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Vascular Malformations: Brain
Alice Boyd Smith, MDChief, Neuroradiology
Department of Radiologic PathologyArmed Forces Institute of Pathology
Washington, DC &
Assistant Professor of Radiology & Radiological SciencesUniformed Services University of the Health Sciences
Nidus = Conglomeration of numerous AV shunts & dysplastic vessels
T2
Hereditary Hemorrhagic Telangiectasia
An angiodyplastic disorder with AD inheritance
>3 concurrent cerebral AVMS –Rare!
AVM• Dysregulated
angiogenesisÆcontinued vascular remodeling
• Peak age: 20-40 year old
• Risk of hemorrhage: 2-4%/year– ~50% present with
symptoms of hemorrhage
NECT
AVM Grading: Spetzler -Martin Scale
• Size– Small (<3cm) = 1– Medium (3-6 cm) = 2– Large (>6 cm) = 3
• Location– Noneloquent = 0– Eloquent = 1
• Venous drainage– Superficial = 0– Deep = 1
AVM Imaging: CT
• Variable Hemorrhage
• Calcification: 25-30%• Enhance post-
contrast• CTA: Enlarged
arteries & draining veins
CECT
AVM
Calcification Hemorrhage
NECT NECT
AVM Imaging: MRI
• Flow Voids: “Bag of worms”
• Variable hemorrhage– “Blooming” on T2* GRE
• T2: Increased signal Ægliosis
• Contrast: Strong enhancement
• MRA/MRV
T2FLAIR
AVM
Cerebrofacial Arteriovenous Metameric Syndromes
AVM Imaging: Conventional Angiography
• Best method of imaging
• Must image ICA, ECA & vertebral circulations– 27-32% of AVMs have
dual arterial supply
Orbit & Sinus: What are you looking for?
Alice Boyd Smith, Lt. Col., USAF MCChief, Neuroradiology
Department of Radiologic PathologyArmed Forces Institute of Pathology
Washington, DC &
Assistant Professor of Radiology & Radiological SciencesUniformed Services University of the Health Sciences
Bethesda, MD
Objectives
• Recognize imaging findings in orbits & paranasal sinuses that will change patient management.
• Be able to develop “checklist” for imaging findings within orbits & paranasal sinuses that decreases likelihood of overlooking pertinent associated findings.
Orbits & Sinuses
• Infection• Trauma• Neoplasm
Orbit: Infectious
• Pre - or post-septal• Most often secondary to
underlying paranasalsinusitis– Maxillary & ethmoid most
– Central venous drainage– Obstruction of venous outflow– Varix
• Small nidus
NECT
NECT
AVM: Treatment
• Embolization• Radiation: Stereotaxic
radiosurgery – Eloquent
• Surgery
Combination
Arteriovenous Fistulas
• Distinguished from AVMs by presence of direct, high flow fistula between artery & vein– Dural AVF (dAVF)– Cavernous carotid fistula (CCF)– Vein of Galen malformation
dAVF• Arteriovenous shunts within
dura• 10-15% of intracranial
vascular malformations• 2 types:
– Adult: Tiny vessels in wall of thrombosed dural venous sinus Æ typically middle aged & older patients
• Usually acquired - trauma– Infantile: Multiple high-flow AV-
shunts involving several thrombosed dural sinuses Fetal MRI
SSFSE
dAVF
SSFSE T1
T1
dAVF Grading: Cognard Classification
• Type I: In sinus wall, normal antegrade venous drainage
• Type II: In main sinus– A: Reflux into sinus– B: Reflux into cortical veins: 10-20% hemorrhage
• Type III: Direct cortical drainage– 40% hemorrhage
• Type IV: Direct cortical drainage + venous ectasia– 2/3 hemorrhage
• Type V: Spinal perimedullary venous drainage– Progressive myelopathy
dAVF Grading: Lalwani et al
Type I Type II Type III Type IV
dAVF
• Most common near skull base– Transverse sinus most
common• Hemorrhage incidence:
2-4% per year• Spontaneous closure
rare– Most are type I
dAVF Imaging: CT
• NECT: May be normal• CECT: May see tortuous dural feeders &