Other Ways to Determine If a Stroke Has Occurred
Other Stroke Tests
Healthcare providers may recommend other tests for stroke. These tests can either be used for stroke screening, to help diagnose a stroke, and/or to find the stroke cause. Some of these stroke tests include:
- Carotid Doppler ultrasound
- Carotid arteriography
- Cerebral angiography (also known as a cerebral angiogram, cerebral arteriogram, or digital subtraction angiography)
- Magnetic resonance angiogram (MRA) or functional magnetic resonance imaging (fMRI)
- Transcranial Doppler
- Electrocardiogram (EKG) -- to look at the heart's electrical activity along with any signs of a heart attack
- Lumbar puncture
- Electroencephalography (EEG).
Carotid Doppler Ultrasound
Carotid Doppler ultrasound (carotid Doppler) is a painless, noninvasive test in which sound waves above the range of human hearing are sent into the neck. Echoes bounce off the moving blood and the tissue in the artery and can be formed into an image. An ultrasound is fast, painless, risk-free, and relatively inexpensive compared to MRA and arteriography; however, it is not considered to be as accurate as arteriography.
Doctors may recommend a duplex Doppler ultrasound to decide if an individual would benefit from a surgical procedure called carotid endarterectomy. This surgery is used to remove fatty deposits from the carotid arteries and can help prevent stroke.
Arteriography is an x-ray of the carotid artery taken when a special dye is injected into the artery. This procedure carries its own small risk of causing a stroke and is costly to perform. The benefits of arteriography over MRI and Doppler ultrasound are that it is extremely reliable and still the best way to measure narrowing of the carotid arteries. Healthcare providers may use an arteriography to decide if an individual would benefit from a carotid endarterectomy.
Healthcare providers may use a cerebral angiography to image the blood vessels of the brain and the blood flowing through them. This allows a healthcare provider to see problems in the brain's blood vessels, such as narrowing or a blockage. Doctors may recommend a cerebral angiography after a CT scan; it is often useful for determining if a stroke has occurred and its location.
Angiography involves entering a catheter into the body to inject a dye (a contrast medium) into the carotid arteries, the vessels of the neck that lead to the brain. Then regular x-ray is used to image the dye that is flowing through the blood vessels.
Magnetic Resonance Angiogram (MRA) or Functional Magnetic Resonance Imaging (fMRI)
Besides a regular MRI, two other types of MRI scans include magnetic resonance angiography (MRA) and functional magnetic resonance imaging (fMRI). Doctors use these MRI scans to diagnose cerebrovascular disease and to predict the risk of stroke. MRA is used to detect stenosis (a blockage of the brain arteries) inside the skull by mapping flowing blood. Functional MRI uses a magnet to pick up signals from oxygenated blood and can show brain activity through increases in local blood flow.