University of Pennsylvania

Penn Neuroradiology Vessel Wall Imaging

Center of Excellence

An advanced vessel wall MRI program providing expert clinical imaging, multidisciplinary consultation, education, and research for patients and clinicians across Penn Medicine.

Clinical Care Education Research

Founding Director

Jae W. Song, MD, MS

When & How to Order VWI

Select a clinical scenario below for guidance on when to order vessel wall MRI, the appropriate Epic examination(s), and site & scanner availability.

BRAIN VWI Stroke & Vasculopathy Brain vessel wall MRI/MRA
Clinical question

What is causing this patient’s intracranial arterial narrowing or ischemic stroke?

When to order

  • Routine CTA, MRA, or DSA shows stenoses and raises a specific diagnostic question requiring vessel wall characterization.
  • Evaluate recurrent or otherwise unexplained (cryptogenic) ischemic stroke when an intracranial vascular cause is suspected.
  • Differentiate among intracranial atherosclerosis, CNS vasculitis, intracranial dissection, RCVS, and other intracranial vasculopathies.

Guide for Ordering Indications

Review the clinical indications and guidance on when to order this examination.

View indications and when to order →

Ordering Instructions

Penn Medicine Ordering

1MR Head Vessel Wall Vasculopathy With and Without IV Contrast
2MR Head Angio Vessel Wall Vasculopathy Without IV Contrast

Must order both MRI & MRA exams, which includes VWI, DWI, FLAIR, T2-weighted imaging, and SWI.

Ordering from Outside Penn Medicine

Order:

MR Head With and Without IV Contrast

MR Head Angio Without IV Contrast

In the comments/order indication, write:

“Vessel Wall MR Imaging for Vasculopathy”

Available sites

HUP/Pavilion (3T and 1.5T), PMC (3T), PCAM (3T), Radnor (3T), and PAH (1.5T).

Important notes

  • This is an advanced problem-solving examination, not a screening study.
  • For vasculitis work-ups, recommend starting with only a Brain VWI examination. A combined Brain and Neck VWI Vasculitis examination is lengthy and prone to motion, which may result in a nondiagnostic examination. A shorter limited protocol may be available for selected patients. Consult Neuroradiology.
BRAIN VWI Subarachnoid Hemorrhage Brain vessel wall MRI/MRA
Clinical question

Is there an occult vascular source for angiogram-negative atraumatic subarachnoid hemorrhage?

When to order

  • Angiogram-negative atraumatic SAH after CTA and DSA are negative.
  • As an adjunct to, and after, the recommended diagnostic work-up.
  • Evaluate for a blister or perforator aneurysm, dissecting aneurysm, occult AVF/AVM, or a culprit lesion when multiple aneurysms are present.

Guide for Ordering Indications

Review supporting guidance for evaluation of angiogram-negative SAH.

AHA/ASA guideline →
Diagnostic algorithm →

Ordering Instructions

Penn Medicine Ordering

1MR Head Vessel Wall (SAH) With and Without IV Contrast
2MR Head Angio Vessel Wall (SAH) Without IV Contrast

Must order both MRI & MRA exams, which includes VWI, DWI, FLAIR, T2-weighted imaging, and SWI.

Ordering from Outside Penn Medicine

Order:

MR Head With and Without IV Contrast

MR Head Angio Without IV Contrast

In the comments/order indication, write:

“Vessel Wall MR Imaging for Subarachnoid Hemorrhage”

Available sites

HUP/Pavilion (3T and 1.5T), PMC (3T), PCAM (3T), Radnor (3T), and PAH (1.5T).

Important notes

  • Optional: MR Cervical Spine With and Without IV Contrast may be ordered for posterior fossa SAH to evaluate for cervicomedullary AVF/AVMs. This adds an approximately 30-minute MR slot.
  • DSA remains the gold standard for AVF/AVM. MR Angiogram Neck evaluates the cervical carotid and vertebral arteries and is the incorrect order for this indication.
NECK VWI Arterial Dissection Cervical carotid or vertebral artery
Clinical question

Is there a cervical carotid or vertebral artery dissection?

When to order

  • Suspected cervical carotid or vertebral artery dissection.
  • Routine CTA or MRA neck raises a specific diagnostic question requiring vessel wall characterization.
  • Clarify equivocal luminal abnormalities and differentiate arterial dissection from other vasculopathies.
  • Due to wrap artifact from the shoulders, this examination cannot reliably assess vertebral artery origin dissections.

Guide for Ordering Indications

Order when a CTA/MRA questioned an arterial dissection in the neck.

Ordering Instructions

Penn Medicine Ordering

1MR Neck Angio Vessel Wall (Dissection) With and Without IV Contrast

Ordering from Outside Penn Medicine

Order:

MR Neck Angio With and Without IV Contrast

In the comments/order indication, write:

“Vessel Wall MRA Imaging for Dissection”

Available sites

HUP/Pavilion (3T and 1.5T), PMC (3T), PCAM (3T), Radnor (3T), and PAH (1.5T).

Important notes

  • This is an advanced problem-solving examination, not a screening study.
  • In the order comments, specify the artery (carotid versus vertebral) and segment (e.g., before or after the level of carotid bifurcation; skull base; craniocervical junction) of concern.
NECK VWI Carotid Artery Plaque Plaque characterization and carotid web
Clinical question

Could carotid plaque or a carotid web be responsible for the patient’s ischemic event?

When to order

  • Routine CTA or MRA neck has been performed and raised a specific question requiring characterization of non-calcified tissue in the carotid artery.
  • Concern for vulnerable carotid plaque, including intraplaque hemorrhage, vs carotid web vs arterial dissection in the carotid artery.

Guide for Ordering Indications

Use when a CTA or MRA questions culprit non-stenotic carotid plaque, carotid web or carotid artery dissection.

Ordering Instructions

Penn Medicine Ordering

1MR Neck Angio Vessel Wall (Plaque) With and Without IV Contrast

Ordering from Outside Penn Medicine

Order:

MR Neck Angio With and Without IV Contrast

In the comments/order indication, write:

“Vessel Wall MRA Imaging for Carotid Plaque”

Available sites

HUP/Pavilion (3T and 1.5T), PMC (3T), PCAM (3T), Radnor (3T), and PAH (1.5T).

Important notes

  • This is an advanced problem-solving examination, not a screening study, and is intended for targeted carotid plaque or carotid web characterization after a routine CTA or MRA neck.
NECK VWI Vasculitis Extracranial carotid or vertebral arteries
Clinical question

Is there inflammatory disease involving the extracranial carotid or vertebral arteries?

When to order

  • Concern for carotid or vertebral artery vasculitis.
  • Concern for TIPIC syndrome (carotidynia).
  • Routine CTA or MRA neck has been performed and raised a specific question.

Guide for Ordering Indications

Use when CTA or MRA questions extracranial arterial vessel wall inflammation.

Ordering Instructions

Penn Medicine Ordering

1MR Neck Angio Vessel Wall (Vasculitis) With and Without IV Contrast

Ordering from Outside Penn Medicine

Order:

MR Neck Angio With and Without IV Contrast

In the comments/order indication, write:

“Vessel Wall MRA Imaging for Vasculitis”

Available sites

HUP/Pavilion (3T and 1.5T), PMC (3T), PCAM (3T), Radnor (3T), and PAH (1.5T).

Important notes

  • This is an advanced problem-solving examination, not a screening study. Please do not order Brain VWI and Neck VWI Vasculitis together during the initial evaluation, as the combined examination length may lead to motion. Discuss with neuroradiology; a shorter limited protocol may be available for selected patients.
GCA VWI Giant Cell Arteritis Temporal and occipital arteries of the scalp
Clinical question

Are there imaging findings of giant cell arteritis involving the temporal or occipital arteries in a patient over 50 years of age?

When to order

  • Suspected giant cell arteritis. Evaluate inflammation of the temporal or occipital arteries, including in suspected relapse.
  • Negative or equivocal temporal artery biopsy despite persistent clinical suspicion.
  • Appropriate for outpatient evaluation in clinically stable patients.

Guide for Ordering Indications

Review patient selection, exclusions, and guidance on when to order GCA VWI/MRA.

View indications and when to order → 2021 American College of Rheumatology Guidelines (see p. 1353) →

Ordering Instructions

Penn Medicine Ordering

1MR Head Angio Giant Cell Arteritis With and Without IV Contrast

Ordering from Outside Penn Medicine

Order:

MR Head Angio With and Without IV Contrast

In the comments/order indication, write:

“Vessel Wall MR Imaging for Giant Cell Arteritis”

Available sites

HUP/Pavilion, PMC, PCAM, and Radnor.GCA VWI/MRA is performed only on 3T scanners.

Important notes

  • GCA VWI must be performed on a 3T scanner to achieve the required spatial resolution. Patients with a contraindication to 3T cannot undergo this examination.
  • To promote resource stewardship, ordering of a GCA VWI exam concurrently with a planned/scheduled temporal artery biopsy is not recommended.
  • If a temporal artery biopsy is performed, await the biopsy results before ordering GCA VWI.
  • The 2021 American College of Rheumatology guidelines conditionally recommend temporal artery biopsy over MR for establishing a definitive diagnosis of GCA (see p. 1353).
  • MR Brain/Rapid Stroke may be ordered if there is concern for stroke. Routine MR Orbits may be ordered if visual deficits are present.