This document discusses cerebral venous thrombosis, including the major dural sinuses and cortical veins that can be affected. CT and MRI are important imaging modalities for diagnosis. CT can detect thrombi directly and identify signs of venous infarction. MRI and MR venography can identify thrombi by their abnormal signal and absence of flow void, as well as demonstrate venous infarction and edema. Common etiologies of cerebral venous thrombosis include hypercoagulability states, infection, trauma, and low flow states. Clinical manifestations vary but can include increased intracranial pressure symptoms, stroke symptoms, and seizures.

1. Cerebral Venous Thrombosis
Dr.Aftab Qadir

3. 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.

9. 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.

10. 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

11. 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

12. 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

14. MR Signal Intensity of Aging Blood

15. 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

16. 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

17. 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

18. Pathogenesis
• Dural sinus thrombosis leads to venous
congestion, venous infarction ,brain
edema and heamorrhage

19. Clinical Manifestations
Symptoms of increased Intracranial pressure
• Headache, nausea, vomiting, visual blurring
Stroke symptoms
• Dysphasia, cranial nerve palsy, seizures
Others
• Drowsiness, confusion, Fever

20. 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

21. • 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

22. DENSE CLOT SIGN

27. 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.

30. 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.

35. Hemorrhagic venous infarct in Labbe territory

37. CT-venography demonstrating thrombosis in many
sinuses.

38. Transverse MIP image of a Phase-Contrast angiography.
The right transverse sinus and jugular vein have no signal due to
thrombosis.

39. Acute thrombus in a 35-year-old woman with a severe headache
for 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).

40. DSA

41. 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

44. Pseudodelta sign

45. Normal transverse sinus (LT) Thrombosed transverse sinus(RT).

46. Wrong bolus timing

47. Hematoma simulating venous thrombosis

49. Transverse sinus flow gap. (a) Coronal image from TOF MR venography
shows 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 enhancement
indicative of normal flow in the medial part of the left transverse sinus (arrow).

52. Interactive SessionInteractive Session

58. Thank You