Vascular Ultrasound Laboratory
The Swedish Vascular Ultrasound Laboratory performs specialized exams to assist in the diagnosis and treatment of vascular disease. In addition to conventional examinations for peripheral arterial occlusive disease, abdominal aortic aneurysms, deep vein thrombosis, chronic venous disease, renal and mesenteric disease and dialysis access, this center performs cutting-edge studies to detect abnormalities of the cerebral circulation. Services at the vascular ultrasound laboratory include:
- Peripheral Vascular and Visceral Vascular Ultrasound studies
- Neurovascular Ultrasound studies
Our physicians and sonographers have garnered broad recognition for their advanced expertise in non-invasively studying cerebrovascular disease using innovative test protocols. Ultrasound evaluations of the cerebral circulation are pain free, require no preparation and are cost-effective.
The Swedish Vascular Ultrasound lab is accredited in all five testing areas by the Intersocietal Accreditation Commission (IAC), and provides comprehensive diagnostic services aimed at reducing the incidence, morbidity and mortality of stroke and other vascular diseases.
- Transcranial Doppler (TCD) Ultrasound Imaging: This exam uses ultrasound to evaluate the blood flow inside the head by examining the basal cerebral arteries. For this test, an ultrasound transducer is placed over the temporal bone (in front of the ear), over the closed eyelid, and at the base of the skull in order to acquire signals. Arteries that can be examined include the middle, anterior and posterior cerebral, ophthalmic and carotid siphon and the vertebral and basilar arteries.
- Interoperative/Endovascular Blood Flow Monitoring: The purpose of this monitoring is to detect significant decreases or increases in blood flow, and/or any possible microemboli (clots) that could result in neurological complications. Information about blood flow is gathered in real time, which allows for corrective action to be taken during a procedure.
- Detect Vertebral Artery Compression: During this test, the posterior cerebral arteries are monitored during different head positions. When blood flow velocity significantly drops with head turning, and there is a secondary response when the head is turned back to a neutral position, the exam indicates that there is a mechanical compression of the vertebral arteries. This result may lead to further evaluation, with potential surgery to relieve the compressing mechanism.
- Cerebral Emboli Monitoring: The purpose of cerebral emboli monitoring is to track whether emboli (plaque or clots broken away from the heart) are present in the bloodstream. Very small micro emboli can be detected and counted using transcranial Doppler (TCD) technology by monitoring the intracranial arteries.
- Carotid & Vertebral Ultrasound to Detect Atherosclerosis: A carotid/vertebral duplex test uses high frequency ultrasound to visualize blood vessel walls and examine bloodflow within the carotid, vertebral and subclavian arteries. Information regarding the degree and location of atherosclerosis and other abnormalities is obtained noninvasively. The information gathered by this exam is used to guide treatment decisions. Treatments used in the management of carotid atherosclerosis include medical therapy, carotid endarterectomy (CEA) and/or carotid artery stenting (CAS).
- Bubble Study for Patent Foramen Ovale (PFO): A patent foramen ovale (PFO) is a defect in the wall between the two upper chambers of the heart. This defect is an incomplete closure of the atrial septum, that can allow blood to pass directly from the right atrium to the left atrium, bypassing the filtering system of the lungs. If blood clots are present, they can move unfiltered into the left atrium and then into the brain, causing a stroke. The Bubble Study, using transcranial doppler ultrasound, has proven to be a sensitive and specific method to diagnose the condition.
- Vasomotor Reactivity Exam (CO2 Challenge) to Detect Stroke/Ischemia Risk: When cerebral blood flow is reduced, the brain will try to compensate, dilating smaller arteries in an effort to maintain flow. This test measures the ability of the circulation to dilate and constrict in response to changes in carbon dioxide, which can act as a powerful vasodilator. Vasomotor reactivity (VMR) is defined as the percent change in blood flow velocity in response to changes in CO2, and helps identify individuals who are at risk for or have evidence of low flow ischemia.