MRI Brain Stroke Protocol — Dictation, Appropriateness, and Dose for Residents

The MRI Brain Stroke Protocol: A Dictation Template for On-Call Residents

Code Stroke. The ED attending is on the phone, the neurologist is on their way to the reading room, and you’ve just opened the fast brain MRI on your PACS. It’s a “wake-up stroke,” so the last-known-well time is a black box. The team needs to know three things from you, fast: Is there an acute infarct? Is there a DWI-FLAIR mismatch suggesting they’re in the tPA window? And is there a large vessel occlusion (LVO) for the IR team to chase?

This is a high-stakes read where speed and precision are everything. Your attending expects a structured report that answers the clinical question directly. When I was a resident, fumbling for the right phrasing on a critical finding was my biggest fear. The goal is to have a framework ready so you can focus on the images, not the words. For more guides like this, check out our free trainee calculators and references.

What an MRI Brain Stroke Protocol Covers and What Attendings Look For

A rapid, non-contrast (or selectively post-contrast) MRI protocol is the gold standard for identifying acute ischemic stroke, especially in the posterior fossa where CT is limited. It’s designed to be completed in under 30 minutes, providing a comprehensive map of ischemic injury, vessel status, and potential stroke mimics.

Your attending, and more importantly the clinical team, expects your report to definitively answer:

• Acute Infarct: Is there true restricted diffusion (bright on DWI, dark on ADC)? Where is it, and in which vascular territory?
• Stroke Age (Time Window): Is there a DWI-FLAIR mismatch? A positive DWI finding without a corresponding FLAIR signal suggests the stroke occurred within the last 4.5 hours, potentially making the patient eligible for thrombolysis even with an unknown last-known-well time.
• Hemorrhage Risk: Are there microbleeds on the T2* or SWI sequence? A high burden (>10) may increase the risk of hemorrhagic transformation with tPA.
• Vessel Occlusion: Does the MRA show an LVO in the ICA, M1 segment, or basilar artery? This is the target for mechanical thrombectomy.
• Penumbra vs. Core (if PWI is done): Is there a significant mismatch between the perfusion defect and the diffusion-restricted core? A large penumbra supports intervention, especially in extended time windows.
• Stroke Mimics: Could this be something else? An underlying tumor, abscess, seizure-related change, or demyelinating plaque can sometimes present with stroke-like symptoms.

Radiology Report Template for MRI Brain Stroke Protocol

This template provides a reliable starting point. Dictate your positive findings, and use the placeholders to ensure you cover all the key elements the clinical team needs.

Technique

Multiplanar, multisequence MRI of the brain was performed without intravenous contrast, utilizing a stroke protocol. Sequences include DWI, ADC, FLAIR, T2-weighted, T2*/SWI, and 3D TOF MRA of the circle of Willis.

(Modify as needed if contrast or perfusion imaging was administered.)

Findings

DIFFUSION-WEIGHTED IMAGING: There is focal restricted diffusion involving the [LOCATION, e.g., left parietal lobe, right cerebellar hemisphere] in the expected vascular territory of the [e.g., left MCA, right PICA]. The corresponding ADC map confirms true restricted diffusion. No other areas of restricted diffusion are identified.

FLAIR: There is [no corresponding FLAIR signal abnormality / subtle corresponding FLAIR hyperintensity] in the region of restricted diffusion. [Describe any chronic findings, such as white matter ischemic change, old infarcts, or encephalomalacia.]

T2*/SWI: There is no evidence of acute intracranial hemorrhage. There are [number, e.g., 2] foci of susceptibility artifact consistent with microhemorrhages in the [LOCATION, e.g., bilateral basal ganglia]. No evidence of venous sinus thrombosis.

MRA BRAIN (TOF): The major intracranial arteries are patent. [OR] There is an abrupt cutoff of the [VESSEL, e.g., M1 segment of the left middle cerebral artery] consistent with large vessel occlusion. The remaining circle of Willis is [patent/shows fetal PCA/etc.].

OTHER SEQUENCES: The visualized paranasal sinuses and mastoid air cells are clear. The ventricular system is normal in size and configuration. No mass effect or midline shift.

Impression

1. Acute ischemic infarct involving the [LOCATION] in the [VASCULAR TERRITORY], demonstrating restricted diffusion.
2. [POSITIVE or NEGATIVE] DWI-FLAIR mismatch, suggesting the infarct is likely [less than 4.5 hours / greater than 4.5 hours] in age.
3. [No evidence of / Occlusion of the (VESSEL)] on MRA, consistent with large vessel occlusion.
4. [No / Number of] chronic microhemorrhages. No acute intracranial hemorrhage.

Free Template Sources for Residents and Fellows

Building a personal template library is a rite of passage. Before you build everything from scratch, know that two great free repositories exist, curated by radiologists for radiologists. They are excellent sources for common and uncommon studies alike.

• RadReport.org: Maintained by the RSNA, this is the most comprehensive library of peer-reviewed, structured templates available. (https://radreport.org/)
• Radiology Templates (AU): A fantastic, user-friendly library maintained by Australian radiologists with clean, practical templates. (https://www.radiologytemplates.com.au/home-page/)

The Next-Level Move: AI-Assisted Structured Reporting

Templates are static. They’re a great starting point, but they don’t adapt to your findings. The next step in reporting efficiency is letting the software do the structuring for you. Instead of navigating a complex template, you can simply dictate the positive findings in free form—”acute left MCA infarct with restricted diffusion and a positive DWI-FLAIR mismatch”—and the AI handles the rest.

Tools like GigHz Precision AI are designed for this workflow. It takes your free-form dictation of key findings and organizes it into a clean, structured report based on pre-loaded ACR and society-backed templates. It helps ensure your impression directly answers the clinical question and includes all the necessary follow-up recommendations, without you having to manually type or click through a dozen fields. This approach streamlines the reporting process, especially for complex, multi-finding studies.

When Should You Order an MRI Brain Stroke Protocol? ACR Appropriateness Criteria

The decision between CT and MRI for acute stroke often comes down to speed and availability. However, the American College of Radiology (ACR) provides clear guidance on when MRI is the preferred initial study. According to the ACR Appropriateness Criteria for Cerebrovascular Diseases-Stroke and Stroke-Related Conditions, MRI is a cornerstone of diagnosis.

For an adult presenting with a focal neurologic deficit where acute ischemic stroke is suspected, an MRI brain stroke protocol is rated as Usually Appropriate. This also holds true for patients with a clinical transient ischemic attack (TIA) whose symptoms have resolved, as MRI is highly sensitive for small infarcts that a CT might miss. The same “Usually Appropriate” rating applies whether the suspected infarct is less than 24 hours old or greater than 24 hours old, highlighting MRI’s utility across the stroke timeline.

In cases of suspected venous sinus thrombosis or cervical vascular dissection, MRI/MRV and MRA are also considered Usually Appropriate initial imaging modalities. CT and CTA remain critical alternatives, especially when MRI is not immediately available or contraindicated, and are often the first-line choice in many emergency departments due to their speed.

MRI Brain Stroke Protocol Imaging Protocol — Phases, Contrast, and Reconstructions

A successful stroke MRI protocol is all about speed and diagnostic yield. The goal is to acquire the most critical sequences in the shortest possible time, often in an abbreviated fashion focusing on diffusion, hemorrhage, and vessel patency. The entire scan should ideally be completed in less than 20-30 minutes from patient arrival.

The core sequences are essential, while perfusion and post-contrast imaging are often reserved for specific clinical questions, like evaluating for extended-window thrombectomy or ruling out stroke mimics.

Common protocol pitfalls: The biggest variables are speed and the inclusion of perfusion imaging (PWI). Many centers run an abbreviated protocol (DWI, FLAIR, T2*, MRA only) to maximize speed for acute stroke alerts. The decision to include PWI is often institution-dependent, with some centers using it routinely for extended-window thrombectomy evaluation and others relying on clinical and anatomic criteria alone.

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

Look like a rockstar on your reports — dictate positive findings in free form, and the AI generates a structured report using ACR + SIR templates with the appropriate clinical decision support firing automatically.

We’re offering 3+ months of free access to GigHz Precision AI for all radiology trainees. All we ask in return is your feedback so we can keep improving the product for the next generation of radiologists.

Signup is simple. No credit card, no long forms. To apply, just provide these 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

Ready to give it a try? Apply for the residents free-access program and we’ll get you set up.

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. It processes the clinical content of your dictation without requiring Protected Health Information (PHI). All data is handled within a secure, HIPAA-compliant environment.

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

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

Does this replace PowerScribe or our existing dictation system?

No, it works alongside it. You can dictate your findings as you normally would. You then use the AI-generated structured report to paste into your PACS/RIS, ensuring your final report is clean, comprehensive, and follows best practices.

Can I use this on my phone or iPad?

Yes. The platform is fully responsive and works on mobile devices, making it easy to review templates or process a report from anywhere.

Can I customize the templates?

Yes. While the system comes pre-loaded with ACR and society-backed 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 my residency or fellowship ends?

We offer straightforward continuation plans for practicing radiologists. Your customized templates and settings will be saved, so you can transition seamlessly from training to practice without losing your workflow.

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