Immediate Brain Imaging for Stroke Diagnosis

Introduction to Stroke Diagnosis

• The American Heart Association guidelines state that brain imaging is essential before treatment decisions can be made for stroke patients, as clinical features alone cannot reliably distinguish ischemic stroke from hemorrhagic stroke 1, 2, 4

Optimal Imaging Protocol

• A non-contrast CT scan of the brain should be performed immediately upon presentation and ideally be completed within 25 minutes of emergency department arrival and interpreted within 45 minutes 1, 2
• If no hemorrhage is visible on the CT scan, the patient may be a candidate for fibrinolytic therapy (rtPA) if within the appropriate time window and meets other eligibility criteria 1, 2

Critical Concurrent Evaluations

• While imaging is being obtained, essential laboratory tests such as blood glucose, complete blood count with platelet count, PT/INR and aPTT, serum electrolytes, and renal function should occur in parallel 1, 4
• A neurological assessment, including documentation of the exact time of symptom onset and performance of the National Institutes of Health Stroke Scale (NIHSS), should also be conducted 4, 7, 8

Blood Pressure Management

• For ischemic stroke patients who are potential candidates for rtPA, blood pressure must be reduced to <185/110 mmHg before rtPA can be administered 1, 2
• For hemorrhagic stroke patients, different blood pressure targets apply to prevent hematoma expansion 5

Special Considerations

• In rural or limited resource settings, if CT is unavailable, immediate activation of emergency medical services for transfer to the nearest stroke center is recommended 3
• Advanced imaging such as MRI may be useful for detecting chronic hemorrhage and vascular malformations, but should not delay rtPA administration in eligible patients 1, 2, 5