KEY FACTS Terminology Cavernous sinus (CS) Blood clot in CS Imaging CT Bone CT – Look for sinus infection, erosive changes CECT – Nonenhancing filling defects (clot) inside enhancing dural walls of cavernous sinus (CS) – CS margins convex (not…
KEY FACTS Imaging General features Empty-delta sign on CECT, T1WI C+ MR CT Hyperdense sinus on NECT (usually > 70 Hounsfield units) ± hyperdense cortical veins (cord sign) CTV: Filling defect (thrombus) in dural sinus MR Hypointense thrombus “blooms” on…
KEY FACTS Terminology Rare (1-3%) disorder most commonly occurring as complication of cerebral revascularization Other etiologies less common – Status epilepticus – MELAS Major increase in ipsilateral cerebral blood flow (CBF) well above normal metabolic demands Imaging Ipsilateral gyral swelling,…
KEY FACTS Terminology Small, deep cerebral infarcts located in basal ganglia and thalamus, pons, or cerebral white matter (WM), ≤ 15 mm Imaging Commonly deep gray nuclei, especially putamen, thalamus, caudate nuclei; internal capsule, pons Other locations include deep and…
KEY FACTS Terminology Acute stroke related to fat emboli Imaging Acute ischemia with appropriate clinical history Long bone or pelvic fractures, cardiac surgery, joint replacement surgery Often mimics thromboembolic stroke Commonly affects both gray and white matter May affect deep…
KEY FACTS Terminology Infarcts in multiple arterial distributions from embolic source, often cardiac origin Imaging Best imaging clue: DWI restriction in multiple vascular distributions NECT: Multiple regions of low attenuation, loss of gray-white differentiation T2/FLAIR: Multiple supratentorial and infratentorial regions…
KEY FACTS Imaging Volume loss with gliosis along affected margins Classic: Wedge-shaped area of encephalomalacia Territorial infarction Involves brain supplied by major cerebral artery Watershed infarction Involves brain between main vascular territories Lacunar infarction(s) Most common in basal ganglia/thalami, deep…
KEY FACTS Terminology Subacute infarction ~ 2-14 days following initial ischemic event Imaging Best diagnostic clue: Gyral edema and enhancement within basal ganglia and cortex Typically wedge-shaped abnormality involving gray and white matter within vascular distribution Hemorrhagic transformation of initially…
KEY FACTS Terminology Interrupted blood flow to brain resulting in cerebral ischemia/infarction with variable neurologic deficit Imaging Major artery (territorial) infarct Generally wedge-shaped; both GM and WM involved Embolic infarcts Often focal/small, at GM-WM interface NECT Hyperdense vessel = clot…
KEY FACTS Terminology Acute alteration of neurologic function due to loss of vascular integrity Imaging Best imaging MR with diffusion, perfusion, MRA MRV if MRA negative and DWI positive Can do emergent “limited” MR (FLAIR, DWI, SWI) Imaging findings CT…