Why Stroke Diagnosis Starts with Brain Imaging
When someone shows signs of a stroke, the first step is to quickly confirm the diagnosis. Doctors usually begin with a CT scan or MRI of the brain. These imaging tests use X-rays or magnetic fields to create detailed pictures of the brain. A CT scan is often the first choice because it’s fast and can quickly show if there’s bleeding or a blockage. An MRI gives even more detail, especially for small or deep brain injuries.
Advanced Imaging: Finding the Exact Problem
After the initial scan, more specialized tests may be needed. CT angiography (CTA) and MR angiography (MRA) use contrast dye to highlight blood vessels in the brain. These tests help doctors see exactly where a blockage or abnormality is located. Sometimes, a perfusion scan is used to check how much brain tissue is still healthy and can be saved. This information is crucial for deciding the best treatment.
Checking Blood Flow: Ultrasound and Angiography
Doctors also use ultrasound to check blood flow in the neck and brain. Carotid ultrasound uses sound waves to look at the arteries in the neck and see if there’s plaque buildup. Doppler ultrasound can show the speed and direction of blood flow. In some cases, a cerebral angiogram is done. This involves inserting a thin tube into a blood vessel and injecting dye to get a detailed picture of the brain’s blood vessels.
Heart Tests: Why ECG and Echocardiogram Matter
Not all strokes are caused by problems in the brain. Sometimes, the heart is the source. An electrocardiogram (ECG) checks the heart’s electrical activity and can reveal irregular rhythms that might have led to a stroke. An echocardiogram uses sound waves to create images of the heart. This test is especially important for finding a patent foramen ovale (PFO), a small hole between the upper chambers of the heart.
What Is Patent Foramen Ovale?
A patent foramen ovale is a common heart defect that’s present in about 25% of adults. It’s a small opening between the left and right atria that usually closes after birth but sometimes stays open. Most people with a PFO have no symptoms, but in some cases, it can allow blood clots to pass from the right side of the heart to the left, increasing the risk of stroke.
How Is PFO Diagnosed?
Diagnosing a PFO usually involves an echocardiogram. A special type called transesophageal echocardiography (TEE) is often used because it gives a clearer view of the heart’s upper chambers. During the test, a small probe is passed down the throat to get detailed images. Sometimes, a bubble study is done, where a saline solution is injected to see if bubbles pass through the hole.
Why Finding PFO Matters After a Stroke
Discovering a PFO after a stroke is important because it can change the treatment plan. For some patients, closing the hole with a device or surgery may reduce the risk of another stroke. It’s especially relevant for younger patients who don’t have other obvious risk factors for stroke.
Other Tests That Help Complete the Picture
Blood tests are also part of the diagnosis. They can check for conditions like high cholesterol or diabetes that might contribute to stroke risk. In some cases, additional tests like a cerebral blood flow test or digital subtraction angiography may be needed to get a full understanding of the situation.
Putting It All Together
Diagnosing a stroke and finding a patent foramen ovale involves a combination of brain imaging, blood flow tests, and heart tests. Each step helps doctors understand the cause and choose the best treatment. For patients, knowing about these tests can make the process less stressful and help them take an active role in their care.