Vessel Wall MRI Ordering Guides
Select the clinical question below for indications and exact Epic orders.
Brain VWI: Stroke & VasculopathyIntracranial atherosclerosis, CNS vasculitis, RCVS, dissection
✓ When to order
- Routine CTA, MRA, or DSA has identified an abnormality requiring vessel wall characterization.
- Differentiate intracranial atherosclerosis, CNS vasculitis, RCVS, intracranial dissection, or another vasculopathy.
- Evaluate recurrent or otherwise unexplained ischemic stroke when an intracranial vascular cause is suspected.
× When not to order
- As a first-line screening examination.
- Before routine CTA or MRA has raised a specific diagnostic question.
- Concurrently with Neck VWI Vasculitis during the initial workup unless discussed with neuroradiology.
Epic ordering instructions
Order both examinations:
Includes: vessel wall imaging, DWI, SWI, FLAIR, and T2-weighted imaging.
Important: Do not routinely order Brain VWI and Neck VWI Vasculitis together. The combined examinations are often too long for patients to tolerate.
Shorter option: A limited protocol with pre- and postcontrast VWI, SWI, and T2-weighted imaging is available for selected patients. Discuss with neuroradiology.
Brain VWI: Subarachnoid HemorrhageAngiogram-negative atraumatic SAH
✓ When to order
- Angiogram-negative atraumatic SAH after the recommended CTA/DSA evaluation.
- As an adjunct to evaluate for a blister or perforator aneurysm, dissecting aneurysm, occult AVF/AVM, or the culprit among multiple aneurysms.
× Important limitations
- VWI does not replace the recommended acute SAH diagnostic workup.
- DSA remains the reference standard for AVF/AVM evaluation.
- MRA neck is not the correct order to screen for a cervicomedullary AVF/AVM.
Epic ordering instructions
Order both examinations:
Includes: vessel wall imaging, DWI, SWI, FLAIR, and T2-weighted imaging.
Optional for posterior fossa SAH: MR Cervical Spine WWO may be added to screen for a cervicomedullary AVF/AVM. This requires an additional approximately 30-minute MR slot.
Neck VWI: Arterial DissectionCervical carotid or vertebral artery dissection
✓ When to order
- Concern for cervical carotid or vertebral artery dissection.
- Routine CTA or MRA neck has already raised a specific question.
- Further characterization of mural hematoma or vessel wall abnormality is needed.
× When not to order
- As the initial screening examination for suspected dissection.
- Without identifying the artery and segment of concern.
Epic ordering instructions
Order one examination:
In the comments: specify the artery and segment of concern: carotid versus vertebral; origin, mid-cervical, or skull base/craniocervical segment.
Neck VWI: Carotid PlaqueIntraplaque hemorrhage, unstable plaque, carotid web
✓ When to order
- Concern for unstable carotid plaque or intraplaque hemorrhage.
- Concern for carotid web.
- Routine CTA or MRA neck has raised a specific diagnostic question.
× When not to order
- As a first-line carotid screening examination.
- When routine vascular imaging has not identified a lesion requiring further characterization.
Epic ordering instructions
Order one examination:
Neck VWI: VasculitisCarotid or vertebral arteritis, TIPIC
✓ When to order
- Concern for carotid or vertebral artery vasculitis.
- Concern for TIPIC syndrome (carotidynia).
- Routine CTA or MRA neck has raised a specific question.
× When not to order
- As a first-line screening examination.
- Concurrently with Brain VWI during the initial CNS vasculitis workup unless discussed with neuroradiology.
Epic ordering instructions
Order one examination:
Important: Brain VWI and Neck VWI together are often too long for patients to tolerate. Prioritize the region most likely to answer the immediate clinical question.
Giant Cell Arteritis VWI/MRATemporal and occipital scalp arteries
✓ When to order
- Evaluate suspected temporal arteritis involving the temporal and occipital scalp arteries.
- The patient can undergo imaging on a 3T scanner.
× Important limitations
- This examination must be performed at 3T to achieve the required spatial resolution.
- Patients with a contraindication to 3T cannot undergo this examination.
- The scalp VWI component does not replace brain MRI when stroke is suspected.
Epic ordering instructions
Order one examination:
TOF MRA also screens for intracranial vasculopathy.
Add when clinically indicated: MR Brain/Rapid Stroke for concern for stroke; routine MR Orbits for visual deficits.
Clinical context: Temporal artery biopsy remains an accepted diagnostic standard. Use imaging findings together with the clinical and laboratory evaluation.