What diagnostic studies should be ordered for a stroke workup?

From the Guidelines

A comprehensive stroke workup should include both immediate and follow-up diagnostic studies, with a non-contrast head CT scan and CT angiography (CTA) of the head and neck being the initial imaging studies of choice, as recommended by the most recent guidelines 1. The initial imaging studies are crucial in defining the extent of infarct and evaluating for hemorrhage, and guiding the next steps in interventional workup.

• The non-contrast head CT scan should be ordered to rule out hemorrhagic stroke and establish a baseline.
• CT angiography (CTA) of the head and neck should be performed to evaluate for large vessel occlusions or stenosis. Additional diagnostic studies that should be considered include:
• MRI with diffusion-weighted imaging, which is superior for detecting acute ischemic changes and should be performed within 24-48 hours when possible.
• Laboratory tests, such as complete blood count, comprehensive metabolic panel, coagulation studies (PT/INR, PTT), lipid panel, hemoglobin A1C, and cardiac biomarkers.
• An electrocardiogram (ECG) to detect arrhythmias, particularly atrial fibrillation, as recommended by the American Heart Association/American Stroke Association 1.
• Continuous cardiac monitoring for at least 24 hours to detect paroxysmal arrhythmias.
• Echocardiography (preferably transesophageal) to evaluate for cardiac sources of emboli, such as thrombi, patent foramen ovale, or valvular disease, especially in patients with cryptogenic stroke 1. These diagnostic studies help determine stroke etiology, which guides secondary prevention strategies and reduces recurrence risk. For younger patients or those without obvious stroke etiology, additional tests may include hypercoagulability studies, inflammatory markers, drug screens, and tests for vasculitis, as suggested by the American Heart Association/American Stroke Association guidelines 1.

From the Research

Diagnostic Studies for Stroke Workup

The following diagnostic studies are commonly ordered for a stroke workup:

• Non-contrast computed tomography (CT) scan to exclude hemorrhage and identify early signs of ischemia 2, 3, 4
• CT angiography (CTA) to identify intracranial large vessel occlusions and cervical carotid or vertebral artery disease 3, 4
• CT perfusion to evaluate tissue viability and identify areas of ischemia 3, 4
• Magnetic resonance imaging (MRI) to provide valuable insights for outcomes prognostication and stroke etiology 3, 5, 6
• Magnetic resonance angiography (MRA) to evaluate blood vessels and identify areas of occlusion or stenosis 3

Imaging Modalities

Different imaging modalities have their own advantages and disadvantages:

• Non-contrast CT is widely available and rapid, but may not show early signs of ischemia 2, 3, 4
• MRI is more sensitive than CT for detecting acute and chronic intracerebral hemorrhage, but may be less available and take longer to perform 5, 6
• CT perfusion and CTA are useful for evaluating tissue viability and identifying areas of ischemia, but may require additional equipment and expertise 3, 4

Clinical Scenarios

The choice of diagnostic study may depend on the clinical scenario:

• In patients with acute stroke symptoms, non-contrast CT is often the first line of imaging to exclude hemorrhage and identify early signs of ischemia 2, 3, 4
• In patients with suspected large vessel occlusion, CTA and CT perfusion may be useful for evaluating tissue viability and identifying areas of ischemia 3, 4
• In patients with chronic stroke symptoms, MRI and MRA may be useful for providing valuable insights for outcomes prognostication and stroke etiology 3, 5, 6