Stroke Diagnosis at BIDMC
Time is of the essence when patients are admitted to the Emergency Room with a suspected stroke. Certain treatments must be given within a few hours, from the start of the first symptom, in order to be effective. Our acute stroke team works together quickly to assess and immediately transport the patient for a CT scan as rapidly as possible.
A computed tomography (CT) scan uses radiation to create detailed images of the brain. This scan helps doctors determine the type of stroke (ischemic vs. hemorrhagic), its location and the extent of brain tissue injury.
Doctors may also order an MRI brain scan. Magnetic resonance imaging, with its large magnetic field, produces a sharper, more detailed image than a CT scan. Using techniques developed here at BIDMC, doctors review the MRI scan to help diagnose small, deep injuries within brain tissue.
There are other imaging tests that help diagnose and assess stroke:
- CTA: A computed tomographic angiography test, which requires an injection of special contrast dye, provides images of blood vessels supplying the brain. Doctors rely on this scan to look for abnormalities such as aneurysms (a blood-filled bulge in the vessel wall).
- MRA: A magnetic resonance angiography test maps blood vessels in the brain. This test can also help doctors pinpoint a cerebral aneurysm (a blood-filled bulge in the vessel wall in the brain).
- Perfusion MRI or CT: These tests map blood flow in the brain, and can help doctors detect brain areas with reduced blood flow.
Besides imaging scans, doctors may order ultrasound blood flow tests to check the condition of the neck and head arteries that supply blood to the brain, or an EEG (electroencephalogram) to assess the brain’s electrical activity.