Patients admitted for stroke treatment through the emergency department are immediately examined and assessed on a scale that helps doctors measure the severity of symptoms. Before doctors give treatment, they must determine that the patient is having a stroke and if the stroke is caused by a blood clot (ischemic) or ruptured blood vessel (hemorrhagic). The medications given for the two types of stroke work in opposite ways, so doctors must know the type of stroke before treatment can begin.

The Sutter Stroke Center offers advanced diagnostic equipment, providing doctors with the widest possible selection of tools. A full range of tests are available at the Stroke Center 24 hours, every day. In addition, all Stroke Center doctors have remote access from their homes to receive test results and to view scans and images. Sutter’s teleradiology system makes it easy for doctors from multiple specialties to collaborate on a patient’s case while eliminating drive time and speeding the start of treatment.

Once testing has provided adequate insight into the patient’s condition, doctors move quickly to begin the appropriate treatment. The following are the most common tests used to diagnose the cause, exact location and severity of a stroke:

Computed Tomography (CT) Scanning: Doctors typically begin with a cerebral computed tomography (CT) scan because it is fast and allows them to rule out hemorrhaging in the brain. The Stroke Center’s CT scanning capabilities also include CT angiography, which uses contrast dye injected into a blood vessel to make artery structure more visible during a CT scan. CT angiography (CTA) is similar to a head and neck angiogram except that it uses computed tomography rather than standard X-ray technology. The Stroke Center also provides CT perfusion (CTP), which is often done in conjunction with a CTA scan, using the same contrast dye to allow doctors to measure blood flow in the brain. By combining all three technologies during the acute phase of a stroke, Sutter Stroke Center doctors gain a clear idea of the type of stroke, its location, and the extent of brain tissue affected. With that understanding, doctors are able to determine the most effective course of treatment for each patient. All CT scanning techniques are available 24 hours a day, seven days a week.

Magnetic Resonance Imaging (MRI): Doctors may elect to perform a test called magnetic resonance image (MRI) of the head to get a more detailed view of soft tissue structures such as blood vessels and brain tissue. MRI uses a magnetic field and radio waves to create pictures of internal body structures. Because of the magnetic field, however, MRIs cannot be performed on patients with pacemakers or other implants that contain metal. In addition to standard MRI scanning of the head, Sutter Stroke Center provides around-the-clock availability for MRI techniques that include diffusion-weighted MRI, magnetic resonance angiogram (MRA), and MR venography. Diffusion-weighted MRI (DWI) is a highly sensitive test that shows even minute amounts of swelling in affected areas of the brain, which begins occurring shortly after a stroke occurs. MRA details the structure of blood vessels in the brain. MR venography (MRV) detects blood flow through the veins taking oxygen-depleted blood out of the brain and back to the heart. An MRV is used to detect a reduced flow of blood in the veins and may be used to help determine the severity of an ischemic or hemorrhagic stroke or to detect a blood clot in the veins of the brain. Though the vast majority of strokes involve the arteries, blood clots in the veins (cerebral venous thrombosis) are becoming more widely recognized with the more sensitive imaging technology available today.

Cerebral Angiography: An angiogram of the head and neck uses digital X-ray technology with contrast dyes injected into a patient’s artery to provide doctors with a view of the arteries. Conditions typically looked for using cerebral angiograms include narrowing of the artery due to plaque buildup, bulging of the artery caused by an aneurysm, unusual patterns of blood vessels caused by a tumor or arterial venous malformation, or an artery moved from its normal location due to pressure from a tumor. Cerebral angiography is available at Sutter Stroke Center around the clock, seven days a week.

Extracranial Ultrasonography: Passing an instrument that looks like a wand over the skin, technicians send sound waves into blood vessels that reflect back to equipment that converts them to images. From the images, doctors can see the structure of arteries leading to the brain. The test provides good accuracy and a safe alternative to patients who cannot tolerate contrast dyes or who have pacemakers or other metal-containing implants that are not compatible with the magnetic field used in MRI technology. Ultrasound testing is available at Sutter Stroke Center around the clock, seven days a week.

Transcranial Doppler: A highly sensitive ultrasound technology allows doctors to get a better view of blood flow through the arteries within the brain. The test is especially helpful when patients cannot tolerate contrast dyes or have pacemakers or other metal-containing implants that are not compatible with the magnetic field used in MRI technology. Transcranial Doppler is available at Sutter Stroke Center on an as-needed basis.

Transthoracic and Transesophageal Echocardiography ( Grade IA) : Because many strokes are related to the heart and the arteries leading from it, doctors often include cardiac imaging as part of diagnosis. Transthoracic echocardiography (TTE) checks the heart for clots, heart-valve conditions, and function of the left ventricle. Transesophageal echocardiography (TEE) is used to detect heart and aorta conditions that may cause strokes, including aneurysms, clots, valve conditions and other issues. Both tests are available around the clock, seven days a week at Sutter Stroke Center and all tests are performed and interpreted by specially trained technicians and cardiologists.

Nuclear Imaging: In some cases, doctors may decide additional testing is necessary to determine the cause of a stroke. Highly sensitive imaging using positron emission tomography (PET) or single-photon emission computed tomography (SPECT) cameras is available away from Sutter Stroke Center on a non-emergency basis. PET imaging is available nearby and SPECT imaging is available at Sutter Roseville Medical Center.

Clinical Laboratory Testing: Tests of blood and urine often help doctors determine body chemistry and how different organs of the body are functioning. Sutter Stroke Center provides laboratory testing with fast turnaround on results 24 hours a day, seven days a week.

The doctors treating you or a loved one are available to answer any questions you have about why tests are being performed and what is involved. If you would like more information, please see strokein our health information section.You can find additional information by calling the American Stroke Association at 1-888-4STROKE or by visiting their Web site at www.strokeassociation.org. If you or someone you know has had a stroke, you can also call the American Stroke Association “Warmline” at 1-800-553-6321. In addition, the National Institute of Health’s National Institute of Neurological Disorders and Stroke offers booklets and additional information. You can also find useful information on the National Stroke Association Web site.