Indication:

Guide for When-to-Order VWI Brain Indications (tipsheet).

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

**Do not concurrently order VWI MRA Neck VWI Vasculitis for initial work-up (Both exams are often too long for patients to tolerate).

** This advanced VWI exam that can be considered if routine CTA/MRA/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 arteries (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.

*Do not concurrently order Brain VWI and Neck VWI for CNS vasculitis work-up; Exams are too long and patients are often unable to tolerate both exams.

Order (1 exam):

MR Neck Angio Vessel Wall (Vasculitis) WWO

Ordering Guidelines

Exclusion: GCA MRA must be performed on a 3T scanner to achieve the required spatial resolution. Patients with contraindications to 3T will not be able to undergo GCA MRA exams.

*Temporal artery biopsy (TAB) is the preferred and currently accepted diagnostic standard over MRA by the 2021 Am Coll Rheum Guidelines.

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:

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

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