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.
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
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
8.
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
10.
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
12.
13.
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
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
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
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.
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
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