Vessel Wall MR Imaging

Vessel Wall MR Imaging

Vessel wall MRI (VWI) is an advanced imaging technique and service available for our valued Penn patients & clinicians. Resources for this service include years of meticulously optimized cerebrovascular imaging pulse sequences/protocols, trained cerebrovascular MR technologists, and the invaluable interpretive expertise of the Penn Neuroradiologists.

Ordering & Protocoling

Please assess need & timing.

Can this request be an outpatient VWI & can patient tolerate ~60min MRI/MRA exams? 

Available sites: HUP/Pav (3T), PMC (3T), PCAM (3T), Radnor (3T), PAH (1.5T)

  • Indication:

    For vasculopathy differentiation (ddx Atherosclerosis, Vasculitis, Intracranial Dissection, RCVS, CNS vasculitis, recurrent cryptogenic strokes...etc).

    This advanced exam can be considered if routine CTA head, MRI or MRA head or DSA was performed and raised a question; this is not a screening exam.

    Order 2 exams (MRI +MRA):

    MR Head Vessel Wall Vasculopathy WWO**

    MR Head Angio Vessel Wall Vasculopathy WO

    **Includes VWI & DWI, SWI, FLAIR, T2w

    Note: Limited (shorter) VWI option available with only pre/post VWI, SWI, T2w sequences. Speak to neuroradiologist.

  • Indication:

    Angiogram-negative (CTA/DSA negative) atraumatic SAH.

    VWI can be performed as adjunct to & after recommended work-up. See 2023 AHA/ASA Guidelines & (algorithm), & ACR Appropriateness Criteria).

    Evaluate for blister/perforator aneurysms, dissecting aneurysm, occult AVF/AVM, or multiple aneurysms.

    Order 2 exams (MRI + MRA):

    MR Head Vessel Wall (SAH) WWO**

    MR Head Angio Vessel Wall (SAH) WO

    **Includes VWI & DWI, SWI, FLAIR, T2w

    Optional:

    MR Cervical Spine WWO (includes sag T1 pre/post, sag T2 only) can be ordered if posterior fossa SAH. This is to screen for a cervicomedullary AVF/AVMs.†* This is an additional 30-min MR slot.

    †DSA is gold standard for AVF/AVM.

    *MRA neck evaluates cervical carotid & vertebral artery lumen (eg stenosis). MRA neck is the incorrect order for this indication.

  • Indication: Concern for cervical carotid or vertebral artery dissection. This advanced exam can be considered if routine CTA or MRA neck was performed and raised a question; this is not a screening exam.

    Order (1 exam):

    MR Neck Angio Vessel Wall (Dissection) WWO

    *In comments, please write which arteries and segments are of concern (carotid vs vertebral; origin, mid, skull-base/craniocervical)

  • Indication: Concern for unstable carotid artery plaque (intraplaque hemorrhage), carotid web. This advanced exam can be considered if routine CTA or MRA neck was performed and raised a question; this is not a screening exam.

    Order (1 exam):

    MR Neck Angio Vessel Wall (Plaque) WWO

  • Indication: Concern for carotid or vertebral artery vasculitis, TIPIC (carotidynia). This advanced exam can be considered if routine CTA or MRA neck was performed and raised a question; this is not a screening exam.

    Order (1 exam):

    MR Neck Angio Vessel Wall (Vasculitis) WWO

  • Indication: Evaluate for temporal arteritis (temporal and occipital arteries in the scalp only). TOF MRA will screen for intracranial vasculopathy.

    Order (1 exam):

    MR Head Angio Giant Cell Arteritis WWO

    Notes:

    *Should be performed on 3 Tesla due to need for very high spatial resolution.

    *MR Brain/Rapid Stroke can be ordered if concern for stroke.

    *MR Orbits (routine) can be ordered if visual deficits present.

    *Temporal artery biopsy is the recommended diagnostic standard by the 2021 Am Coll Rheum Guidelines.

How to Interpret VWI

ASNR 2021: Basics of VWI (14min)

  • Protocol: Pre/Post VWI, TOF MRA DWI, SWI, T2w TSE, FLAIR; Also, option to run Limited VWI exam with only VWI/T2/SWI, as indicated.

    Pearls: Use Pre/Post VWI and hi-res T2w for ecc/concentric vessel wall thickening/enhancement

    Guide: ASNR 2021 How-to-Interpret Video (14min) & summary (link)

  • Protocol: Pre/Post VWI, TOF MRA, DWI, SWI/3DT2STAR, T2w TSE, FLAIR

    Limited C-spine: Pre/Post sag T1w, sag T2

    Pearls: Use Pre/Post VWI (enhancing clot, wall irregularity) & SWI (epicenter of hemorrhage).

    Limited C-spine (optional): look for dAVF/AVM (serpiginous flow voids, cord edema)

    Guide: VWI-SAH Interpretation (link)

  • Protocol: Pre/Post cor VWI, Dynamic post MRA

    Options include:

    Dissection: Ax Pre T1 TSE FS (mural hematoma)

    Carotid Plaque: Cor pre T1 MPRAGE FS (intraplaque hemorrhage)

    Vasculitis: Ax STIR (wall edema)

    Guide: Neck VWI Interpretation Tip Sheet (WIP)

  • MRA GCA (Scalp Imaging):

    Protocol: TOF MRA, post VWI

    Pearls: Evaluate temporal and occipital arteries. Confirm artery on TOF MRA (not vein).

    Guide: GCA Interpretation (link)