Imaging recommendation · Neuro · Head & Neck

Acute focal neurologic deficit

Q: What's the alternative imaging for acute focal neurologic deficit when window > 24 h with stable patient?

MRI — MRI Brain with DWI (no contrast).

Q: What's the alternative imaging for acute focal neurologic deficit when iodinated contrast contraindicated?

MRI — MRI/MRA Brain + Neck (iv contrast).

Recommended: CT Head non-contrast + CTA Head/Neck + CT Perfusion is the preferred imaging study for acute focal neurologic deficit. Standard acute neuro protocol.

Recommended study

CT Head non-contrast + CTA Head/Neck + CT Perfusion

CT IV contrast Preferred Neuro · Head & Neck EmergencyAcute inpatient Reviewed 2026-03

Standard acute neuro protocol. Add MRI brain if intervention decision unclear, or beyond the standard window for late-presenters.

If the default doesn't apply

Window > 24 h with stable patient

MRI MRI Brain with DWI No contrast

Iodinated contrast contraindicated

MRI MRI/MRA Brain + Neck IV contrast

Watch-outs

Time is brain

Imaging should not delay activation of stroke team — interpret on the table.

Renal function

Do not delay stroke CT for creatinine in the eligible window; benefit outweighs CI-AKI risk per ACR.

Pearls

Perfusion mismatch defines the salvageable penumbra — discuss with NeuroIR for late-window LVO.
Posterior circulation strokes are commonly missed on initial CT — have a low threshold for MRI.