How is a Stroke Diagnosed? A Comprehensive Guide to Brain Imaging and Other Tests
Learn what imaging technology is used to diagnose strokes
A stroke is a serious medical emergency that may cause permanent damage to the brain if not treated quickly. It is important to know how a stroke is diagnosed so that you can get the appropriate treatment as soon as possible.
Determining the Type of Stroke with Imaging
Once a physician has determined that a patient is experiencing stroke symptoms, this will need to be confirmed with imaging, such as a CT scan or MRI scan. Imaging will also provide answers to the question whether the stroke is ischemic or hemorrhagic. Knowing this is information is the vital next step to getting the right treatment and reducing the damaging effects of the stroke .
A computed tomography (CT) scan is typically the first type of imaging for acute stroke diagnosis.. A CT scan uses x-rays to create a 3D image of the brain which can show if there is bleeding. With a single view x-ray (for a broken bone, for example), typically there is only one or two views taken which creates a 2D image. In a CT scan, multiple x-ray pictures are taken from different angles to create a much more complete image. There are also CT scans where contrast dye is injected into the veins to be able to see the blood vessels in the brain and neck. This is called CT angiography. Another way of looking at the brain using a CT scan is called CT perfusion, where contrast dye helps the doctor to see which parts of the brain affected by a stroke still have blood supply. The benefits of a CT scan are that it is faster and more widely available than an MRI but at the cost of not being as detailed as an MRI. Another risk is that CT scans use radiation which can increase risk of cancer.
A magnetic resonance imaging (MRI) scan works by using the body's magnetic properties. By utilizing magnets and radio waves it produces a detailed 3D image of the brain. No radiation is used. Because it is so sensitive, it is ideal for determining the extent of brain damage caused by a stroke.. Additionally, it can also help determine if someone has suffered a stroke versus a transient ischemic attack (TIA). MRI is more sensitive than a CT scan and can pick up on smaller changes in the brain, but typically takes longer to administer. Because it uses magnets, some people may not be able to get an MRI if they have certain medical devices or injuries that have left metal in a person's body.
Other Imaging Tests for Determining Cause of Stroke
CT and MRI scans are the first tests obtained when someone has a stroke. In some cases, additional imaging tests may be necessary to determine the cause of a stroke. These tests are often utilized once a patient's stroke has been stabilized and treated.. They can be used to look at blood vessel health within the heart, brain, and entire body, including:
- Echocardiogram to look at the heart and blood vessels to see if there is a problem with the heart
- Carotid ultrasound to assess the health of the vessels that supply blood to the brain
- Venous doppler to look for any suspected clots in the arms or legs
With the results of these tests, the medical team will be able to treat the patient and help reduce risk factors for another stroke.
Moving Forward with Clarity
The right tests are essential for immediate treatment, long-term management, and preventing unnecessary complications. With a stroke, time is of the essence. Knowing what to expect at the hospital and which tests should be done as soon as possible can help you or your loved one get the best possible care.