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), PAH (1.5T-Brain), PCAM (3T), Radnor (3T)

  • Indication:

    Vasculopathy Differentiation (ddx Atherosclerosis, Vasculitis, Intracranial Dissection, RCVS...etc)

    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 diagnostic work-up Class 1 Recommendations from 2023 AHA/ASA Guidelines (page e11, #5 and 6) (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.

    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

    Order (1 exam):

    MR Neck Angio Vessel Wall (Plaque) WWO

  • Indication: Concern for carotid or vertebral artery vasculitis, TIPIC (carotidynia)

    Order (1 exam):

    MR Neck Angio Vessel Wall (Vasculitis) WWO

  • Indication: Evaluate for temporal arteritis (temporal and occipital arteries in the scalp only)

    Order (1 exam):

    MR Head Angio Giant Cell Arteritis WWO

    Notes:

    MR Brain (routine) or MR Brain Rapid Stroke can be ordered if concern for stroke.

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

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)