Imaging in Neurology

Capillary Telangiectasia

KEY FACTS Terminology Brain capillary telangiectasia (BCT) Cluster of enlarged, dilated capillaries interspersed with normal brain parenchyma Imaging General features Common sites: Pons, cerebellum, spinal cord Usually < 1 cm CT Usually normal MR T1WI usually normal T2WI – 50%…

Cavernous Malformation

KEY FACTS Terminology Cavernous malformation (CM) Benign vascular hamartoma Contains masses of closely apposed immature blood vessels (“caverns”), no neural tissue Intralesional hemorrhages of different ages Imaging General: Locules of variable size with blood at different stages of evolution Variable…

Developmental Venous Anomaly

KEY FACTS Terminology Congenital cerebral vascular malformation with mature venous elements May represent anatomic variant of otherwise normal venous drainage Imaging General features Umbrella-like collection of enlarged medullary (white matter) veins (“Medusa head”) At angle of ventricle Numerous linear or…

Dural Arteriovenous Fistula

KEY FACTS Imaging Location: Dural sinus wall Posterior fossa >> supratentorial Can involve any dural sinus (transverse/straight sinus most common) NECT Usually normal; ICH if outlet vein thrombosed or flow-related aneurysm, venous pouch ruptures Bone CT Dilated transosseous calvarial vascular…

Arteriovenous Malformation

KEY FACTS Terminology Pial vascular malformation of brain Artery → vein shunting, no intervening capillary bed Imaging General features Supratentorial (85%), posterior fossa (15%) CT/CTA Iso-/hyperdense serpentine vessels ± Ca++ Arterial feeders, nidus, draining veins enhance MR “Bag of worms”/tangle…

Vascular Malformations Overview

General Considerations Cerebrovascular malformations (CVMs) of the brain are a heterogeneous group of disorders that represent morphogenetic errors affecting arteries, capillaries, veins, or various combinations of vessels. The presentation, natural history, and management approaches to CVMs depend on their type,…

Atherosclerotic Vascular Disease (ASVD) Fusiform Aneurysm

KEY FACTS Terminology Atherosclerotic vascular disease fusiform aneurysm (ASVD FA) ASVD → abnormal dilation, tortuosity of intracranial arteries Aneurysms with separate inflow, outflow ostia Imaging Exaggerated arterial ectasia(s) + focal fusiform/saccular enlargement Long segment irregular fusiform or ovoid arterial dilatation…

Vertebrobasilar Dolichoectasia

KEY FACTS Terminology Extensive ectatic, elongated vertebrobasilar artery (VBA) Usually associated with decreased blood flow velocity Imaging General findings Irregular, elongated, tortuous VBA Usually 6-12 mm, can be giant (> 2.5 cm) Focal arterial dilatation = fusiform aneurysm CT Hyperdense…

Saccular Aneurysm

KEY FACTS Terminology Intracranial saccular aneurysm (SA) Outpouching affecting only part of arterial circumference Lacks internal elastic lamina ± tunica media Imaging Round/lobulated arterial outpouching Usually arises from bifurcations of circle of Willis (COW), supraclinoid internal carotid and middle cerebral…

Convexal Subarachnoid Hemorrhage (cSAH)

KEY FACTS Terminology Unique type of subarachnoid hemorrhage (SAH) Localized to sulci over top (“convexity”) of brain Imaging NECT: Hyperdensity in 1 or several adjacent dorsolateral convexity sulci Spares basal, perimesencephalic cisterns MR Sulcal cerebrospinal fluid (CSF) replaced by isointense…