Diagnosis of Acute Ischemic Stroke

Susan Liu Hoki Gillian Lieberman, MD

July 2002

Role of Imaging in the Diagnosis and Mangagement of Acute Cerebral Infarction Susan Liu Hoki, Harvard Medical School Year III Gillian Lieberman, MD

Susan Liu Hoki Gillian Lieberman, MD

Goals • Understand how imaging studies help in stroke diagnosis and management through examining findings in patients at different stages of acute ischemic stroke • Know the advantages of different tests in stroke imaging

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Susan Liu Hoki Gillian Lieberman, MD

Background: Stroke • Stroke is a lay term meaning a condition due to vascular lesions of the brain caused by hemorrahage, embolism, thrombosis, or rupturing aneurysm • Primarily diagnosed clinically and confirmed and followed through imaging tests 3

Susan Liu Hoki Gillian Lieberman, MD

Background: Stroke Types Most common stroke etiologies: 1) Cerebral Infarction 80% 2) Primary Intracranial Hemorrhage 15% 3) Nontraumatic subarachnoid hemorrhage 5% * FOCUS: Acute Cerebral Infarction

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Susan Liu Hoki Gillian Lieberman, MD

Menu of Radiological Tests • Cerebral Angiogram • CT: w/ or w/o contrast CT angiogram (CTA) • MR: w/ or w/o contrast T1 or T2 weighted (T1WI, T2WI) FLAIR Diffusion weighted image (DWI) Susceptibility MR angiogram 5

Susan Liu Hoki Gillian Lieberman, MD

Cerebral Angiogram • Gold standard in the past • Outdated and replaced by MRI/MRA • High risk of producing further thrombus formation in brain and causing renal failure

Courtesy of Dr. Steve Reddy, BIDMC

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Susan Liu Hoki Gillian Lieberman, MD

Patient 1: CT w/o Contrast Test of Choice in Emergencies 1) Distinguish between ischemic and hemorrhagic stroke 2) Normal CT in patient with