Stroke

Diagnosis

Mayo Clinic specialists may use a variety of screening tools to determine stroke risk or accurately diagnose stroke.

Physical Examination

Mayo physicians will listen to the heart, look into the eyes and do a general exam to evaluate the patient for other signs of vascular disease. A stethoscope may be used to listen for a bruit (an abnormal sound produced by turbulence in one of the two main arteries that supply blood to the head). A bruit often indicates atherosclerosis (fatty deposits that block the flow of blood through the arteries).

Basic Laboratory Tests

In addition to checking blood pressure and cholesterol levels, doctors at Mayo Clinic may test patients for diabetes and check the blood for an elevated level of the amino acid homocysteine. A high level of homocysteine may be associated with an increased risk of cardiovascular disease and is a risk factor for stroke. Homocysteine levels may be modified with certain treatments.

Computed Tomography (CT)

At Mayo, CT scans are generally the first diagnostic test completed when a patient with suspected stroke arrives in the emergency room. CT scans are used to distinguish between ischemic and hemorrhagic stroke. The test involves low-dose X-rays and allows physicians to visualize the brain.

Computed Tomography Angiography (CTA)

In CTA, dye is injected into the blood vessels. X-ray beams then create a three-dimensional image of blood vessels in the neck and brain. CTA is used to identify aneurysms, arteriovenous malformation and arterial narrowing.

Magnetic Resonance Imaging (MRI)

MRI uses a strong magnetic field to generate a three-dimensional view of the brain. MRI is used to detect an area of brain tissue damaged by ischemic stroke. It provides a high level of anatomic detail to help physicians locate the stroke site precisely and determine the extent of damage.

MRI procedures are performed in a special room free of metallic equipment for safety. New technologies developed for the early detection of stroke, including diffusion and perfusion-weighted MRI, are also available at Mayo Clinic.

Magnetic Resonance Angiography (MRA)

MRA is a noninvasive technology that images the cerebral (head) arteries and veins. It also yields valuable information regarding other arteries supplying the brain. This procedure uses a strong magnetic field similar to MRI. Mayo Clinic researchers are at the forefront of research that has optimized the clarity of MRA images.

Carotid Ultrasonography

In this ultrasound of the neck, sound waves pass through tissue and then return, creating on-screen images that show any narrowing or clotting in the carotid (neck) arteries and how fast blood is flowing through them to the brain.

Transcranial Doppler (TCD)

TCD is an ultrasound procedure that shows blood flow through the cerebral vessels via a small probe placed against the skull. TCD is a portable test that can be performed at a patient's bedside to follow the progress of medical treatment for stroke.

Positron Emission Tomography (PET)

PET scans measure brain cell metabolism to show whether the brain tissue is functioning, even though blood flow to that area appears diminished.

Arteriography

Arteriography produces a detailed view of arteries in the brain not normally seen in X-rays. A catheter is inserted in an artery in the arm or leg and dye is injected into the blood vessels leading to the brain. X-ray images show any abnormalities of the blood vessels, including narrowing, blockage or malformations such as aneurysms or arteriovenous malformations.

Echocardiogram (ECG)

ECG is an ultrasound of the heart. It is conducted to determine whether an underlying heart problem is contributing to the risk of stroke. In ECG, a transducer (wand-like device) collects echoes (reflected sound waves) from the heart and transmits them to a machine. The ultrasound probe may be placed on the chest or a small tube may be inserted down the throat.

Related Information

Knowing the risk factors and living healthfully are the best steps to take to prevent a stroke.