension (high blood pressure) and may be a major factor in the development of renal failure.
During a renal vascular evaluation, the technologist will pass a transducer (probe) over your abdomen and side to evaluate the blood flow in the kidneys and renal arteries.
Common symptoms indicating the need for a renal evaluation may include one or more of the following:
- Hypertension (new onset or uncontrollable)
- Renal Failure
Patient Preparation: There is no food or drink (except water with medications) 8 hours prior to the test. Diabetic can eat and medicate as usual.
Abdominal Aortic Aneurysm (AAA)
The aorta is the largest artery in your body which passes from the heart to the rest of the body. An abdominal aortic aneurysm (AAA) is an enlargement of the aorta in the abdomen caused by arterial wall weakness resulting in dilation to an abnormal size.
An AAA can develop gradually or suddenly. Most abdominal aortic aneurysms develop over time from an accumulation of fatty deposits or other disease processes, which can cause a weakening in the vessel wall. A sudden occurrence may be due to a blunt trauma to the vessel, or a hereditary predisposition. An AAA Evaluation can determine if an aneurysm is present and provide measurements of the aorta to determine the precise location and size of the enlarged area.
Patients with an AAA may have this exam several times to determine if, and how fast, the AAA is expanding over time. During this exam the technologist will pass the ultrasound transducer (probe) over your abdomen and evaluate the abdominal aorta and any pertinent branching vessels. Remarkably, most people who have an AAA do not experience any symptoms. The presence of an AAA is often discovered incidentally during an X-ray or during an ultrasound evaluation ordered for another medical reason. Symptoms which can occur are often vague and may include one or more of the following:
- Pain in the chest, abdomen, or lower back, possibly spreading to the groin, buttocks, or legs The pain may be described as aching, gnawing, and/or throbbing, and may last for hours or days
- Pulsating or mass/lump in the abdomen.
- If the AAA ruptures, then you may suddenly feel weakness, dizziness, or pain, and you may eventually lose consciousness. This is a life-threatening situation and you should call 9-1-1 immediately for medical attention.
Risk factors for AAA include history of smoking, family history of AAA, and hypertension (high blood pressure).
Patient Preparation: There is no food or drink (except water with medications) 8 hours prior to the test. Diabetic can eat and medicate as usual.
Mesenteric Evaluation
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. During the ultrasound scan the technologist will pass a transducer (probe) 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.
Common symptoms indicating the need for a mesenteric evaluation may include one or more of the following:
- Abdominal pain
- Chronic diarrhea
- Unexplained weight loss
- Fear of food (or pain associated with eating)
Patient Preparation: There is no food or drink (except water with medications) 8 hours prior to the test. Diabetic can eat and medicate as usual.
Hepato-Portal Evaluation
A Hepato-Portal Evaluation examines blood flow in the arteries carrying oxygen rich blood to and from the liver. The test is used to assess the quality and direction of blood flow to assist in diagnosis of portal hypertension, and identify possible portal vein and/or hepatic vein thrombosis (blood clots). During the examination, the technologist will pass a transducer (probe) over your side and abdomen to examine the blood flow in the vessels in and around the liver and spleen. Other arteries routinely examined include the abdominal aorta and the splenic arteries.
Common symptoms indicating the need for this exam may include one or more of the following:
- Esophageal bleeding (along the esophagus)
- Abdominal pain
- Abdominal distention (protruding abdomen)
- Ascites (accumulation of fluid causing abdominal swelling)
- Hepatic encephalopathy – a condition in which the brain is impaired by the presence of toxic substances that are normally removed or detoxified by the liver.
Patient Preparation: There is no food or drink (except water with medications) 8 hours prior to the test. Diabetic can eat and medicate as usual.
Thoracic Outlet Evaluation
Thoracic Outlet Syndrome is due to the compression of the neurovascular structures (nerves and blood vessels) passing through the thoracic outlet. The thoracic outlet is a small space through which the main blood vessels and nerves to the arm must pass. This space is located near the base of the neck by the clavicle (collar bone). Its borders are defined by the scalene muscles in the neck that attach to the first rib and the clavicle, which lies directly above the first rib.
During a TOS Evaluation the technologist will place an ultrasound transducer (probe) at various places along the arm and evaluate the quality of blood flow. The patient will be asked to move his/her arms in various positions to determine if a significant change in blood flow occurs and/or can be elicited by certain maneuvers. The patient’s symptoms are also recorded during each portion of the exam.
Symptoms associated with Thoracic Outlet Syndrome include one or more of the following:
- Pain, numbness, tingling, weakness in the arm, hand, or fingers with specific motions/maneuvers (such a lifting arms overhead, pushing, pulling, etc.)
- Temperature changes, discoloration, or swelling of the hand or fingers
- Inability to grasp or hold onto objects
- Associated headaches and/or neck pain
Patient Preparation: None
Raynaud’s Evaluation
Raynaud’s phenomenon describes a condition characterized by intermittent attacks of ischemia (inadequate blood supply) to the skin. A Raynaud’s “attack” or episode usually occurs during exposure to cold temperatures and primarily affects the fingers and/or toes. Blood vessels near the skin surface normally become smaller (vasoconstrict) when exposed to cold temperatures in order to conserve and reduce energy heat loss.
Along the same lines, they will increase in size (vasodilate) when exposed to warm or hot temperatures. In a person with Raynaud’s phenomenon, however, these blood vessels will close entirely under cold temperatures and then be slower to dilate once the temperature increases.
While exposure to cold temperatures is the most common trigger to a Raynaud’s episode, emotional stress or certain medications can also cause an attack. During a Raynaud’s Evaluation, the technologist will take your blood pressure at several different levels along the affected limb(s). Next, they will pass an ultrasound transducer (probe) over several places along the limb(s) to evaluate the quality of blood flow. Infrared sensors will be placed on the fingers/toes of interest to further evaluate the blood flow at the skin surface. This technique will be performed with the hands/feet at room temperature and then again while submerged in ice water to observe the response to cold temperature exposure. Blood pressures at the fingers/toes will also be taken during the cold exposure.
Symptoms associated with Raynaud’s phenomenon include:
- Numbness or cold feeling in fingers and/or toes followed by discoloration (usually white) when exposed to cold temperatures or stress
- Pain upon re-warming of fingers/toes, usually accompanied by fingers/toes becoming blue or red
- Symptoms usually last a few minutes, but can last up to several hours
Patient Preparation: None
Dialysis Access Evaluation
Patients who need dialysis commonly have a graft placed or fistula created in either the arm or leg that provides access for kidney dialysis. During the evaluation the technologist will pass an ultrasound transducer (probe) along the limb in which the graft or fistula is located in order to evaluate the quality of the blood flow.
Common reasons this examination may be ordered are:
- Difficulty with needle placement
- Increased dialysis time
- Pain, swelling, or discoloration of the limb or digits (fingers/toes)
- Loss of pulse in the graft
- Palpable mass in the graft or limb
- Abnormal lab values
- Increased venous pressure during dialysis
Patient Preparation: None
For information about an exam not listed here please visit our section entitled “Exams for Clinicians”
