Which imaging modality is typically used first in unstable ED seizure patients?

• A. MRI of the brain
• B. CT scan of the head
• C. EEG in the ED
• D. PET scan

Answer: (B)

In unstable ED seizure patients, the priority is rapid identification of life-threatening brain emergencies. A non-contrast CT scan of the head is the imaging study of choice because it can be done within minutes, is widely available in most EDs, and quickly reveals acute intracranial hemorrhage, mass effect, or hydrocephalus that would drive urgent management. MRI provides more detail for certain lesions but takes longer and requires moving a potentially unstable patient, making it impractical as the initial test. EEG in the ED isn’t an imaging study and won’t address acute structural issues, while PET isn’t used for emergent evaluation. So, the first imaging step is the non-contrast CT head.