MRA Neck With and Without Contrast — Dictation, Appropriateness, and Dose for Residents

1. Hook — Your Next Stroke Workup MRA

It’s a busy outpatient list. Next up is an MRA of the neck on a 40-year-old with a recent cryptogenic stroke. CTA was non-diagnostic due to a contrast allergy. The neurologist suspects a dissection or maybe fibromuscular dysplasia (FMD), and your attending wants a definitive answer. They’re not just looking for a stenosis percentage; they want to know if you saw the T1-hyperintense crescent of an intramural hematoma on the fat-sat sequences and if you’ve evaluated for the classic “string of beads.” This is where MRA shines, but the protocol has a lot of moving parts—vessel wall imaging, time-of-flight, and contrast-enhanced sequences. Getting the key findings into a clean, structured report under pressure is the name of the game.

When I was a fellow, I kept a browser tab open with bookmarks to all my key references. If you’re building your own toolkit, we’ve put together a bunch of calculators and templates in the residents and fellows resource hub that you might find useful.

2. What an MRA Neck Without and With IV Contrast Covers and What Attendings Look For

An MRA of the neck is the workhorse for non-invasive, radiation-free evaluation of the carotid and vertebral arteries, from the aortic arch up to the circle of Willis. It combines non-contrast techniques like time-of-flight (TOF) with contrast-enhanced 3D acquisitions and dedicated vessel-wall sequences. This multi-sequence approach allows for a comprehensive assessment that goes beyond simple luminal narrowing.

While CTA is faster in an acute stroke setting, MRA is the problem-solver. It’s preferred for surveillance in younger patients, for anyone with a contraindication to iodinated contrast, and especially when the clinical question involves the vessel wall itself (dissection, vasculitis).

Your attending will expect a report that systematically addresses:

• Aortic Arch and Great Vessels: Origin anatomy and any anomalies.
• Carotid Arteries: Degree of stenosis in the common, internal, and external carotids, graded using the NASCET method.
• Vertebral Arteries: Patency, dominance, and any stenosis, particularly at the origins.
• Vessel Wall Evaluation: Specific mention of any intramural hematoma (the hallmark of dissection) or concentric wall thickening/enhancement (suggesting vasculitis).
• Specific Morphologies: Presence of fibromuscular dysplasia, aneurysms, or other vascular abnormalities.
• Intracranial Vessels: A brief evaluation of the circle of Willis, typically from the TOF sequences.

3. Radiology Report Template for MRA Neck Without and With IV Contrast

This template provides a solid starting point. You can adapt it for your institution’s macros in PowerScribe or other dictation software. The key is to be systematic, covering each major vessel segment and addressing the specific clinical question.

Technique

Multiplanar, multisequence MRI of the neck was performed without and with intravenous contrast. Sequences included axial T1 and T2-weighted fat-saturated images, 3D time-of-flight (TOF) MRA, and 3D contrast-enhanced MRA of the neck vessels from the aortic arch through the circle of Willis. A total of [X] mL of [Contrast Agent Name] was administered intravenously. Post-processing included maximum intensity projection (MIP) and multiplanar reformatted images.

Findings

Aortic Arch: [Describe arch anatomy, e.g., Left-sided arch with standard 3-vessel branching pattern. No evidence of stenosis, aneurysm, or dissection at the great vessel origins.]

Common Carotid Arteries: The bilateral common carotid arteries are patent without significant stenosis or plaque.

Carotid Bifurcations and Internal Carotid Arteries:
Right: [Describe stenosis using NASCET criteria, e.g., Mild (1-29%), Moderate (30-69%), or Severe (>70%) stenosis at the carotid bulb. Describe plaque morphology if relevant. Note presence/absence of dissection flap or intramural hematoma.]
Left: [Describe stenosis using NASCET criteria, e.g., Mild (1-29%), Moderate (30-69%), or Severe (>70%) stenosis at the carotid bulb. Describe plaque morphology if relevant. Note presence/absence of dissection flap or intramural hematoma.]

External Carotid Arteries: The bilateral external carotid arteries are patent.

Vertebral Arteries:
Right: [Describe origin, course, and caliber. Note dominance. e.g., The right vertebral artery is dominant and patent throughout its course without significant stenosis.]
Left: [Describe origin, course, and caliber. Note dominance. e.g., The left vertebral artery is hypoplastic/codominant and patent.]

Intracranial Vessels: The circle of Willis appears grossly intact based on the TOF sequence. The visualized portions of the intracranial arteries are patent.

Vessel Walls (T1/T2 Fat-Sat): No evidence of crescentic T1 hyperintensity to suggest intramural hematoma. No significant concentric vessel wall thickening or edema is seen.

Extravascular Structures: The visualized portions of the thyroid gland, cervical soft tissues, and cervical spine are unremarkable.

Impression

1. [Summarize the most critical finding first, e.g., Severe stenosis (70-80%) of the proximal left internal carotid artery, as measured by NASCET criteria.]
2. [Comment on other significant findings, e.g., No evidence of carotid or vertebral artery dissection. No features of fibromuscular dysplasia.]
3. [If stenosis is mild or moderate, state that, e.g., Mild atherosclerotic plaque at the bilateral carotid bifurcations without hemodynamically significant stenosis.]

4. Free Template Sources

Building a personal library of high-quality templates is a rite of passage in residency. Before you start from scratch, know that two great free repositories exist, curated by radiologists for radiologists. They are excellent resources for finding standardized language for almost any study you’ll encounter.

• RadReport.org: Maintained by the RSNA, this is a comprehensive library of peer-reviewed templates covering all subspecialties.
• Radiology Templates (AU): An excellent, user-friendly site from Australia with a wide range of practical templates for day-to-day work.

They’re great for grabbing a structure, but the next step is making that structure work for you without slowing you down.

5. The Next-Level Move: Free-Form Dictation to Structured Report

The challenge with templates isn’t finding them; it’s using them efficiently under pressure. Tabbing through a dozen fields in a macro for a complex study can be slower than just dictating what you see. This is where AI-driven tools can change your workflow.

Instead of meticulously filling out a template, you can dictate your positive findings in free form—”Severe stenosis at the left carotid bulb with a T1 hyperintense crescent in the vessel wall consistent with dissection and intramural hematoma.” The AI then parses this, identifies the key findings, and generates a fully structured report. Tools like GigHz Precision AI are designed to use ACR and SIR standard templates, ensuring your report is clean, consistent, and contains the information your attending and the referring clinician need. It helps surface the right language and ensures critical elements, like stenosis grading or dissection features, are clearly documented in the final impression.

6. When Should You Order an MRA Neck Without and With IV Contrast? ACR Appropriateness Criteria

Deciding between MRA, CTA, and ultrasound depends heavily on the clinical scenario. The American College of Radiology (ACR) provides evidence-based guidelines to help with these decisions. For cerebrovascular disease, MRA of the neck is often a key player.

According to the ACR Appropriateness Criteria for Cerebrovascular Diseases-Stroke and Stroke-Related Conditions, MRA neck is “Usually Appropriate” for a wide range of scenarios. This includes the initial workup of an adult with a transient ischemic attack (TIA) or a recent ischemic infarct (both less than and greater than 24 hours old). It’s also “Usually Appropriate” for surveillance of a prior infarct or known asymptomatic carotid stenosis.

For suspected cervical vascular dissection, MRA is a primary imaging modality and is rated “Usually Appropriate.” This is where its ability to directly visualize intramural hematoma on T1 fat-saturated sequences gives it an edge. In contrast, for acute stroke or trauma, CTA is often preferred due to its speed and accessibility. Other valuable alternatives include Doppler ultrasound, which is excellent for initial screening of carotid stenosis but is operator-dependent, and catheter angiography, which remains the gold standard and allows for intervention.

7. How Much Radiation Does an MRA Neck Without and With IV Contrast Deliver?

One of the primary advantages of Magnetic Resonance Angiography is the complete absence of ionizing radiation.

The estimated effective radiation dose for an MRA of the neck is 0 mSv. This makes it an ideal imaging modality for younger patients, individuals requiring serial surveillance studies for conditions like FMD or dissection follow-up, and pregnant patients where radiation exposure to the fetus is a concern.

This lack of radiation is a key factor when choosing MRA over CTA for non-emergent indications or for follow-up imaging.

8. MRA Neck Without and With IV Contrast Imaging Protocol — Phases, Contrast, and Reconstructions

A robust MRA neck protocol is designed to evaluate both the vessel lumen and the vessel wall. It starts with non-contrast sequences to look for hematoma and edema, followed by flow-based TOF MRA, and finally a dynamic contrast-enhanced MRA for the most accurate luminal assessment.

The core of the protocol involves acquiring high-resolution 3D datasets that can be reconstructed in any plane. Contrast timing is critical and is typically achieved using a test bolus or automated bolus tracking over the aortic arch.

Contrast: 0.1-0.2 mmol/kg of a macrocyclic gadolinium-based agent is injected at 2 mL/sec.

Common Protocol Pitfalls: The most common pitfall is misinterpreting flow artifacts on TOF MRA as true stenosis. TOF sequences are prone to signal loss (spin dephasing) in areas of turbulent flow, such as the carotid bulb, which can significantly overestimate the degree of stenosis. Always correlate with the contrast-enhanced MRA source images, which are more reliable for quantifying stenosis in the cervical vessels.

9. The 3-Months-Free Residents Offer

3+ months free for radiology residents and fellows

If you want to look like a rockstar on your reports, we’ve got an offer for you. The typical workflow of finding a template, opening a macro, and tabbing through fields is slow. Instead, you can dictate your positive findings in free form, and our AI will generate a clean, structured report using ACR and SIR templates. The appropriate clinical decision support fires automatically, helping you get the classification right every time.

All we ask in return is your feedback so we can keep improving the product for trainees.

To sign up, just let us know:

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

It’s simple. No credit card, no long forms. Reply to the application with those three items, and we’ll get you set up. You can apply for the residents free-access program here.

10. Frequently Asked Questions (FAQ)

Is GigHz Precision AI HIPAA-compliant?

Yes. The platform is designed for de-identified workflows by default. No protected health information (PHI) is required to use the tool to structure your findings, and no PHI is ever stored.

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

No. GigHz Precision AI is browser-based and requires no local installation or special permissions. It works on any modern web browser, including the one on your call-room computer or personal iPad.

Does it work with PowerScribe or other dictation systems?

Yes. You can use it alongside any dictation system. Most residents dictate their free-form findings as usual, then copy the generated structured report from the browser into their PACS/RIS. It’s a simple copy-paste workflow.

Can I use this on my phone or iPad?

Absolutely. The platform is fully responsive and works well on mobile devices, making it easy to use on the go or in different reading rooms without being tied to a specific workstation.

Can I customize the templates?

Yes, customization is a core feature. While the system comes pre-loaded with ACR and society-recommended templates, you can create, modify, and save your own templates to match your personal preferences or your institution’s specific formatting requirements.

What happens after I finish residency or fellowship?

The free access program is specifically for trainees. After you graduate, you can transition to a standard attending plan. We offer discounts for recent graduates to help you get started in your new role.

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.

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