An extracranial duplex exam uses risk-free, painless non-invasive ultrasound to examine the vessels responsible for 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 and then on up to the brain. The technologist will pass a transducer (probe or wand) over your neck to look at your subclavian, vertebral, internal and external carotid arteries to detect and measure narrowing. Narrowing is usually caused by a build-up of cholesterol or fatty material referred to as atherosclerosis. When present, atherosclerosis can increase an individual’s risk for stroke. Learn more here.
Indications
- To assess for risk of stroke or TIA (transient ischemic attack)
- To noninvasively screen for carotid artery disease and atherosclerosis (in the presence of risk factors: high blood pressure, diabetes, tobacco use, increased lipid markers, etc.)
- To diagnose the cause of known neurologic events like TIA or stroke
- Monitoring (surveillance) of known carotid artery stenosis
Patient Preparation
Try to avoid wearing high collar tops like turtleneck garments to the exam.
