Acute Stroke Diagnostic Approach

Immediate Diagnostic Imaging

The American College of Radiology recommends noncontrast CT or MRI must be performed immediately to exclude intracranial hemorrhage and assess extent of ischemic changes 1, 2
CT is typically faster and more widely available for initial assessment, while MRI with diffusion-weighted imaging (DWI), FLAIR, and gradient-recalled echo (GRE) or susceptibility-weighted imaging (SWI) is preferred when available 24/7 and can be completed rapidly 1
The American College of Radiology suggests that concordant results from at least two noninvasive imaging techniques can determine treatment eligibility for revascularization procedures 1

Essential blood work includes complete blood count (CBC), electrolytes and glucose, coagulation studies (INR and aPTT), renal function (creatinine and eGFR), and troponin, as recommended by the International Journal of Stroke 3, 2
These tests should not delay imaging or treatment decisions but are necessary for determining eligibility for thrombolytic therapy 3

The International Journal of Stroke recommends that a 12-lead ECG should be completed to identify atrial fibrillation, acute coronary syndrome, or other cardiac abnormalities 3, 2
ECG monitoring for >24 hours is recommended for patients with suspected embolic stroke to detect paroxysmal atrial fibrillation, as suggested by the Journal of the American College of Radiology and Stroke 1, 4
Echocardiography should be performed for patients with suspected cardiac source of embolism, including evaluation for intracardiac thrombus, valvular disease, patent foramen ovale, and other structural abnormalities 1, 4

Stroke severity must be assessed using a validated scale such as the National Institutes of Health Stroke Scale (NIHSS) or Canadian Neurological Scale (CNS), as recommended by the International Journal of Stroke and Praxis Medical Insights 3, 2
Time of symptom onset (last known well) is crucial for determining treatment eligibility 2

Swallowing screening using a validated tool should be completed within 24 hours by a trained practitioner, as recommended by the International Journal of Stroke and Praxis Medical Insights 3, 2
Chest X-ray is indicated when evidence of acute heart disease or pulmonary disease exists, but can be deferred until after acute treatment decisions unless patient is hemodynamically unstable 3

For patients within the treatment window (0-4.5 hours for IV tPA), prioritize noncontrast CT or MRI to exclude hemorrhage, and consider concurrent CTA if endovascular therapy is being considered, as recommended by the Journal of the American College of Radiology and Praxis Medical Insights 1, 2
For patients beyond the acute treatment window (>4.5 hours), emphasis shifts to secondary prevention workup, including vascular imaging (CTA, MRA, or duplex ultrasound) to assess carotid arteries, echocardiography to assess for cardiac sources, and extended cardiac monitoring to detect paroxysmal atrial fibrillation 1, 4

Ensure completion of routine investigations, including brain imaging, noninvasive vascular imaging, 12-lead ECG, extended cardiac monitoring (>24 hours), echocardiography, and routine blood tests, as recommended by Stroke 4
Consider investigations for rarer causes, including vasculitis, hypercoagulable states, and arterial dissection, based on clinical suspicion 4