Vascular & Stroke
Blunt Cerebrovascular Injury: It Hides — Screen and Grade
Fellowship-level neuroradiology teaching by E. Brooke Schrickel, MD. Open this topic in the interactive reading room →
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Core clinical idea
Blunt cerebrovascular injury hides: the classic patient has a deficit delayed or out of proportion to the scan because a torn intima emboli before the vessel looks dramatic. Screen, grade, and respect that low grades climb — read qualifying neck trauma as a lesion that hasn't shown its damage yet.
Bottom line
Trauma vessels lie low — screen, interrogate them along their course, grade for progression, and know where CTA goes blind.
Core workstation questions
- Does this patient meet screening criteria — and have I interrogated both carotids and both verts along their full course?
- What grade, and is it the kind that progresses (1-2)? Is it dissection or pseudoaneurysm?
- Is the vertebral artery adequately seen within the transverse foramina, or does the bony cage need MRA?
- Is this Grade 1 irregularity real injury, or vasospasm/tortuosity near the styloid?
- Does the wall need a black-blood MR to show an intramural hematoma the lumen study can't?
What changes reporting / management
- Screen by Denver-type criteria (signs/symptoms or high-energy mechanism/associated injuries) -> CTA first-line for both blunt and penetrating neck trauma; DSA is gold standard reserved for follow-up/intervention; MR usually not first-line acutely.
- Report the Biffl-type grade (1 minimal <25%, 2 >25%/flap/subocclusive thrombus, 3 pseudoaneurysm, 4 occlusion, 5 transection) AND the progression risk for low grades, since it drives antithrombotic therapy and follow-up timing.
- Distinguish dissection (blood within wall layers -> luminal stenosis) from pseudoaneurysm (outer-layer disruption, contained extraluminal blood) — different grades, different management.
- Name CTA blind spots: vertebral injury inside the transverse foramen (better on MRA) and Grade 1 irregularity vs. vasospasm/tortuosity near bone; reach for black-blood MR when the wall/intramural hematoma is the question.
- Lower the threshold to interrogate vessels and add MR when the clinical picture is out-of-proportion (e.g., Horner's after minor mechanism).
Practical traps
- Clearing the neck vessels off a normal initial brain CT — the deficit lags the injury.
- Calling a vertebral artery clean off CTA alone when a transverse-foramen fracture obscures it.
- Reading Grade 1 luminal irregularity as definite injury when traumatic vasospasm or tortuosity near the styloid mimics it.
- Treating the grade as a one-time snapshot rather than a progression risk needing follow-up.
Teaching pearls
- A normal brain CT doesn't clear the neck — the deficit lags the injury.
- Low-grade BCVI climbs — grade it as a behavior, not a snapshot.
- Dissection is blood in the wall; pseudoaneurysm is contained blood outside it.
- The vert in the transverse foramen is CTA's blind spot — let MRA see it.
- Out-of-proportion deficit after minor trauma (Horner's, droopy lid) is dissection until proven otherwise.
Teaching visuals
Source lectures
- Noninvasive Angiography in Traumatic Vascular Injury
Educational material for radiology residents and neuroradiology fellows. Nothing here drives individual patient care, and it contains no patient data.