Imaging recommendation · Neuro · Head & Neck

Headache, new-onset, no red flags

Q: What's the alternative imaging for headache, new-onset, no red flags when mri unavailable / acute setting?

CT — CT Head without contrast (no contrast).

Q: What's the alternative imaging for headache, new-onset, no red flags when concern for vascular cause?

MRI — MRA Brain (no contrast).

Recommended: MRI Brain without contrast is the preferred imaging study for headache, new-onset, no red flags. Non-contrast MRI is the modality of choice for adult headache work-up after the acute setting is excluded.

Recommended study

MRI Brain without contrast

MRI No contrast Preferred Neuro · Head & Neck OutpatientAcute inpatient Reviewed 2026-03

Non-contrast MRI is the modality of choice for adult headache work-up after the acute setting is excluded. CT head is reserved for acute trauma or thunderclap presentation when MRI is unavailable.

If the default doesn't apply

MRI unavailable / acute setting

CT CT Head without contrast No contrast

Concern for vascular cause

MRI MRA Brain No contrast

Watch-outs

Thunderclap headache

CT head + LP or CTA to exclude SAH. Do not start with elective MRI.

Focal neuro deficit, fever, immunocompromised, age > 50

Add contrast (MRI w/ and w/o) and consider urgent imaging.

Pearls

True 'worst headache of life' deserves CT first, not MRI.
Migraine is a clinical diagnosis — imaging is for ruling out, not ruling in.