KEY FACTS Terminology Rapidly enlarging malignant astrocytic tumor characterized by necrosis and neovascularity Most common of all primary intracranial neoplasms Imaging Best imaging clue: Thick, irregularly enhancing rind of neoplastic tissue surrounding necrotic core Heterogeneous, hyperintense mass with adjacent tumor…
KEY FACTS Terminology Pilocytic astrocytoma (PA): Well-circumscribed, slow-growing tumor, often with cyst and mural nodule Imaging Cystic cerebellar mass with enhancing mural nodule Arises from cerebellar hemisphere and compresses 4th ventricle Enlarged optic nerve/chiasm/tract with variable enhancement Cerebellum (60%) >…
KEY FACTS Terminology Diffusely infiltrating malignant astrocytoma with anaplasia, marked proliferative potential Imaging Infiltrating mass that predominately involves white matter with variable enhancement T2 heterogeneously hyperintense Neoplastic cells almost always found beyond areas of abnormal signal intensity May involve and…
KEY FACTS Terminology Well-differentiated but infiltrating neoplasm, slow growth pattern Primary brain tumor of astrocytic origin with intrinsic tendency for malignant progression, degeneration into anaplastic astrocytoma (AA) Imaging Focal or diffuse nonenhancing white matter mass T2 homogeneously hyperintense mass May…
Introduction The most widely accepted classification of brain neoplasms is sponsored by the World Health Organization (WHO). A working group of world-renowned neuropathologists periodically convenes for a consensus conference on brain tumor classification and grading. The results are then published.…
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%…
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…
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…
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…
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…