CTA Head and Neck (Carotid + COW) — Dictation, Appropriateness, and Dose for Residents

Stat CTA head and neck from the ED. 68-year-old with acute left-sided weakness, NIH stroke scale of 15. The non-contrast head CT is negative for a bleed. Now it’s on you to find the large-vessel occlusion (LVO) that’s driving this. The neurointerventional team is waiting for your call, and your attending expects a precise location of the clot, characterization of the collateral flow, and a clean impression. No pressure.

When I was a resident on neuro call, this was the study that made my heart rate jump. It’s not just about finding the clot; it’s about systematically evaluating every vessel from the arch to the vertex under extreme time pressure. This guide is built to give you a solid framework for that read, whether it’s a stat stroke code or a TIA workup from clinic. For more tools like this, check out our free residents and fellows resource hub.

What a CTA Head and Neck Covers and What Attendings Look For

A Computed Tomography Angiogram (CTA) of the head and neck is the workhorse for evaluating the arterial system from the aortic arch through the intracranial circulation. It requires precise contrast timing to light up the arteries and provides high-resolution detail of the vessel walls and lumen. In the acute setting, its primary job is to confirm or exclude a condition that requires immediate intervention.

Your attending expects a systematic evaluation that answers these key clinical questions:

• Is there an acute large-vessel occlusion in the anterior or posterior circulation?
• Is there hemodynamically significant carotid or vertebral artery stenosis?
• Are there signs of a dissection, such as an intimal flap or pseudoaneurysm?
• Is there an unruptured or ruptured intracranial aneurysm?
• Are there findings of vasculitis, like vessel wall thickening or beading?
• Are there any key vascular variants (e.g., fetal PCA, fenestrated basilar)?

Common indications include acute stroke symptoms, transient ischemic attack (TIA) workup, suspected subarachnoid hemorrhage, trauma with concern for blunt cerebrovascular injury (BCVI), and pulsatile tinnitus.

Radiology Report Template for CTA Head and Neck (Carotid + Circle of Willis)

This template provides a reliable structure. Start at the arch and work your way up. Be systematic every time, and you won’t miss the subtle dissection or the tiny AcomA aneurysm.

Technique

CTA of the head and neck was performed with intravenous contrast administration. Images were acquired from the aortic arch through the vertex of the skull. Multiplanar reformations, including axial, coronal, sagittal, and maximum intensity projections (MIPs), were reviewed. 3D volumetric renderings were also evaluated.

Contrast: [e.g., 75 mL of Iohexol 350] administered via a power injector in the right antecubital vein.

Findings

AORTIC ARCH AND GREAT VESSEL ORIGINS: The aortic arch is [e.g., left-sided, right-sided, bovine]. The origins of the brachiocephalic, left common carotid, and left subclavian arteries are patent. No evidence of dissection, significant stenosis, or intramural hematoma.

EXTRACRANIAL CAROTID ARTERIES:
Right Common Carotid Artery: Patent throughout its course.
Right Carotid Bifurcation: [Describe plaque burden and estimate stenosis using NASCET criteria, e.g., “Mild calcified plaque causing less than 50% stenosis.”]
Right Internal Carotid Artery (Cervical Segment): Patent. No dissection or fibromuscular dysplasia.
Right External Carotid Artery: Patent.
Left Common Carotid Artery: Patent throughout its course.
Left Carotid Bifurcation: [Describe plaque burden and estimate stenosis using NASCET criteria.]
Left Internal Carotid Artery (Cervical Segment): Patent. No dissection or fibromuscular dysplasia.
Left External Carotid Artery: Patent.

EXTRACRANIAL VERTEBRAL ARTERIES:
Right Vertebral Artery: [e.g., “Arises from the right subclavian artery. Dominant. Patent throughout its course without significant stenosis or dissection.”]
Left Vertebral Artery: [e.g., “Arises from the left subclavian artery. Hypoplastic. Patent.”]

INTRACRANIAL CIRCULATION:
Intracranial Vertebral Arteries and Basilar Artery: Confluence is normal. The basilar artery is patent to its tip. No significant stenosis or occlusion.
Posterior Cerebral Arteries (PCAs): P1 and P2 segments are patent bilaterally.
Circle of Willis: [e.g., “Intact and patent. No evidence of aneurysm.”]. Comment on variants like fetal origin of the PCA or absence of communicating arteries.
Anterior Cerebral Arteries (ACAs): A1 and A2 segments are patent bilaterally. No filling defects.
Middle Cerebral Arteries (MCAs): M1 and M2 segments are patent bilaterally. No evidence of large vessel occlusion.
Distal Vasculature: No distal filling defects to suggest embolic occlusion.

INCIDENTAL FINDINGS:
Brain Parenchyma (on angio images): No acute large territorial infarct or hemorrhage.
Bones: No acute fracture.
Visualized portions of the neck soft tissues, sinuses, and orbits are unremarkable.

Impression

1. No evidence of acute large vessel occlusion in the anterior or posterior circulation.
2. [e.g., “Mild atherosclerotic disease of the carotid bifurcations bilaterally, without hemodynamically significant stenosis. The maximal stenosis is less than 50% at the left carotid bifurcation.”]
3. No evidence of intracranial aneurysm, vascular malformation, or dissection.

Free Template Sources for Radiology Residents

Before we talk about AI-driven tools, it’s worth knowing that two great free repositories exist for radiology templates. They are excellent for finding a starting point for less common studies or for seeing how other institutions structure their reports.

• RadReport.org: Curated by the Radiological Society of North America (RSNA), this is a comprehensive library of peer-reviewed templates covering nearly every modality and subspecialty.
• Radiology Templates (AU): An Australian-maintained library that offers a clean interface and a solid collection of general and subspecialty templates.

These are fantastic resources, especially early in training. The main challenge is manually finding, copying, and pasting them into your dictation system during a busy shift.

The Next-Level Move: AI-Powered Structured Reporting

The classic workflow is to dictate your positive findings and then manually structure them into a clean report, often tabbing through a pre-built macro. This works, but it can be slow and rigid. The alternative is to dictate your findings in free form and let an AI tool handle the structuring for you.

This is what GigHz Precision AI is designed for. You can dictate naturally—”70% stenosis at the left ICA origin with calcified plaque”—and the platform generates a fully structured report based on ACR and SIR standards. It helps ensure you’ve included all the key elements your attending is looking for without forcing you into a rigid, click-box-style template. It’s about streamlining the process from raw observation to finalized, coherent report.

When Should You Order a CTA Head and Neck? ACR Appropriateness Criteria

The American College of Radiology (ACR) provides evidence-based guidelines to help clinicians choose the right test for the right reason. For cerebrovascular imaging, the choice of CTA, MRA, or ultrasound depends heavily on the clinical scenario.

For a patient presenting with acute stroke symptoms, a non-contrast CT of the head is the first step to rule out hemorrhage. If no bleed is seen and the patient is a candidate for intervention, a CTA of the head and neck is “Usually Appropriate” per the ACR’s “Cerebrovascular Diseases-Stroke and Stroke-Related Conditions” guidelines. This is the fastest and most robust way to identify a large-vessel occlusion for potential thrombectomy.

In the non-acute setting, such as for a TIA workup or evaluation of symptomatic carotid stenosis, a CTA of the head and neck is also “Usually Appropriate” according to the “Cerebrovascular Disease” topic. It provides a comprehensive view of both the extracranial and intracranial vessels.

For suspected subarachnoid hemorrhage with a negative non-contrast CT head, a CTA of the head is “Usually Appropriate” to look for a causative aneurysm. Alternatives like MRA are considered when iodinated contrast is contraindicated, while carotid ultrasound is primarily a screening tool for bifurcation stenosis and doesn’t evaluate the intracranial vessels. Catheter angiography remains the gold standard but is invasive and typically reserved for treatment planning.

How Much Radiation Does a CTA Head and Neck Deliver?

A common patient question is about radiation dose. A typical CTA of the head and neck delivers an effective dose of 3-7 mSv. This places it in the low-to-moderate dose category for CT scans, comparable to a few years of natural background radiation that we all receive annually.

Modern CT scanners use several dose-reduction techniques, such as automated tube current modulation and iterative reconstruction algorithms, to keep the dose as low as reasonably achievable (ALARA) while maintaining diagnostic image quality. The target CTDIvol (CT Dose Index volume) is generally kept under 50 mGy. While it’s more radiation than a plain head CT, the diagnostic yield in the right clinical setting, like an acute stroke, far outweighs the risk.

CTA Head and Neck Imaging Protocol — Phases, Contrast, and Reconstructions

A successful CTA hinges on a precise, well-timed protocol. The goal is to capture a pure arterial phase with dense opacification of the vessels from the aortic arch to the distal intracranial branches, minimizing venous contamination. This requires a rapid contrast injection and accurate bolus tracking.

The scan itself is incredibly fast, often taking only 8-12 seconds. A 20-gauge or larger IV is placed in the right antecubital fossa to avoid streak artifact from dense contrast in the left brachiocephalic vein, which can obscure the great vessel origins.

A common pitfall is improper contrast timing, leading to a “mixed” arteriovenous phase that can obscure vessel detail, especially intracranially. Another is streak artifact from a left-sided IV, which is why a right-sided injection is strongly preferred.

The 3-Months-Free Offer for Radiology Residents and Fellows

3+ months free for radiology residents and fellows

Look like a rockstar on your reports. With GigHz Precision AI, you can dictate your positive findings in free form, and the AI generates a structured report using ACR and SIR templates. The appropriate clinical decision support, like LI-RADS or Bosniak classifications, fires automatically based on your dictation.

All we ask in return is your feedback so we can keep improving the product for trainees. The signup is simple—no credit card, no long forms. Just provide the following three items:

1. Your PGY year (e.g., PGY-2, PGY-4)
2. Your training type (radiology residency or fellowship specialty)
3. Your training program / hospital name

To get started, apply for the residents free-access program and reply to the application email with those three details.

Free GigHz Tools That Pair With This Article

Three free tools that complement the material above:

• ACR Appropriateness Criteria Lookup — Type an indication or clinical scenario in plain language and get the imaging studies the ACR rates for it, with adult and pediatric radiation levels. Built directly from 297 ACR topics, 1,336 clinical variants, and 15,823 procedure ratings.
• GigHz Imaging Protocol Library — A searchable library of 131 imaging protocols with the physics specs surfaced and the matching ACR Appropriateness Criteria alongside. Plain-English narratives readable in 60 seconds, organized by modality.
• GigHz Radiation Dose Calculator — Pick the imaging studies a patient has had and see total dose in millisieverts (mSv) with comparisons to natural background radiation, transatlantic flights, and chest X-rays. Useful for shared decision-making.

Frequently Asked Questions

Is GigHz Precision AI HIPAA-compliant?

Yes. The platform is designed for de-identified workflows by default. You dictate findings, not raw patient data. It operates securely within a HIPAA-compliant cloud environment, and no PHI is required or stored to generate a report.

Do I need my hospital’s IT department to set this up?

No. GigHz Precision AI is a browser-based tool. There is no software to install on hospital machines. It works on any modern web browser, including the one on your call-room computer or personal iPad.

How does this work with PowerScribe or other dictation systems?

It works alongside your existing system. Most residents dictate their findings into the GigHz web app, let the AI generate the structured report, and then copy/paste the final, clean text into PowerScribe or their EMR. It’s a simple copy-paste workflow.

Can I use this on my phone or iPad?

Yes, the platform is fully responsive and works well on mobile and tablet devices, making it useful for reviewing templates or generating reports on the go.

Can I customize the templates?

Yes. While the system comes pre-loaded with ACR and society-standard templates, you can create, save, and modify your own personal templates to match your preferences or your institution’s specific style.

What happens after my residency or fellowship ends?

The free access program is specifically for trainees. After you graduate, you can transition to a standard plan for practicing radiologists. We offer discounts for recent graduates to help ease the transition into practice.

Reviewed by Pouyan Golshani, MD, Interventional Radiologist — May 7, 2026