radiological appearance of cerebral venous thrombosis . lecture covers : - brief anatomy. - relevant clinical anatomy. - radiological imaging. - guidelines for management of CVT.

1. VENOUS SINUSES THROMBOSIS

2. • anatomy
• prevalnce
clinical presenation
• Radiological
examination

3. ANATOMY
•
Cerebral Venous Sinuses : “ large low-pressure veins within the folds of dura – between
fibrous dura and endosteum, except for the inferior sagittal and the straight sinuses
which are between two layers of fibrous dura

5. PREVELANCE
•
•
•
CVT is an uncommon and frequently unrecognized type of stroke that affects
approximately 5 people per million annually and accounts for 0.5% to 1% of all strokes.
CVT is more commonly seen in young individuals.
•
RISK FACTORS
Prothrombotic Conditions
•
Pregnancy and Puerperium
•
Oral Contraceptives
•
Cancer

6. PREVELANCE
•
in a retrospective study KAMC-Jeddah , 111 patients diagnosed as CVST were
identified from 1990 - 2010.
Age
mean Age is 29.5
17%
Adults
83%
children
Adult( F>M), pediatric(M>F)
Superior Saggital Sinus is most affected

7. CLINICAL PRESENTATIONS
•
headache
•
focal neurologic deficits
•
seizures
•
papilledema
•
decreased level of consciousness

8. DIAGNOSTIC IMAGING
•
Diagnostic imaging of CVT may be divided into 2 categories :
1. Noninvasive modalities
2. invasive modalities
The goal is to determine vascular and parenchymal changes associated
with this medical condition.

9. NON CONTRAST CT SCAN
•
The primary sign of acute CVT on a noncontrast CT is
hyperdensity of a cortical vein or dural sinus.
•
Acutely thrombosed cortical veins and dural sinuses appear as a
homogenous hyperdensity that fills the vein or sinus and are most
clearly visualized when CT slices are perpendicular to the dural sinus
or vein

10. NON CONTRAST CT SCAN
•
Thrombosis of the posterior portion of the superior sagittal sinus
may appear as a dense triangle, the dense or filled delta sign.

11. Noncontrast computed
tomography head scan
showed spontaneous
hyperdensity of right
transverse sinus.

12. CONTRAST-ENHANCED CT
•
may show enhancement of the dural lining of the sinus with a filling
defect within the vein or sinus.
•
the classic “empty delta” sign.

13. •
Contrast enhanced CT demonstrates
the reverse delta sign (or empty
triangle sign – lower image) which
can be seen in the superior sagittal
sinus from enhancement of the dural
leaves surrounding the comparatively
less dense thrombosed sinus.
•
Image Credit :
http://www.radiologytutorials.com/

14. MRI
•
The principal early signs of CVT on non–contrast-enhanced MRI are the combination
of absence of a flow void with alteration of signal intensity in the dural sinus.
•
a central isodense(hypodense) lesion in a venous sinus with surrounding
enhancement. This appearance is the MRI equivalent of the CT empty delta sign.
•
The secondary signs of MRI may show similar patterns to CT, including cerebral
swelling, edema, and/or hemorrhage

15. T2-weighted
magnetic resonance
image showing highintensity bland
venous infarct in
frontal lobe.
!

16. CT
VENOGRAPHY
•
CTV can provide a rapid and reliable modality for
detecting CVT.
!
•
CTV is much more useful in subacute or chronic
situations because of the varied density in thrombosed
sinus

17. Computed tomographic
venogram (axial) showing
extension of the cerebral
venous thrombosis down to
the jugular vein (black arrow).
R-ICA indicates right internal
carotid artery; L-ICA, left
internal carotid artery; R, right;
and L, left.
!

18. MRI
VENOGRAPHY
The most commonly used MRV techniques are time-of-flight (TOF) MRV and
contrast-enhanced magnetic resonance. Phase-contrast MRI is used less
frequently, because defining the velocity of the encoding parameter is both
difficult and operator-dependent.
The 2-dimensional TOF technique is the most commonly used method
currently for the diagnosis of CVT, because 2-dimensional TOF has
excellent sensitivity to slow flow compared with 3-dimensional TOF

19. Magnetic resonance
venography confirmed
thrombosis (black
arrows) of right
transverse and sigmoid
sinuses and jugular
vein.
!

20. Magnetic resonance venogram
showing thrombosis (black
arrows) of the superior sagittal
sinus and sigmoid sinuses. A, 2
days after symptom onset. B, 1
year follow-up after oral
anticoagulation therapy (OAC).
!

21. CT Scan + CTV
MRI + MRV
Visualization of the superficial and deep
Good visualization of major venous
venous systems
sinuses
+Good definition of brain parenchyma
Echoplanar T2 susceptibility-weighted
Overall accuracy 90% to 100%, depending
imaging combined with MRV are
on vein or sinus
considered the most sensitive sequences
Acute onset of symptoms
Emergency setting
Early detection of ischemic changes

23. INVASIVE DIAGNOSTIC ANGIOGRAPHIC
PROCEDURES
•
•
Cerebral Angiography
Direct Cerebral Venography
Invasive cerebral angiographic procedures are less commonly needed to
establish the diagnosis of CVT given the availability of MRV and CTV.
These techniques are reserved for situations in which the MRV or CTV
results are inconclusive or if an endovascular procedure is being
considered.

24. Recommendations
• Although a plain CT or MRI is useful in the initial evaluation of patients with
suspected CVT, a negative plain CT or MRI does not rule out CVT. A venographic
study (either CTV or MRV) should be performed in suspected CVT if the plain CT
or MRI is negative or to define the extent of CVT if the plain CT or MRI suggests
CVT
(Class I; Level of Evidence C).
!
•
An early follow-up CTV or MRV is recommended in CVT patients with persistent or
evolving symptoms despite medical treatment or with symptoms suggestive of
propagation of thrombus
(Class I; Level of Evidence C).

25. !
!
•
In patients with previous CVT who present with recurrent symptoms suggestive of CVT, repeat
CTV or MRV is recommended
(Class I; Level of Evidence C).
!
•
Gradient echo T2 susceptibility-weighted images combined with magnetic resonance can be
useful to improve the accuracy of CVT diagnosis70,129,151
(Class IIa; Level of Evidence B).
!
•
Catheter cerebral angiography can be useful in patients with inconclusive CTV or MRV in whom
a clinical suspicion for CVT remains high
(Class IIa; Level of Evidence C).
!
•
A follow-up CTV or MRV at 3 to 6 months after diagnosis is reasonable to assess for
recanalization of the occluded cortical vein/sinuses in stable patients
(Class IIa; Level of Evidence C).