Dural venous sinus thrombosis for Radiology & Imaging

1. Dural Venous Sinus
Thrombosis
Dr. Manmohan Bir Shrestha
FOR RADIOLOGY

2. Dural venous sinuses
 are venous channels located intracranially between the two layers of dura
mater.
 run alone, not parallel to arteries
 are valveless, allowing for bidirectional blood flow in intracranial veins
 it is also important to note that the draining territories of intracranial veins are
different from those of major cerebral arteries.
 form the major drainage pathways from the brain, predominantly to
the internal jugular veins.

3. Can be classified as -
Paired
Transverse sinus
Sigmoid sinus
Superior petrosal sinus
Inferiror petrosal sinus
Cavernous sinus
Sphenoparietal sinus
Basilar venous plexus
Unpaired
Superior sagittal sinus
inferior sagittal sinus
Straight sinus
Occipital sinus
Intercavernous sinus

5. Venous angle & Internal Cerebral veins
Septal vein – runs on the medial surface of frontal
horn
Thalamostriate vein – runs in the floor of the lateral
ventricle
Venous angle
In the lateral view, the junction of septal & thalamostriate vein
forms the origin of internal cerebral vein & is known as the
“Venous Angle”
Internal cerebral vein commence just behind the
foramen of monro
Near the splenium, 2 internal cerebral vein unites &
continues as great cerebral vein of Galen

6. Venous Angle

7. Basal/Rosenthal Vein
Deep middle cerebral vein drains the insula & is
joined by anterior cerebral & striate veins to form the
basal vein
Basal vein arises anteriorly above the sella & passes
around the midbrain to enter the back end of the
Internal Cerebral Vein

9. Straight Sinus
 Vein of Galen curves upward & backward behind the
splenium of the corpus callosum
 Here, it joins inferior sagittal sinus to form the straight sinus
which passes downward in the apex of the tentorium to the
torcular herophili
 Straight sinus usually drains into the left transverse sinus
 Superior sagittal sinus usually drains into the right transverse
sinus

11. The vein of Trolard & Labbe
The vein of Trolard/ Superior anastomotic vein
Large vein which passes upward & backward over the cerebral hemisphere
to enter the superior sagittal sinus in the parietal region.
Connects superficial middle cerebral vein to superior sagittal sinus
The vein of Labbe/ Inferior anastomotic vein
Large vein which passes horizontally across the temporal region to enter
the transverse sinus.
Connects superficial middle cerebral vein to transverse sinus
T – Trolard – Top one
L- Labbe – Lower one

14. Torcular Herophili / Torcula
 The confluence of sinuses
Superior sagittal sinus
Straight sinus
Occipital sinus
Transverse sinuses
 The anatomy is highly variable
 type 1: superior sagittal sinus drains into one lateral sinus and
the straight sinus into the other, with no connection between
the two
 type 2: superior sagittal sinuses and the straight sinus fork,
and the forks from both sinuses join to form the lateral
sinuses
 type 3: a true confluence of sinuses

15. Cavernous sinus
Located on either side of pituitary fossa & body of
the sphenoid bone
It spans from the apex of the orbit to the apex of the
petrous temporal bone
Structures passing through are –
Internal Carotid Artery
Oculomotor nerve
Trochlear nerve
Abducens nerve
Ophthalmic nerve
Maxillary nerve

16. Cavernous sinus
Receives blood from
Superior & inferior ophthalmic vein
Intercavernous sinus
Sphenoparietal sinus
Superficial middle cerebral vein
Occasionally central retinal vein
Drains into
Superior petrosal sinus
Inferior petrosal sinus
Basilar venous plexus

17. Dural Venous Sinus
Thrombosis

18. Dural Venous Sinus Thrombosis
Thrombotic occlusion of dural venous sinuses
Often coexist with cortical vein thrombosis
Can occur in isolation of single venous sinus
or in combined with one another
Common occurrence-
Superior sagittal sinus
Straight sinus
Transverse sinus
Sigmoid sinus
Cavernous sinus

19. Age
Any age
Gender
Female>Male

20. Predisposing factors
Identified in most cases
Hormonal
Oral contraceptive pill
Pregnancy, puerperium, steroids
Hematological - coagulopathy
Genetics –
Protein S deficiency
Prothrombin gene mutation
Resistance to activated protein C

21. cont.......
Local factors
Skull trauma
Compressing mass
Infection – specially mastoid sinus
Systemic illness
Dehydration
Sepsis
Malignancy
Connective tissue disorders
idiopathic

22. Clinical features
Headache
Nausea
Vomiting
Seizures
Altered consciousness
Altered vision
Cavernous sinus thrombosis can result in
Exophthalmos
Chemosis ( swelling of conjunctiva)
Oedema of the eyelids
Oculomotor palsies.
Papilloedema.

23. Pathology
Thrombus in dural venous sinus
Clot propagates into cortical veins
Venous drainage obstructed, venous pressure elevated
Blood-brain barrier breakdown with vasogenic edema,
hemorrhage
Venous infarct with cytotoxic edema

24. Imaging modalities
NECT
CECT
CT Venogram
MRI
MR Venogram

25. NECT
Findings can be subtle when no venous
hemorrhage or infarct
Cerebral edema
Venous hemorrhage
Venous infarct
Hyperdense vein sign
>65 HU
Compare to carotid arteries

26. Cont…
Cord sign
Cordlike hyper attenuation within a dural
venous sinus
A false positive cord sign may also be seen in
the setting of generalized cerebral edema when
it is actually the brain which is of reduced
density rather than the sinus being
hyperdense.

27. Cord sign

28. CECT & CT Venogram
Filling defect in dural sinus
Shaggy enlarged/irregular collateral venous
channels
Empty delta sign
Enhancing dura surrounds non-enhancing
thrombus
In coronal/axial section in superior sagittal sinus

29. Empty delta sign
Delta (uppercase Δ, lowercase δ)
Is the 4th letter of Greek word
Delta sign resembles a triangle

30. MRI
T1WI
Acute thrombus – isointense with brain
Subacute thrombus – hyperintense
Chronic thrombus - isointense
T2WI
Acute thrombus –hypointense ( can mimic normal flow void)
Subacute thrombus – hyperintense
Chronic thrombus – hyperintense
 T2*GRE
Hypointense thrombus usually blooms

31. 2D TOF or Contrast MRV
Absence of flow in occluded sinus in 2D TOF
MRV
Contrast enhanced MRV shows thrombus &
collaterals much better
Flow gaps on MIPs must be reviewed on
source images to exclude hypoplastic sinus
variants, particularly for transverse & sigmoid
sinus

32. Case of –
young adult female
with sudden onset severe headache and left
sided weakness
Cases

36. After 9 hours
Right sided venous hemorrhage
with multilobulated appearance

37. Case of
30 yrs. old female.
Postpartum severe headache and disturbed
conscious level.

41. SWI

42. Treatment
In-patient heparin followed by out-patient warfarin
Anticoagulation is usually required even in the
setting of venous hemorrhage.
Interventional management includes microcatheter
thrombolysis or thromboplasty
*** Associated abnormalities – Dural AV fistula

43. Differential diagnosis
Dural sinus hypoplasia-aplasia
31% flow gaps in nondominant sinus
Right transverse sinus dominant – 59 %
Left transverse sinus dominant – 25%
Concomitant – 16 %
If the sinus is small or absent, then the
ipsilateral sigmoid sinus and jugular
fossa should also be small

44. Giant arachnoid granulations
Round/ovoid filling defect
CSF signal density/signal intensity
By imaging – most common location is
transverse sinus
On histopathology – superior sagittal sinus is
most common location

45. Presenting case