Cerebral venous thrombosis
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Cerebral Venous Thrombosis Dr.Aftab Qadir
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Transcript of Cerebral venous thrombosis
Cerebral Venous Thrombosis
Dr.Aftab Qadir
Major dural sinuses: • Superior sagittal sinus, transverse, straight and sigmoid
sinuses.
Cortical veins:• Vein of Labbe, which drains the temporal lobe.• Vein of Trolard, which is the largest cortical vein that drains
into the superior sagittal sinus.
Deep veins: • Internal cerebral and thalamostriate veins.
Cavernous sinus.
CT scan of a 45-year-old woman with clinical suspicion of dural sinus thrombosis.Lateral (A), anteroposterior (B), caudocranial (C), and oblique sagittal (D) MIP of CTA data set after MMBE. The projections demonstrate normal appearance of the superior sagittal sinus (arrowheads), the transverse sinuses (arrows), the deep venous system, and the superficial cortical veins without any overlying bone structures.
Indications For CT and MRI in Acute stroke
Indications for CT in suspected stroke• Early diagnosis if possible• Differentiation between ishcemic and
heamorrhagic stroke • Exclusion of stroke mimics-tumors
Indication for MRI
• If CT is normal and clinical suspicion high• Assessment of diffusion and perfusion
mismatch• Detection of stroke in posterior fossa• Detection of underlying cause • Assessment of intra and extracranial vessels
by MR angiography• Exclusion of venous sinus thrombosis
Appearance of Blood on Scans
On CT• Acute –Higher attenuation than underlying
brain• Sub acute-Similar attenuation to brain• Chronic-Lower attenuation than underlying
brain
MR Signal Intensity of Aging Blood
WT FAT H2O MUSC LIG BONE
T1 B D I D D
T2 I B I D D
WW2--> water white on T2 weighted image
Venous sinus thrombosis
• < 2% of all strokes• Accounts for up to 50% of strokes during
pregnancy and puerperium• Important cause of stroke especially in
children and young adults• It is a difficult diagnosis because of its
nonspecific clinical presentation and subtle imaging findings
ETIOLOGY
• Spontaneous
Septic causes( especially in children)• Sinusitis, Otitis, Mastoiditis, Sub/epidural
empyema• Meningitis, encephalitis, Brain abscess, Face
and scalp cellulitis, septicemia
Trauma > Fracture through sinus wall,jugular vein catheriziation
Low flow states > CHF, Dehydration ,Shock
Hypercoagulability states
Pathogenesis
• Dural sinus thrombosis leads to venous congestion, venous infarction ,brain edema and heamorrhage
Clinical Manifestations
Symptoms of increased Intracranial pressure• Headache, nausea, vomiting, visual blurring
Stroke symptoms• Dysphasia, cranial nerve palsy, seizures
Others• Drowsiness, confusion, Fever
Imaging
• CT brain , CTV• MRI brain and MRV• Cerebral angiography
Look for• Direct signs of a thrombus• Infarction in a non-arterial location, especially if it is
bilateral and hemorrhagic• Cortical or peripheral lobar hemorrhage• Cortical edema
• Dense Clot sign on NECT• Cord sign• Empty delta sign on CECT• Replacement of flow void by abnormal
signal intensity on MRI• MRV absence of flow • Non filling of thrombosed veins on
Angiography• Venous infarction, edema
DENSE CLOT SIGN
ABSENCE OF NORMAL FLOW VOID ON MR
Patent cerebral veins usually will demonstrate low signal intensity due to flow void.
Flow voids are best seen on T2-weighted and FLAIR images.
A thrombus will manifest as absence of flow void.
VENOUS INFARCTION
Due to the high venous pressure hemorrhage is seen more frequently in venous infarction compared to arterial infarction.
Often bilateral and in the midline in an atypical location or in a non-arterial distribution.
Hemorrhagic venous infarct in Labbe territory
CT-venography demonstrating thrombosis in many sinuses.
Transverse MIP image of a Phase-Contrast angiography.The right transverse sinus and jugular vein have no signal due to
thrombosis.
Acute thrombus in a 35-year-old woman with a severe headachefor 5 days. Axial T2W MR image (a) and axial T1W MR image (b) show a thrombus in
the left sigmoid sinus (arrows). The signal in the thrombus, compared with that in the normal brain parenchyma, is hypointense in a and iso- to hyperintense in b. (c) Frontal MIP image from coronal TOF MR venography shows a lack of flow in the
distal portion of the left transverse sinus and the sigmoid sinus (arrows).
PITFALLS IN CT
Arachnoid granulations produce well-defined focal filling defects within the dural venous sinuses and measure 2–9 mm in diameter. They are isoattenuating (one-third) or hypoattenuating (two-thirds) relative to brain parenchyma
Arachnoid granulations
Normal transverse sinus (LT) Thrombosed transverse sinus(RT).
Wrong bolus timing
Hematoma simulating venous thrombosis
Transverse sinus flow gap. (a) Coronal image from TOF MR venographyshows an apparent interruption of flow in the medial part of the left transverse sinus (arrows).(b) Oblique MIP image from contrast-enhanced MR venography shows enhancementindicative of normal flow in the medial part of the left transverse sinus (arrow).
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