University of Pennsylvania

Penn Vessel Wall Imaging

Center of Excellence

Clinical Care Education Research

Jae W. Song, MD, MS

Founding Director

How to Interpret VWI

Select an examination below for the protocol, principal interpretation tasks, practical pearls, and available teaching resources.

BRAIN VWI Stroke & Vasculopathy Intracranial vessel wall MRI/MRA
Interpretation task

Characterize the distribution and morphology of intracranial vessel wall thickening and enhancement, and integrate the findings with the luminal abnormality and infarct pattern.

Protocol

  • Pre- and postcontrast vessel wall imaging
  • TOF MRA
  • DWI, SWI, high-resolution T2-weighted TSE, and FLAIR
  • Limited option: pre/post VWI, T2-weighted imaging, and SWI

Interpretation pearls

  • Compare pre- and postcontrast VWI directly before assigning enhancement.
  • Use high-resolution T2-weighted imaging and VWI together to assess eccentric versus concentric wall thickening.
  • Correlate the wall abnormality with the TOF MRA and the vascular territory of ischemia.
  • Avoid interpreting enhancement in isolation; morphology, distribution, and clinical context matter.

Brain VWI/MRA Interpretation Resources

Start with the fundamentals video for a stepwise approach, then use the interpretation summary as a point-of-care reference.

ASNR 2021: VWI Interpretation Fundamentals

Open the interpretation summary →
BRAIN VWI Subarachnoid Hemorrhage Angiogram-negative SAH evaluation
Interpretation task

Identify a potential occult culprit lesion and determine whether the vessel wall and hemorrhage pattern localize to a plausible source.

Protocol

  • Pre- and postcontrast vessel wall imaging
  • TOF MRA
  • DWI, SWI or 3D T2*, high-resolution T2-weighted TSE, and FLAIR
  • Optional limited cervical spine: sagittal pre/post T1-weighted and sagittal T2-weighted imaging

Interpretation pearls

  • Use pre/post VWI to assess focal wall enhancement, wall irregularity, enhancing clot, or a subtle dissecting lesion.
  • Use SWI or T2* imaging to identify the epicenter and distribution of hemorrhage.
  • When a limited cervical spine examination is obtained, evaluate for serpiginous flow voids and cord edema suggesting a cervicomedullary AVF/AVM.
  • VWI is an adjunct; DSA remains the reference standard for AVF/AVM evaluation.

Interpretation resource

Use the SAH interpretation guide for a structured approach to angiogram-negative subarachnoid hemorrhage.

Open the VWI-SAH interpretation guide →
NECK VWI Neck VWI Options Dissection, carotid plaque, and vasculitis
Interpretation task

Apply the indication-specific sequence to characterize mural hematoma, intraplaque hemorrhage, or inflammatory wall edema and enhancement.

Core protocol

  • Pre- and postcontrast coronal vessel wall imaging
  • Postcontrast MRA
  • Indication-specific sequence selected according to the clinical question

Indication-specific approach

  • Dissection: axial precontrast T1-weighted TSE with fat suppression for mural hematoma.
  • Carotid plaque: coronal precontrast T1-weighted MPRAGE with fat suppression for intraplaque hemorrhage.
  • Vasculitis: axial STIR for vessel wall edema, interpreted with postcontrast wall enhancement.
  • Correlate the wall finding with the luminal abnormality and the precise artery and segment identified in the order.

Interpretation resource

Neck VWI interpretation guide is in development.

GCA VWI Giant Cell Arteritis Temporal and occipital arteries of the scalp
Interpretation task

Evaluate the temporal and occipital arteries for abnormal wall enhancement while confirming that the enhancing structure corresponds to an artery on the TOF MRA.

Protocol

  • TOF MRA of the scalp arteries
  • Postcontrast high-resolution vessel wall imaging
  • Performed on a 3T scanner for the required spatial resolution

Interpretation pearls

  • Evaluate the superficial temporal and occipital arterial territories systematically and bilaterally.
  • Confirm the vessel on TOF MRA before attributing enhancement to an artery rather than an adjacent vein.
  • Assess the distribution, conspicuity, and symmetry of arterial wall enhancement.
  • Interpret imaging findings in the context of symptoms, inflammatory markers, treatment timing, and biopsy results when available.

Interpretation resource

Use the scalp VWI guide for a structured approach to temporal and occipital artery assessment.

See also Teaching Case #5 in Penn VWI Teams Group.

Open the GCA interpretation guide →